Show us your ugly repair - Page 1
Forum section: electronics / repair

author: TerraHertz
author_rank: Super Contributor
timestamp: June 14, 2016, 01:28:16 am
content: Go on, let us see the most ugly hacks you've ever done. A cathartic admission of shame. Or something.Here's one of mine. A spontaneous repair attempt, still in progress.It began when DavidG asked about a HP 8161 dead part:https://www.eevblog.com/forum/repair/what's-this-part/I have a HP 8160A and manual, with that same CPU board. It's been on the shelf 'awaiting repair' a long time. I opened it for pics to post in that thread, then after putting it back together powered it up to evaluate whether to have another attempt at repair. (Now that I have the manual.)The power supply had infamous Rifa polyester mains caps; one blew up immediately. So suddenly I'm *definitely* attempting repair. Replaced all 7 Rifa caps, then noticed another card in the power supply has 10 wet foil tantalum aluminium-can caps. Checking those, they are ALL utterly kaput. Supposed to be 650uF 20V and 180uF 30V, all axial.For the 650uF I could use some recently bought low ESR 1000uF 16V (yes, lower voltage is OK, the circuit is actually around 7V.)But the others...Urrgh. Due to general lack of cash I don't want to buy from local distributors (and it's the weekend) but I also don't want to wait 6 weeks for an Aliexpress delivery. Hmm.... Oh wait! I recently acquired a huge stock of 'old junk' in nicely sorted containers.https://www.eevblog.com/forum/buysellwanted/free-(aus)-world's-largest-electronics-parts-collection-as-seen-on-eevblog/I'd thought I would probably throw out all the old electrolytic caps, but haven't yet. Are there any suitable for this?Found two tubs, one 220uF 35V, and 470uF 35V. But they are all old, used pigtail, with short desoldered leads. Sigh. But OK, what the heck.Measuring caps from the 220uF tub, they are (as expected) a range of values less than 220uF. Normal electro aging distribution, see 1st pic of some sorted into value ranges. Most still above 180uF and usable for this, but I thought I'd add some extra margin and go for the 470uF ones. These also exhibited an aging distribution, but picking best ones allowed lots of margin.They are of course much bigger than the old wet foil tantalums, and the wrong lead format. Hence the nasty kludge in the 2nd photo. But who cares!While doing this it occurred to me that one use for a *lot* of used, old electro caps, all sorted into value and voltage bins, would be to do a statistical review of exactly how bad they are. By type, manufacturer, etc.

author: xrunner
author_rank: Super Contributor
timestamp: June 14, 2016, 01:30:10 am
content: Uhg - Glee!

author: Cubdriver
author_rank: Unknown
timestamp: June 14, 2016, 03:57:13 am
content: Just for grins, have you taken a crack at re-forming any of them?-Pat

author: vk6zgo
author_rank: Super Contributor
timestamp: June 14, 2016, 04:02:17 am
content: "Fit,form & function"------ the most important of these is "function".The soldering looks OK,it seems mechanically rigid,it works---------OK,it isn't pretty,but Electronics isn't about aesthetics!Most of my time in Electronics was spent in Radio & TV Broadcasting,where equipment was needed "yesterday".A good "bodge" which restored full "in spec" performance was often superior to waiting for the "correct" part to arrive.Three fine "bodges" come to mind:-(1) A 6v supply in an NEC TV transmitter was supplied by a 200v AC rail,which had separate fuses for each module connected to the rail.We inadvertently blew the fuse,which was hidden in the "guts" of the Tx.To get out of trouble,my homemade "VK Powermate"was pressed into service.Various other priorities intervened,& it stayed that way for a couple of weeks!(2)Same place,but I wasn't there at the time.The*28v supply for theFET RF driver stages of a Thomson TV Tx "croaked".*Note edit:-I somehow deleted the "power supply" bit earlier,so it didn't make much sense!!Time for a replacement from France:----------months!Time for local acquisition of parts,& repair.probably months as well.As luck would have it,there was a (very much larger) NEC 28v power supply sitting at the Station I was at,so they borrowed it,set it out on the floor behind the Thomson,made the requisite connections,& away it went,so the people in the area didn't miss their Commercial TV.(3) Later,when I was at the TV Studio,an Electrohome BW Monitor came in for repair.As part of the H output circuitry it used a non-polarised 22uF 400v electrolytic,which was as "dead as a doornail"Looked in the RS catalogue,& there they were-------much smaller physically,too!Marvelling at the advances in technology,I fitted one of these.You've guessed it!-----it lasted 10 seconds!!.It turns out non-polarised low ESR capacitors are quite large.They were also unobtainium,so the "E'home" ended up with a "Christmas tree " of Polyester "greencaps".Ugly?---Certainly!Fully functional?---Definitely!!

author: alsetalokin4017
author_rank: Super Contributor
timestamp: June 14, 2016, 04:22:03 am
content: This was before I knew anything about SMD repair and only had a cheap Weller soldering station to work with.The repair works fine and is still in use today.

author: edpalmer42
author_rank: Super Contributor
timestamp: June 14, 2016, 04:23:47 am
content: But sometimes the ugly repair is the right way to do it.I worked for a telephone company. One day, one of the young engineers was working in the lab on a circuit that just wasn't cooperating. Nothing was making sense. This was a commercial board, we had full documentation and the board was believed to be in good working order. I happened to be there, saw that the young guy was getting frustrated and suggested that he pull the card out of the shelf and give it a good rap on the bench. With a very puzzled look on his face he pulled out the board and gently tapped it on the bench. I said "No, no - like this" BANG, BANG, BANG. "Okay, try it now." It worked. The look on the guy's facewas priceless. Another guy that worked for me saw all this and was practically rolling on the floor laughing.We had both seen multiple mercury-wetted reed relays on the board. Unless the board is kept upright, the mercury will ball up and short the contacts. So the correct, but ugly, repair is to smack it on the bench to shake the mercury out of the contacts! Once I explained it to the young guy, we all had a good laugh.Ed

author: TerraHertz
author_rank: Super Contributor
timestamp: June 14, 2016, 06:32:27 am
content: Quote from: Cubdriver on June 14, 2016, 03:57:13 amHmm... No not really. The ones I ended up using, I first charged up to rated voltage, left to sit unconnected a few minutes then measuring the retained voltage. Purpose being to compare leakage. They were all similar, a few volts down but OK. It was just a test to catch any bad ones.What is the recommended profile for reforming old electrolytics?I certainly have lots of old caps to play with, and it would be interesting to see the results.Oh, and those caps added to the PCB are now hot-melt glued down for extra ugly, and the power supply runs OK. Still to reinstall in the instrument and try to fix that.

