hybridfree/eevblog-posts huggingface dataset:
LIEBHERR 71ECB - Page 1
Forum section: electronics / repair

author: EEVaditya
author_rank: Regular Contributor
timestamp: August 20, 2017, 04:12:33 am
content: Hello,The Tower crane part specifications are as follows:Make:LIEBHERRLIEBHERR 71ECBMat.No.15F5ABE-YH02The problem:After starting the crane it gets jerk and the lights go dim momentarily,can anyone guide what would be the exact cause? and the solution for it?Also,for the above mentioned part specifications where I will get the technical specifications,like power consumption and so on. In datasheet they have not mentioned this information.

author: PartialDischarge
author_rank: Super Contributor
timestamp: August 20, 2017, 06:59:56 am
content: Once upon a time I wanted to buy one of these cranes for my lab, you know to move HP gear and my Tek 7104 around, but I realized it wouldn't quite fit.

author: Whales
author_rank: Super Contributor
timestamp: August 20, 2017, 08:03:47 am
content: EEVaditya: what have you already tried?Have you contacted anyone knowledgeable about cranes, or that builds/repairs them?I'm not sure that an online forum is the best place to get advice on something as massive, dangerous and regulated as a construction crane. Good luck

author: capt bullshot
author_rank: Super Contributor
timestamp: August 20, 2017, 08:58:38 am
content: The Liebherr website states 32kW total power for the drives, using VFDs.You'll need a power supply with a good amount of extra power to deal with the variable frequency drives. A long and too weak supply line may cause heavy distortions on the power supply, leading to all kinds of misbehaviour.
Need help identifying this FET driver ! - Page 1
Forum section: electronics / repair

author: Giorg
author_rank: Contributor
timestamp: July 25, 2017, 03:53:06 pm
content: hello forum! I need your help to identify this IC.I'm trying to fix a battery charger and this IC becomes really hot so at the moment it's the number one suspect.Markings are abraded. From some quick probing(diode from VCC) -- -- OUT 1VCC -- -- GNDIN1 -- -- OUT 2IN2 -- -- OUT 32kGND -- -- VCCGND -- -- GNDVCC -- -- OUT 4GND -- -- (diode from VCC)IN1 and IN2 are coming from the main uC.VCC is 5Vpackage SOIC 16I think is a quad FET driver but I cannot find a matching pinout... anyone has a clue ?

author: capt bullshot
author_rank: Super Contributor
timestamp: July 25, 2017, 04:24:22 pm
content: http://www.intersil.com/content/dam/Intersil/documents/hip4/hip4082.pdf

author: Giorg
author_rank: Contributor
timestamp: August 19, 2017, 04:25:50 pm
content: I owe you a beer ! I've looked at that IC before but I misinterpreted the pinout. Thank you! I've also found 2 mosfet damaged and got it working again.

author: capt bullshot
author_rank: Super Contributor
timestamp: August 19, 2017, 05:34:46 pm
content: Cheers!Good work
Power Supply for Tektronix DPO2000B Series Scope - Page 1
Forum section: electronics / repair

author: paschulke2
author_rank: Contributor
timestamp: August 17, 2017, 07:36:06 am
content: Does anybody know whether the power supply modules for the DPO2000 and the DPO2000Bseries oscilloscopes are the same? I managed to find the service manual for the 2000 (withoutB) series and from the looks I'd say they are the same (part number 119-7266-00).Just in case you want to ask: "Why don't you ask Tektronix?" I did. The gave me the part number for the mains cable ...Thomas

author: paschulke2
author_rank: Contributor
timestamp: August 18, 2017, 01:49:10 pm
content: Now I've received a second answer from Tektronix: The power supply for the DPO2000B series is not available at all, not even the 119-7266-00 for the DPO2000 series. They would not tell me if the power supply in the B models is the same. Note that the DPO2024B is still a current model.I've just found out that I still have 8 months of warranty. I thought I had bought it more than five years ago ...Thomas
Identify a component in this circuit? - Page 1
Forum section: electronics / repair

author: f114
author_rank: Newbie
timestamp: August 17, 2017, 03:37:23 pm
content: Would anyone know to identify that component that has the arrow that indicates only "BD1" ?.