author: mathsquid
author_rank: Frequent Contributor
timestamp: June 14, 2016, 11:01:42 am
content: I replaced a ribbon cable in a TI-83+ using stripped wire-wrapping wire. It worked, but the results were ugly.I covered the wires with tape before reassembly, but after this awful picture was taken.

author: wraper
author_rank: Unknown
timestamp: June 14, 2016, 11:46:02 am
content: Repairing broken off micro USB connectors.

author: wraper
author_rank: Unknown
timestamp: June 14, 2016, 11:48:47 am
content: more pics

author: 128er
author_rank: Regular Contributor
timestamp: June 14, 2016, 02:09:57 pm
content: Not my work. But it realy is an electronics nightmare.Got this calibrator nonfunctional from Ebay. The first look at the PCB was like "What the hell? Which Plumber did that?"I only replaced a few defective chips and all the leaked eletrolytics. Yes, they used radial leaded caps with surface mount pads. The thing is one big bodge.

author: 128er
author_rank: Regular Contributor
timestamp: June 14, 2016, 02:11:37 pm
content: More pictures

author: Urs42
author_rank: Unknown
timestamp: June 14, 2016, 02:45:06 pm
content: Don't try this at home (or at work ;-)Before and after:

author: AlfBaz
author_rank: Super Contributor
timestamp: June 14, 2016, 02:48:49 pm
content: This hack is of an FE5680B. A 74F74, dividing the 20Mhz signal down to 10Mhz. Found a bit of space and glued it down, dead bug style.

author: Cubdriver
author_rank: Unknown
timestamp: June 14, 2016, 05:33:48 pm
content: Quote from: TerraHertz on June 14, 2016, 06:32:27 amIf possible I use a current limited supply*, set the open circuit voltage to the voltage rating of the cap (or a bit below), and the current limit to 30 or so mA. Connect the cap and turn it on. Depending on value and how leaky the cap is, it may sit at the current limit for a while as the voltage slowly builds, but if it successfully re-forms you'll eventually see the supply hit the voltage limit setting and then the leakage current will drop off. Let it hang out till the leakage current stops falling then let it sit at its rated voltage for at least a few minutes (longer is better, just for testing's sake if nothing else), then discharge, cross your fingers and test. Datasheets may or may not give acceptable leakage current limits for a given cap, but if this info is available it's definitely something to use to determine the cap's health. There are also some leakage rule-of-thumb numbers in the Sprague TO-4 manual that if I recall correctly apply more to higher voltage electrolytics; I can try to dig them out later if you'd like.*for higher voltage electrolytics used in tube power supplies I get to use my Sprague TO-4 and babysit it, slowly bringing up the voltage manually while monitoring the leakage current. That's a PITA. I need to get my HV current limited supply up and running.This of course will not work for caps that have dried out, and there is no guarantee that it will work for any, but it's relatively easy to do and worth a shot, especially for caps that no longer have easily available replacements. FWIW, if you have several of the exact same type and any are noticeably lighter than the others, the light ones are likely dried out.I've had reasonably good success re-forming caps on HP old test equipment this way, but they were high quality parts to begin with. With consumer grade, all bets are off, but all it costs is a bit of time to try.-Pat

author: T3sl4co1l
author_rank: Super Contributor
timestamp: June 14, 2016, 11:00:36 pm
content: Does this count?Tim

author: joeqsmith
author_rank: Super Contributor
timestamp: June 14, 2016, 11:15:02 pm
content: Here I will demonstrate the proper way to decouple and terminate a high speed digital system. Jumper on A2 is a connection for the scope probe.

author: Samogon
author_rank: Frequent Contributor
timestamp: June 15, 2016, 02:33:47 am
content: Quote from: joeqsmith on June 14, 2016, 11:15:02 pmLike a headcrab from HalfLife.

author: guido
author_rank: Regular Contributor
timestamp: June 15, 2016, 09:43:46 pm
content: Only have the 'before' picture, but got this one working...

author: joeqsmith
author_rank: Super Contributor
timestamp: June 16, 2016, 03:02:27 am
content: Sometimes things are more critical and you need to do some planning before turning on the iron. Here I show how to properly clock some high speed logic.

author: TerraHertz
author_rank: Super Contributor
timestamp: June 16, 2016, 12:15:13 pm
content: @joeqsmithThey are both beautiful. I don't see what anyone could complain about ... electrically.@Cubdriver: "There are also some leakage rule-of-thumb numbers in the Sprague TO-4 manual that if I recall correctly apply more to higher voltage electrolytics; I can try to dig them out later if you'd like."I'd appreciate it. Pic below is my existing electros stock *before* adding the ones in the recently acquired collection. (And I'm pretty sure I missed a cube or two more. Terribly disorganized, due to non-completed storage space shelving.)I won't mix the sets, just add the boxes of 'new' caps that I decide to keep into the storage cube pile these live in.About half of mine are 'new', as in never used. One place I used to work manufactured in large volume, and had a stores/purchasing dept that sometimes chose to throw out large volumes of surplus components. And I was the resident dumpster diver. So, lots of caps but a very limited range of values.

author: SeanB
author_rank: Super Contributor
timestamp: June 16, 2016, 12:47:56 pm
content: Reforming capacitors I used a power supply and a 10k resistor in the one lead, with a voltmeter across the resistor to measure the drop as they charged, then using it to measure leakage. Just put all the ones of the same voltage in parallel and you will reform the lot all at once. Should drop down in current to a low reading after a few minutes, if not divide to see which one is leaking the most and bin it after ripping the leads out of the rubber bung, so you do not try it again.Had to do that with a batch of wet tantalums, which were rejected because of high ESR. Inspector on the other side sent them back, saying " visual inspection passed" so they went back again sans any leads.

author: AF6LJ
author_rank: Unknown
timestamp: June 16, 2016, 02:37:08 pm
content: This thread is fun.

author: Cubdriver
author_rank: Unknown
timestamp: June 16, 2016, 05:35:57 pm
content: Electrolytic leakage limits rule of thumb from the Sprague Tel-Ohmike TO-4 manual - these are, I'm guessing, from the mid to late 50s time frame, so take them with a big grain of salt. I'd say for sure if a modern electrolytic doesn't meet these specs it's toast, as modern ones are likely better than what existed when this was written.The leakage limit depends on the capacitance and voltage rating of the cap, and is calculated from a constant (k) that's based on the cap's voltage rating, the cap's value in uF (C) and a fixed allowance that's added. It says that the caps should sit at rated voltage for at least 5 minutes before the reading is taken, longer if they are still re-forming and the leakage current is decreasing.The formula is: leakage limit (mA) = kC + 0.3k is:0.01 for 3 to 100WVdc caps0.02 for 101 to 250WVdc caps0.025 for 251 to 300WVdc caps0.04 for 351 to 500WVdc capsUsing this, an 80uF, 450V cap would have a leakage limit of 3.5mA (0.04 x 80 + 0.3)a 470uF, 35V cap would have a limit of 5mA (0.01 x 470 + 0.3)The TO-4 manual that this formula came from also notes that caps that have been unused for a year or more may take 30 minutes + to re-form, and suggests limiting the forming current to 10mA or less to prevent overheating. I've thus far had no issues with around 30mA, for what that's worth.-Pat

author: Excavatoree
author_rank: Frequent Contributor
timestamp: June 16, 2016, 06:06:20 pm
content: My repair of my "stand fan" is pretty ugly. I did do a thread about the problem (microcontroller died), but I never described the final repair. No pictures, but it's just an 8 pin PIC 12F509 in a 16 pin spot for some obscure Chinese micro controller. The power and ground pins for the 16 pin were at 5 and 12. (pins 1 and 8 when the 8 pin package is inserted in the right half.) Fortunately, that worked out perfectly for the PIC.It gets ugly because I didn't want to bother implementing the timer, and I only used medium speed. So, I bodged up a simple de-bounced switch program and set the output for the medium speed Triac to 5V. I was disappointed to see the pin corresponding to the "power" switch didn't have an internal pull up on the 12F509. I couldn't be bothered with bodge wires, cutting traces, or adding a pull up, so I just used the "fan speed" switch. The result was a simple drop-in microcontroller replacement, with the elimination of every feature but the medium speed, and using the wrong button.I spent more time tracing the PCB to find out what pin position on the controller did what than I did actually repairing it. The previous repair was a jumper wire from 5V to the medium speed triac. That required me to remove the power plug from the wall to turn it off, so that was a bit too ugly.

author: bitseeker
author_rank: Super Contributor
timestamp: June 16, 2016, 07:04:32 pm
content: Quote from: AF6LJ on June 16, 2016, 02:37:08 pmYeah. Fun, scary, and amazing, all at the same time.

author: wagon
author_rank: Frequent Contributor
timestamp: June 16, 2016, 11:28:26 pm
content: I need to take photos of some of the stuff I resurrect. It is a great thread!

author: SeanB
author_rank: Super Contributor
timestamp: June 27, 2016, 08:23:00 pm
content: Not my work, but this was in a monochrome monitor I scrapped last week at work. Got tired of it sitting on the shelf, and it was working ( and had a lovely series of screen burns on the CRT as well) when I last powered it up. Of course I can no longer display anything on it, as I do not have a computer any more with a MDA or Hercules card that is working.

author: bitseeker
author_rank: Super Contributor
timestamp: June 27, 2016, 08:27:06 pm
content: Nice jumble-o-caps.

author: joeqsmith
author_rank: Super Contributor
timestamp: June 28, 2016, 12:45:00 am
content: Needed the low ESR.

author: bitseeker
author_rank: Super Contributor
timestamp: June 28, 2016, 01:36:56 am
content: Ah, of course. I shoulda thought of that.

author: netman
author_rank: Newbie
timestamp: June 28, 2016, 10:03:19 pm
content: Strange footprint relay I couldn't find a replacement for.

author: bitseeker
author_rank: Super Contributor
timestamp: June 28, 2016, 11:08:28 pm
content: Hopefully, it doesn't fall asleep like that.

author: vk6zgo
author_rank: Super Contributor
timestamp: June 28, 2016, 11:52:31 pm
content: Quote from: netman on June 28, 2016, 10:03:19 pm"A relay is a relay,is a relay"-----with apologies to Gertrude Stein.Form,fit & function---& the foremost importance is function.Out in the real world,things have to be fixed "yesterday",& the niceties of waiting three months for a company somewhere on another continent to fill a seatainer so you can get the correct relay don't hack it.The Boss tells you:"Fix the bloody thing & move on!"

author: TerraHertz
author_rank: Super Contributor
timestamp: July 01, 2016, 09:18:55 am
content: This wasn't an electronics repair, but it was ugly. In the sense of digging pits in mud and dense tree roots, in a hurry since the house had no water until it was done.Tree roots broke the copper water pipe underground in our front yard, with the first visible surface water about a week ago, but we didn't know till Wednesday since the water went straight into our neighbor's yard, and they thought it was just from the recent rains.So Thursday was an all day dig, then plumbing in the dark in the evening, then Friday (today) filling it all back in and cleaning up. I'm knackered.Pics should be self explanatory.Lesson of the day: It's MUCH harder to dig through palm tree roots, than eucalyptus roots.