author: Tom45
author_rank: Frequent Contributor
timestamp: August 17, 2017, 03:42:03 pm
content: Ferrite bead inductor.
Repair LED grow light - Page 1
Forum section: electronics / repair

author: Geronimosport
author_rank: Newbie
timestamp: August 14, 2017, 08:48:10 pm
content: I am a complete newb and am confused on LED power supply equivalents. The part I need to replace is a RoHS (is that a cert or a brand?), Model NLNI-50XC-035A and it says Input 100-240VAC 50/60Hz Output 80-130v DC, 650mA. Replacements I find are showing in watts and I am not sure what I need to buy. I looked on the usual suspects but my Googlefu is weak on this one. Can someone point me to a part? Tell me what I need? Thank you in advance.Kenneth

author: sokoloff
author_rank: Super Contributor
timestamp: August 15, 2017, 12:35:24 am
content: You might be able to buy the exact replacement from here:http://www.nldriver.com/product/product225.htmlIt appears to be a constant current driver. You say 650mA; the spec I found above says 300mA.Once you decide which it is, you can just look for another constant current LED driver with the appropriate input and output voltage. I didn't find any with a quick search, but I only spent 3 minutes on it. You are presumably more motivated than I am.In order of priority, you want the right current rating, then the right input voltage rating, then the right output voltage. You can compromise slightly on the last one, perhaps.RoHS is a certification ("Reduction of Hazardous Substances", meaning lead free solder, among other things)

author: Geronimosport
author_rank: Newbie
timestamp: August 15, 2017, 05:05:04 pm
content: Thanks for the help, that is what I need just my Chinese is not very good, so that site is not usable for me. Was thinking this would be simple! will keep looking.Kenneth

author: jmelson
author_rank: Super Contributor
timestamp: August 15, 2017, 07:18:07 pm
content: Digi-Key stocks several THOUSAND LED lighting supplies. Their search engine should be able to narrow it down by current and voltage rating.Jon

author: Toasty
author_rank: Regular Contributor
timestamp: August 17, 2017, 07:27:34 am
content: Why not repair what you have?
Fluke 179 dc current offset issue - Page 1
Forum section: electronics / repair

author: hugo
author_rank: Regular Contributor
timestamp: August 18, 2017, 02:10:13 am
content: Hi guys,I've bought a Fluke 179 meter from evil bay, 3 years ago, that shows 200 uA offset on the DC/mA position and 2 mA offset on the DC/A position. I've discovered the issue only now.Has anyone seen or been able to cancel this offset somehow without a recalibration $$$ ?Thanks

author: retiredcaps
author_rank: Super Contributor
timestamp: August 18, 2017, 02:25:38 am
content: Quote from: hugo on August 18, 2017, 02:10:13 amSee if this thread helps you?https://www.eevblog.com/forum/chat/fluke-87v-non-zero-current-reading/
Help needed: filter module for Ikea combioven MWC 6 - Page 1
Forum section: electronics / repair

author: MaximG
author_rank: Newbie
timestamp: August 16, 2017, 08:10:55 pm
content: Hi all,could someone help me to identify the part which blew up here (see attached image)? It is the same module as this one:http://www.europart.nl/c/onderdelen-koken/ikea/oven-magnetron/elektronica/ikea-condensator-480120100526-amw510-amw525-emccd6244-92750130TIA!

author: jmelson
author_rank: Super Contributor
timestamp: August 16, 2017, 08:22:05 pm
content: 2.2 uF 305 V, from the europart item. Geez, 128 Euros for 5 Euros in parts?!? That's crazy!Get a 350 V or higher-rated one, if you can, 2.2 uF film capacitor, and you should be fine.Jon

author: madires
author_rank: Super Contributor
timestamp: August 16, 2017, 09:00:56 pm
content: Standard X2 filter cap with 2.2µF.

author: MaximG
author_rank: Newbie
timestamp: August 17, 2017, 10:46:35 am
content: Thanks a lot everyone, much appreciated.
Wavetek/Meterman BDM-40 Service Manual or Schematic - Page 1
Forum section: electronics / repair

author: floobydust
author_rank: Super Contributor
timestamp: August 16, 2017, 06:26:47 pm
content: Wavetek BDM-40 dumpster find and looking for the service manual or schematic. Can't find anything on it other than User manual.It also went under the Meterman or Amprobe brand labels.Benchtop 4-1?2 digit (20,000 count) LED with True RMS.
Trouble with Iwatsu ss5711d oscilloscope - Page 1
Forum section: electronics / repair