author: SeanB
author_rank: Super Contributor
timestamp: July 01, 2016, 06:59:30 pm
content: Nice brazing Guy, putting in some soft copper instead of the hard tubing, though I would have put a PVC pipe over them to keep the roots away so they do not crack the pipe further.Does Australia have water loss insurance for burst piping, or is the water cost so low that you only notice on the next bill the use is high.Anyway this was a little test I did this week, to see if this solid block of rust would turn into a micrometer again after spending time in salt air. A little current in a plastic pot filled with acetic acid ( only thing to hand, was not going to use anything toxic like NaOH which was the other thing to hand) and a scrap graphite vane as anode.Still have a few left over, expensive things those vanes, especially if the couriers drop the pump.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: July 01, 2016, 07:59:19 pm
content: Baking soda would be safer than vinegar, but NaOH would be safer as well (just be careful using it).Salt would be bad, as that would make chlorine.Tim

author: TerraHertz
author_rank: Super Contributor
timestamp: July 01, 2016, 11:40:57 pm
content: Quote from: SeanB on July 01, 2016, 06:59:30 pmHa, thanks for saying it, but my silver soldering is crap. Some people seem to be able to end up with the joint nice and shiny, but I don't know how. Feathered reducing oxy-acet flame, trying not to overheat, but while ensuring the silver solder is definitely wicked all the way into the joint I always get a black-looking result. Never mind, it works.The pipe is all hard copper. I happened to have a piece that was just a few inches longer than needed, so the repair was zero cost. Bends are done by heating the desired bend section to red heat to soften it, let it cool, then use an outside spring pipe bender. Easy. The joints are done by heating the end of one piece to red heat to soften the copper, then hammering in a pipe expander tool. Then the end of the other pipe is marked with a felt pen at the required join depth, so you can be sure it really has slid in far enough before silver-soldering. Coat both surfaces with flux, push the joint together, silver-solder. Check the joint underside with a mirror. And then don't drink the tap water for a couple of days till all the fluorine-based flux has definitely dissolved and flushed out.QuoteWell, I put all that pipework in the ground back around 1999. Then after the new house was built, around 2003 some eucalypt seedlings popped up in the back yard. Thinking they would be small varieties like most of the other trees around, I transferred them to the front yard, which I was landscaping around that time. Surprise surprise, they turned out to be very fast-growing enormous trees. The pipe broke directly under one of them. Now they have established major root systems I think the new pipe route is safe. I like the trees a lot, so don't mind this extra work.QuoteI'm informed by a plumber that if given photos of the leak, the water board will adjust the bill to be normal. Fingers crossed that this is true. Hence took a lot of photos.QuoteSo who left it in salt air? Not you? And did your restoration work?Just for amusement, a pic below of other potential carbon electrodes. Some WW2 vintage anti-aircraft searchlight carbon rods (I have a lot of these), and also large motor carbon brushes. (Also have a big box full. Some are pure carbon, others are a carbon-copper mix.)

author: Cubdriver
author_rank: Unknown
timestamp: July 02, 2016, 02:04:39 am
content: I'll bet that bit of tubing is well annealed right now! That does not look like it was a fun project. My fingers are crossed that it's good for at least another 17 years.-Pat

author: ovnr
author_rank: Frequent Contributor
timestamp: July 02, 2016, 02:20:31 am
content: So I needed a PCIe x1 video card. And I wasn't willing to pay a premium for one - or wait for shipping, for that matter.Some dremelling later - and discovering that I cut a couple somewhat important traces - and voila! Like a bought one.

author: bitseeker
author_rank: Super Contributor
timestamp: July 02, 2016, 06:34:06 pm
content: Woah, OK, that's the first time I've seen someone actually do that.This is such a great, quirky thread.

author: SeanB
author_rank: Super Contributor
timestamp: July 03, 2016, 07:18:26 am
content: Quote from: TerraHertz on July 01, 2016, 11:40:57 pmGot it in a pile in a box a while ago, just was trying to see if I could free it, soaked in thinners for a while then decided to try vinegar then the carbon and a spare 12V SLA battery. Put a lot of oil on it Friday and worked it in the screw threads, and tried to get the zero to be closer, but always ended up with the 0.03mm offset, so will live with it. does agree though with the feeler gauges on test side though, so I will just leave it as an offset.

author: Kilrah
author_rank: Unknown
timestamp: July 03, 2016, 08:50:25 am
content: Quote from: 128er on June 14, 2016, 02:09:57 pmWow that one's particularly crazy! Love the IC in the wrong SO package width

author: Rerouter
author_rank: Super Contributor
timestamp: July 03, 2016, 08:52:36 am
content: Quote from: ovnr on July 02, 2016, 02:20:31 amWhy didn't you cut out the back of the pcie socket instead?

author: ovnr
author_rank: Frequent Contributor
timestamp: July 03, 2016, 09:17:10 am
content: Quote from: Rerouter on July 03, 2016, 08:52:36 amThat'd involve potentially fucking up the motherboard instead, which had more value to me than the video card. Also it felt risky as you would be cutting right next to the spring contacts.But most importantly: See the capacitor below the heatsink, to the left of the blue Gigabyte logo? That's directly in line with the slot, and the card would hit it. I actually did two cuts - the slot to make it fit into the connector, and also a bit over half the total edge connector. So first from x16 to x6 or so, then a slot to make it fit into the x1 slot. It's fairly visible - notice the lack of PCB underneath the AC coupling caps on the video card, under the mobo heatsink.

author: Kilrah
author_rank: Unknown
timestamp: July 03, 2016, 10:45:13 am
content: Ah. The photo doesn't really make it apparent that you did another cut further back, thought it was only the slot.

author: razberik
author_rank: Frequent Contributor
timestamp: July 26, 2016, 09:33:27 pm
content: My girlfriend broke some plastic part on her Marshall headphones. Remain was lost.Took me about 3 hours to fabricate the part of aluminium sheet. It doesn't fit well anyway and it is ugly, but it works.

author: vze1lryy
author_rank: Regular Contributor
timestamp: July 27, 2016, 05:25:14 am
content: Here's pic one...

author: vze1lryy
author_rank: Regular Contributor
timestamp: July 27, 2016, 05:28:52 am
content: Here's pic 2 & 3A power line was shorted to ground inside the board. Everything on that line had to go on a wire outside the board, every component on that line had to be re-routed or moved to something else... the inrush FET can be seen stuck to the fan.This still works 11 months later. It was one of my most fun repairs to do, it took about 40 minutes and the guy was watching the entire time. I wouldn't do it again, but it is cool to do it just to see if it can be done, so I can cross it off the bucket list.

author: Kilrah
author_rank: Unknown
timestamp: July 27, 2016, 06:14:24 am
content: Wow

author: elex_enthusiast
author_rank: Regular Contributor
timestamp: July 27, 2016, 07:50:26 am
content: Fixing an intermittent shutdown problem of an old Toshiba laptop of a friend which turned out to be a defective proadlizer cap (well it's been a common issue with proadlizer caps failing on old Toshiba laptops).

author: Whales
author_rank: Super Contributor
timestamp: July 27, 2016, 08:14:32 am
content: vze1lryy:How did you conclude a whole rail was shorted on the mobo? How did you even trace that rail to every part that needed it? It sounds like you had access to the laptop's schematics.Everything in this thread looks beautiful to me. Too many people assume electronics is all about final, clean PCBs and mass-production techniques; because that's all they have seen in their lives. Hell this thread is teaching me lot.I was trying to fix an encoder on my HP 54600A scope about a week ago. I pulled it apart, cleaned it, inspected the wipes and regreased it to no effect. The day after I that I discovered that I had pulled and cleaned the completely wrong encoder. Note to self: don't start repairs late at night.Unfortunately the encoders HP used are not made to be serviced. Instead of having nice bendy metal tabs like some pots do, they have these cast triangular spikes holding on their back plates:For the first encoder I painfully bent the back plate until it would lift off. Putting it back on was difficult too and it did not look very nice after.For the second encoder I gently snapped the triangular stakes off the casting with light squeezes of my pliers. This left the backplate intact, but no method to secure it back on.I initially hot-glued it back on, but this was not satisfactory. Especially since this backplate would fall onto the PSU inside the scope if it popped off during use. The solution? Press on the control until it fails, try again with 2x the hot glue, rinse and repeat until we are several times above the failure point for severe control pressure:I need to track some replacement encoders down. Even if I use a better adhesive/clip, my grease was too thin, and the controls are noticeably different.Oh, and the problem with the dodgy encoder was not too hard to spot. Here are the wipers attached to the shaft you rotate:Keep these images and stories coming!

author: vze1lryy
author_rank: Regular Contributor
timestamp: July 27, 2016, 04:47:40 pm
content: Quote from: Whales on July 27, 2016, 08:14:32 amMaybe!Boardview and schematic definitely help. I removed every component from the line and it still had a dead short to ground.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: July 27, 2016, 05:11:59 pm
content: Even without schematics, it's not hard to tell, from the components and layout, what's connected to the main power rail.IIRC, my laptop has five supplies connected to a common 14-19VDC rail. One's for battery management, the others are VCORE, 1.8V, 3.3V and 5V (or presumably something like that; I didn't measure). YMMV, but it's a pretty good approach, and likely many laptops follow a similar pattern.All those converters have pairs of transistors (they're all synchronous buck type, in my case), and you can easily measure the high side source being connected to that common rail. Or, in the above repair case, you'd have the peculiar problem that PMOS sources are grounded...Tim

author: Stefan Payne
author_rank: Contributor
timestamp: July 29, 2016, 12:39:55 am
content: Quote from: ovnr on July 02, 2016, 02:20:31 amWell, yeah, that's one way to do it...The other way to do it is to open the PCIe Slot, that's what I did on my HP/compaq thingy with Q963 Board (forgot what it was) - and plugged a HIS Radeon HD5750 into it...

author: ovnr
author_rank: Frequent Contributor
timestamp: July 29, 2016, 01:04:42 am
content: Quote from: Stefan Payne on July 29, 2016, 12:39:55 amAs I said in a later post, I was more attached to the motherboard than the video card. Also, cutting near the somewhat fragile socket pins did not fill me with a great deal of enthusiasm.

author: v8dave
author_rank: Regular Contributor
timestamp: July 29, 2016, 04:57:28 am
content: After my client stuffed 110Vac into the board instead of 24Vdc, this is a result of the repair (one regulator still to be installed). It seems that the failure stopped at the regulators which were all damaged and the 3.3V and 5.0V devices on the board still work. There used to be a poly fuse where the copper is missing so I fitted a new Littelfuse to the side of this.

author: samnmax
author_rank: Regular Contributor
timestamp: July 29, 2016, 11:47:16 am
content: Quote from: elex_enthusiast on July 27, 2016, 07:50:26 amYour repair is not ugly at all, compared to mineThis was an Acer 18" laptop.

author: Electronoooob
author_rank: Unknown
timestamp: August 19, 2016, 02:43:39 pm
content: Quote from: 128er on June 14, 2016, 02:11:37 pmthat has some great character

author: Electronoooob
author_rank: Unknown
timestamp: August 19, 2016, 02:49:53 pm
content: Quote from: vze1lryy on July 27, 2016, 05:25:14 amdeargod

author: SeanB
author_rank: Super Contributor
timestamp: August 19, 2016, 06:16:38 pm
content: Temporary adjustment so it would not leak, and today I replaced the diaphragm, along with replacing almost all the M5x12 CSK stainless steel screws that hold the assorted parts together, I cammed a few getting them out to do the quick adjustment, and got new ones along with a new 3mm hex key to make sure I did not damage the new ones.Still had one that decided to play coy, so had to do a little "persuasion" using a hammer and a cold chisel to get it moving out enough to undo fully.New diaphragm to place in storage as spare arriving Monday, this one lasted pretty well, replaced in 2013. The rubber ones used before never lasted that long, they typically only last a year before tearing, which can be a little messy. Polypropylene fabric ones are a lot better, and are as a bonus a lot cheaper. I can even get them in ballistic Nylon, or for really rough applications in PTFE. Looked at the ( hand written) label, and it was made in 2001, I guess they do not move very fast.

author: TerraHertz
author_rank: Super Contributor
timestamp: August 21, 2016, 01:17:35 am
content: Quote from: SeanB on August 19, 2016, 06:16:38 pmHow the heck does that work? And what sort of flowing material is it for?Here's something kind of ugly, not really a repair, and not electronics.A friend brought a found large tower PC case round on Friday night. He needed it to fit a new over the top motherboard with some huge CPU cooling system. (Which I haven't yet seen.) Anyway, he wanted the case front to look 'industrial' as opposed to standard office crap.So here it is, industrialized. Yes, that's the new front. Red button is the power momentary action, black button is reset (and is a military high-force type.) Two LEDs to go in later. He's not sure if he'll anodize it, or just leave it plain aluminium.He didn't want any drive slots or USB ports. The machine will be all solid state drive(s), with USB hub nearby.

author: SeanB
author_rank: Super Contributor
timestamp: August 21, 2016, 01:09:22 pm
content: Quote from: TerraHertz on August 21, 2016, 01:17:35 amAnodise it to be almost white, and dye it black or blue, depending on the surrounding equipment.The valve is a Mucon AD6.http://muconusa.com/products/ad-series-iris-valve/Used for controlling the flow of powder by me, though they have been used for many things, including controlling the flow of fish in a pond.

author: TerraHertz
author_rank: Super Contributor
timestamp: August 22, 2016, 04:22:39 am
content: Quote from: SeanB on August 21, 2016, 01:09:22 pmBut that would make it look almost attractive, and that's the opposite of what he wants. I had a ride in his latest car that evening too. It's a sleeper. Looks like some crap dirty beat up small old Jap car. But it's terrifying. The guy who modded it lost his license almost immediately, but my friend is more circumspect. Same effect intended with the PC.QuoteThat's interesting. So there's nothing exposed to the flow medium but the stretchy plastic liner?One of the things my vacuum project needs is a large diameter diaphragm valve, for throttling the turbo or diffusion pump, to allow controlling very low gas pressure and flow-through in the working chamber. Not yet sure how to do it; thanks for the link.

author: jonovid
author_rank: Super Contributor
timestamp: August 22, 2016, 05:57:33 am
content: My ugly hack is on a poor little Chinese mini DV Camera. so I can add an interface too it with Arduino.

author: w2aew
author_rank: Super Contributor
timestamp: August 22, 2016, 01:49:41 pm
content: My "ugliest" repair, at least in terms of the "custom" work that I had to do, was replacing some IF filters in a Kenwood VHF/UHF transceiver where I had to install extra series caps to remove the DC bias from the filter. Here's a video of the repair (real ugliness starts at about 10:54 in the video):

author: Cyberdragon
author_rank: Super Contributor
timestamp: August 23, 2016, 07:54:08 pm
content: I have lots but most I'd have to take stuff apart to show them. Heres one I can show now though.Notice something?

author: bitseeker
author_rank: Super Contributor
timestamp: August 23, 2016, 11:28:08 pm
content: Quote from: Cyberdragon on August 23, 2016, 07:54:08 pmThe photo is a bit out of focus, but apart from the "X" on the caps, I see a cylindrical thing floating in midair in the upper right quadrant of the pic. What is that? A flying bodge?

author: Cyberdragon
author_rank: Super Contributor
timestamp: August 24, 2016, 12:35:22 am
content: Quote from: bitseeker on August 23, 2016, 11:28:08 pmSorry for blurr, low res android cam pic. Those "X"s are actually "+". There are 4 floating trimmers, two at the bottom and two in the middle. The blue thing at the bottom, a small brass one on the opposite side of the transformer, the one you see in the middle, and a small brass one behind it. The trimmers kept failing open or intermittent/noisey and I don't have the right values in that style.

author: lowimpedance
author_rank: Super Contributor
timestamp: August 24, 2016, 12:36:09 am
content: An Exact function generator !?.

author: Cyberdragon
author_rank: Super Contributor
timestamp: August 24, 2016, 12:59:29 am
content: Yep, Exact model 126. Still has a bit of noise on the low frequencies, maybe more bad trimmers.

author: bitseeker
author_rank: Super Contributor
timestamp: August 24, 2016, 04:55:17 am
content: Quote from: Cyberdragon on August 24, 2016, 12:35:22 amWow, four flying trimmers. Fun and ugly repair!

author: Cyberdragon
author_rank: Super Contributor
timestamp: August 25, 2016, 12:34:50 am
content: You haven't seen the floating HV caps yet. Those are hidden away in some tube stuff where no one can see them. I do put electrical tape on the leads if the wires aren't tight enough to keep them from flopping around but still...Wait...found one...The cap in the middle bounces when poked (several hundred volts when on).It's nippon chemicon though.

author: TerraHertz
author_rank: Super Contributor
timestamp: August 30, 2016, 01:33:57 pm
content: Here's another. Does this win "Tiniest Ugly Repair" ? (Ha, what am I saying? Very likely someone can beat this.)I'd been given three Dell S500wi short-throw Projectors, all with some problems. The first was an easy non-electronic fix, this second one had a dud main fan, so would rapidly shut down with an overheat warning.Unfortunately the fan has a custom frame, so couldn't easily be swapped with any other. Either fix it, or trash the whole projector. The second option was quite tempting, since I'd like to take the optics path apart from curiosity. Also it seems stupid to try and fix a fan, but I thought I'd have a quick try.So much for 'quick', it turns out that to remove the fan requires almost completely disassembling the machine, just to get at the 4th fan mount screw. Brilliant design.The fan is a standard 3-pin type; gnd, +12V and tacho output for fan fail sense.It was trying to start, with small jerks of the rotor. Spins freely by hand, so... something electronic dead in the fan drive pcb. Like most fans the rotor comes out easily - peel off the label and remove the circlip on the shaft.But then there's a problem - the poles and drive PCB assembly is solidly glued to the central plastic mount.Needed some way to apply force, without damaging the fairly delicate pole pieces. I found a bit of brass tube that was a near fit to the poles, cut a slot in it, and clamped it tight on the poles with a pipe clamp. With that as a handle, NOW it comes off!The board is pretty standard - a control IC (On semi, LB11970RV) and a typical Hall Effect sensor (marked "7", very helpful.)Found the data for the drive IC, gave the board power and started probing around the IC. Everything seems OK, except that the two signals from the Hall sensor are nowhere near the same voltage. One is near ground, and noisy. I thought they were supposed to be the same with no B field?I pulled apart another old fan picked from the junk box at random. With that one's board powered, the hall effect sensor outputs are the same. Putting a magnet near it produces nearly a volt differential, polarity reversing if the magnet is flipped. Yeah, I thought so. And generally they are all passive, so fingers crossed, I can substitute this one in. And with luck it will even be the right polarity, since it's just a square of semiconductor with contacts on the four sides brought out to pins, and flipping it around shouldn't make any difference.Ha ha, except I think I'd better preserve the + and - power pins polarity. And of course Murphy ensured given that constraint, this one is a mirror image of the dead one. OK, so I will mount it upside down.So there it is, soldered dead-bug style.And it works!

author: bitseeker
author_rank: Super Contributor
timestamp: August 30, 2016, 05:54:59 pm
content: That is a tiny repair, TerraHertz. As I was reading, I thought you were going to do some kind of ugly bodge on the projector's main PCB that drives the fan or something. Swapping in the PCB from another random fan was cool.Although the upside-down dead bug and solder blob do qualify as an ugly repair, I think that overall it's a bit too good for this thread. Next time, duct tape an old AC fan to the exterior of the case!

author: TerraHertz
author_rank: Super Contributor
timestamp: August 31, 2016, 01:44:36 am
content: Quote from: bitseeker on August 30, 2016, 05:54:59 pmThanks! But I swapped the hall effect sensor, not the PCB. I think you typoed?QuoteAww, and I deliberately left that solder blob to improve it's qualifications for this thread. (Also, because scared of heat-killing the sensor, and the blob makes no practical difference.)Actually these projectors are rather useless to me, since they require a very flat projection surface otherwise the image is nastily distorted due to the highly oblique light path. So I'm going to see what I can get for them on ebay. They work well when set up as intended, but that setup is finicky. As online reviews repeatedly complain about.

author: bitseeker
author_rank: Super Contributor
timestamp: August 31, 2016, 02:46:34 am
content: Quote from: TerraHertz on August 31, 2016, 01:44:36 amYes, indeed, I was typing too fast. It's "ugly typing".QuoteHehe. I believe you are the first one I've seen to actually repair one of those little fans.QuoteeBay FTW!

author: TheBay
author_rank: Unknown
timestamp: September 14, 2016, 09:47:26 am
content: Broken laptop, USB Connector had been snapped off and the board damaged.Someone had previously tried to repair, the SD Card socket needs to be removed to get to the USB port solder points.Tracks damaged going to SD Card socket, carefully removed SD Card socket, removed broken USB socket, fitted new part.Re-fitted SD Card socket and used solid wire to repair tracks on board, solid wire soldered to SD Card socket pins and then to 0201 resistors.All done with a Weller WSD80, ugly repair but works. Saved board going for scrap.

author: setq
author_rank: Frequent Contributor
timestamp: September 14, 2016, 12:49:47 pm
content: No photo unfortunately but 30 feet of my garden's lap fence panels were held together for 5 years with CAT5 patch leads and cable ties after a storm took them out.

author: bitseeker
author_rank: Super Contributor
timestamp: September 14, 2016, 05:51:25 pm
content: Wow, a fence held together with CAT5. First I've heard.

author: TheSteve
author_rank: Unknown
timestamp: September 14, 2016, 06:05:45 pm
content: I'd never thought of networking my fence before.

author: VK5RC
author_rank: Unknown
timestamp: September 15, 2016, 03:02:49 am
content: My metal fence is part of my rf ground plain network :-)

author: T3sl4co1l
author_rank: Super Contributor
timestamp: September 15, 2016, 03:15:19 am
content: Quote from: VK5RC on September 15, 2016, 03:02:49 amIf you had used rainbow colored CAT5, it could've been a ground fancy network.Tim

author: VK5RC
author_rank: Unknown
timestamp: September 15, 2016, 06:20:51 am
content: Should have used cat5 cable, then I would have an iFence!

author: SeanB
author_rank: Super Contributor
timestamp: September 15, 2016, 07:59:57 pm
content: There is a pic on Reddit of a BMW with the front lower control arms held together with random network cables and other wire.Don't think I would srive in it, and I have seen some real bodges here, including a vehicle with brake linings made from cardboard.

author: setq
author_rank: Frequent Contributor
timestamp: September 15, 2016, 08:39:54 pm
content: Another bodge I just remembered from a physics supply teacher I had. He had a flat on his bicycle, pumped it up a bit, soaped up the wheel with some hand soap, found where the hole was. No puncture repair kit and no spare tube available. So he confidently proceeded to pump it up with a car foot pump borrowed off another teacher in a large bucket of water. Due to the ridiculous amount of friction this took about half an hour and probably ruined the pump.Logic here: H2O molecules were larger than O2/N2 etc so they'd take longer to come out. Long enough to get home.He was right. It didn't come out. But he forgot that it was nearly impossible to ride with a front tyre that weighed as much as the rest of the bike, hit a drain cover, lost it completely, went flying and smashed his face on the ground.

author: bitseeker
author_rank: Super Contributor
timestamp: September 15, 2016, 09:21:35 pm
content: Ouch! Ugly repair lands ugly result.

author: VK5RC
author_rank: Unknown
timestamp: September 16, 2016, 09:58:34 am
content: I think one of the finer points of the "Art of Bodging" is to know when to stop and throw the bl**dy thing away!

author: bitseeker
author_rank: Super Contributor
timestamp: September 16, 2016, 08:51:49 pm
content: After desoldering the good bits.

author: tatus1969
author_rank: Super Contributor
timestamp: October 02, 2016, 11:08:48 am
content: it is not exactly a repair, but it is uglyWhat you see here is my attempt to modify an existing circuit to do something completely different (measuring an inductor's Q factor) than before (measuring its inductance). I ended up reusing only the SOT363 comparator and it's bypass cap, and adding all the restsomehow.The heat compound nicely adds to this mess.

author: DimitriP
author_rank: Super Contributor
timestamp: October 04, 2016, 07:06:54 pm
content: After one of the heatsink retainers flew off to another dimension.

author: All2skitzd
author_rank: Newbie
timestamp: October 05, 2016, 06:51:41 am
content: 9800GT for free. Fan was bad so I cable tied a Dell rackmount server fan on it and added a cigarette pack shroud

author: kakureru
author_rank: Contributor
timestamp: October 08, 2016, 05:22:27 am
content: Person was not too thrilled to continue the use of a monitor that set off many smoke detectors and caused a near office evacuation...

author: richfiles
author_rank: Regular Contributor
timestamp: October 08, 2016, 06:43:17 am
content: i don't have pics, but at my old employer, we had three magnetizers (for magnetizing rotors for motor manufacturing)... Not relevant to the repair, but certainly a very impressive machine, was "Big Blue", a machine that took three full depth, full height 19 inch racks, with 2.5 of the rack space filled with capacitors, and the other half rack's worth of space containing the actual electronics... That was a BEAST of a machine, and did once put someone in the hospital when it vaporized a magnetizer winding that had been improperly connected...Anyway, this is not about "Big Blue"... This is about a smaller unit that I once repaired. It had a mercury filled glass tube thyratron as it's trigger, and it had failed. It was an older machine, and the thyratron was pretty expensive for it. I was one of the site technicians, and I unbolted the thyratron, and started to "gently violently" shake it. I got some odd stares... I reassembled the unit, and it worked beautifully.Over time, mercury would deposit on the outer glass, and sometimes on other internal structures. This eventually shorted it out, in such a manner, that it'd never allow the capacitor banks to fully charge... It'd always trigger early. Shaking the tube basically, "washes" the mercury residue off everything that does not need it, and coats everything that does need it... Well, thats the simple answer I gave, anyway. It was a simple fix, and the machine continued to operate right up until we were eventually bought out by a bigger company and our site closed down.

author: martonmiklos
author_rank: Contributor
timestamp: October 08, 2016, 10:10:19 am
content: This one was performed years ago by one of my friends, but I think it worth sharing here. He was awarded the "ditching of the year" between the buddies for this.He repaired a MSI - EX630 notebook which had a faulty power rail caused by a dead SMPS power supply controller IC. The IC was hard to source and had a very long shipping time and -as always- the client wanted to use his machine as soon as is possible.He removed the output choke and the controller IC from the faulty power rail and he cut a power supply PCB part (with similar ratings) from an another notebook motherboard with his Proxxon drill. He adjusted the feedback loop with a helitrimmer to match the necessary voltage. Then he wired back the power rails and the enable and the fault signals back to the motherboard. It worked perfectly until the original SMPS controller arrived and the original power supply topology restored.https://www.dropbox.com/s/9k9qxvr1ij4kwhz/IMG_0035.JPG?dl=0https://www.dropbox.com/s/23xz6id3iinjx21/IMG_0036.JPG?dl=0https://www.dropbox.com/s/0kvn8e2ws72zy52/IMG_0039.JPG?dl=0

author: pa3weg
author_rank: Contributor
timestamp: October 08, 2016, 09:25:01 pm
content: This one is to replace a design F*ckup that was using a special IC to do a certain job (signal conditioning)Could also be done with an op-amp circuit, but that did not fit the socket.So I did some serious landscapingI can not find a picture with the thing installed, I will dig a bit further.

author: wine+dine
author_rank: Contributor
timestamp: October 09, 2016, 09:41:13 am
content: Ah yes, landscapingThis CA3046 from a Tektronix 7603 had one bad transistor (C-E short).With no spare at hand initially, and to avoid blowing another anyway, here's an ugly hack to continue troubleshooting.It survived, and through an accidental deep search of the parts bin, a replacement has since turned up ...

author: kakureru
author_rank: Contributor
timestamp: October 09, 2016, 05:52:51 pm
content: Who remembers the sampo firmware hacks, this caused the specific line of EEPROM prices to spike during those years. Fortunately I found a nice alt at a fraction of the price but required an "adapter" (It was also slower but aside from menus loading a tad slower, it DVD player had little problem with it.)(this was from 2002) I have a grainy pic of it installed somewhere.

author: richfiles
author_rank: Regular Contributor
timestamp: October 10, 2016, 04:25:49 am
content: Blower motor went out on my home's central air unit in the peak of summer. I don't recall the price, but they wanted some ridonkulous amount to replace it.I duct taped a car radiator fan over the side panel, and put in a sheet of solid cardboard between the filter and the intake ducts. It pulled air in from the basement, which is fine as long as the basement door was left open so air could circulate. I powered it from a car battery charger. ran like this for a couple days, till I salvaged aproperreplacement blower motor from scrap for about $30.If i recall, i think I twisted the blower power wires onto the prongs of the battery charger plug and wrapped the crap out of it with some electric tape.

author: Zom-B
author_rank: Regular Contributor
timestamp: October 19, 2016, 09:49:59 am
content: What to do when your CCFL backlight driver is fubar?First image is old. Other images are the current version with relay and switch.(Detatched keyboard unrelated)

author: setq
author_rank: Frequent Contributor
timestamp: October 19, 2016, 10:16:56 am
content: Quote from: wine+dine on October 09, 2016, 09:41:13 amI actually really like that one. I did something similar with a CA3096 in my function generator's DC offset amplifier. The thing had an open transistor in it, fortunately only Q3 which was is as the tail resistor in a diff amp so I snipped the legs off the IC and wedged a 2n3904 over the top of the IC and into the socket. Worked fine and still does to this day.

author: TheBay
author_rank: Unknown
timestamp: October 19, 2016, 01:43:19 pm
content: Quote from: kakureru on October 09, 2016, 05:52:51 pmWow thanks for jogging my memory, I'm certain I used to repair Sampo and Sampo rebadges in a place I worked once, my memory is very vague but forgot all about these.They were everywhere in the UK as you could make them region free and were quite cheap too.Nice hack with the adapter!

author: sidspop
author_rank: Contributor
timestamp: October 30, 2016, 09:04:03 am
content: No pictures unfortunately.A chap brought me a Kenwood TS50 ham radio years ago with an intermittant problem.Sometimes it would work, sometimes it wouldn't, but a smack on the top made it function.It transpired it was a bad connection somewhere on the main board, and by pushing it down by all of half a millimetre it would function perfectly.After messing with it for an hour or so, we came to the conclusion that some CAB was needed. Cardboard Aided Bodgery.A small bit of card, taken from a cigarette paper box, folded up and positioned, and the covers replaced. To this day the radio still works, about 20 years later.

author: EPTech
author_rank: Regular Contributor
timestamp: July 26, 2017, 08:21:00 am
content: Hi there,A family member asked me to look at his Iphone 6. His screen had been replaced and U2301 had been chipped of in the process, including 3 pads. He already ordered a replacement part, a 4 pin BGA of about 1x1mm. In the picture (sorry about the poor quality) you can see how I flipped it upside down, soldered 4 0.05mm wires to it, and attached those to other connections in the circuit. I painted the entire thing over with rework lacquer so the IC and the wires are fixated. It was a nice experience.Greetings.