author: andrejsstrumfs
author_rank: Newbie
timestamp: August 14, 2017, 06:36:02 pm
content: Hi everyone!Couple of weeks ago i got a cheapish Iwatsu-5711d oscilloscope, which all in all works ok with one slight problem i would like to fix. The problem is - it won't trigger from channel 2, while triggering from ch1 and ch3 is ok. So i got a manualhttp://exodus.poly.edu/~kurt/manuals/manuals/Other/IWATSU%20SS-5711%20Instruction.pdf, hooked up ch2 to calibration source and started poking around with my other oscilloscope.Trouble looks to be in the ch2 pre-amp circuit (page 111 in manual) - at first it looked like dead Q35 transistor - when i unclipped the P90 connector i got the same signal but with ~2x smaller amplitude when compared to ch1 trigger output. But with the connector on there is no signal at all. So i removed the transistor, checked for shorts and replaced the transistor with a new one. And got the same problem. Power sources are all ok. Resistors arund Q35 are all ok. Maybe someone can come up with idea?RegardsAndrejs

author: edavid
author_rank: Super Contributor
timestamp: August 14, 2017, 07:18:15 pm
content: Quote from: andrejsstrumfs on August 14, 2017, 06:36:02 pmThat's the first thing to fix. Shorted cable or switch?

author: andrejsstrumfs
author_rank: Newbie
timestamp: August 14, 2017, 07:28:49 pm
content: QuoteYup, that was the very first thing i thought. But nope, the resistance for both ch1 and ch2 is ~47 ohms - looks ok according to schematics.

author: edavid
author_rank: Super Contributor
timestamp: August 14, 2017, 08:37:24 pm
content: Quote from: andrejsstrumfs on August 14, 2017, 07:28:49 pmWhat happens if you disconnect the cable from P90 and connect a 47 ohm resistor there?

author: andrejsstrumfs
author_rank: Newbie
timestamp: August 14, 2017, 08:57:06 pm
content: Quote from: edavid on August 14, 2017, 08:37:24 pmSame thing - no signal. But i noticed that with the resistor or connector in place i get -0.3V DC there. But even with no resistor or connector in place the amplitude is too small - about 50mV. On ch1 same signal was ~0.3V

author: edavid
author_rank: Super Contributor
timestamp: August 14, 2017, 09:59:38 pm
content: Quote from: andrejsstrumfs on August 14, 2017, 08:57:06 pmI guess you should connect the same signal to ch1 and ch2 and compare stage by stage.

author: andrejsstrumfs
author_rank: Newbie
timestamp: August 15, 2017, 04:14:53 pm
content: Quote from: edavid on August 14, 2017, 09:59:38 pmThanks for help, turned out the problem was a tiny hair crack on pcb. Soldered and fixedAndrejs
Strange replacement for NiCds with caps and zeners (HP 3420B) - Page 1
Forum section: electronics / repair

author: perdrix
author_rank: Frequent Contributor
timestamp: August 14, 2017, 11:22:45 am
content: I just removed a couple of perf board circuits from inside an HP 3420B.The intention I am sure was to use these to control the voltages fed to the circuits after the NiCd batteries had been removed.The 24V supply has a 2200uF cap, a 22k resistor and a 1N5359 24V 5W zener all in parallelThe floating 12-0-12 supply has a 2200uF cap between the +/- 12V rails, and then a 12k resistor in parallel with a 1S3012A 1W zener between each rail and 0V.Now it has to be said that the drive circuits was designed to charge the battery packs so will be high impedance or current sources. Still I'm puzzled.Did whoever fitted these get confused and fit the resistors in parallel with the zeners when they should be in series, or it this correct?ThanksDave

author: bitseeker
author_rank: Super Contributor
timestamp: August 14, 2017, 09:18:40 pm
content: I'm not sure what the original intent of the add-on circuits was, but those sound like bleed resistors to empty the caps after the power is cut. Is the 24V supply unregulated, relying on the battery to smooth the power, hence the zener diodes?

author: perdrix
author_rank: Frequent Contributor
timestamp: August 15, 2017, 12:19:54 am
content: Both the 12-0-12 and 24V circuits are unregulated battery charging circuits (current source).Dave

author: edpalmer42
author_rank: Super Contributor
timestamp: August 15, 2017, 01:01:04 am
content: If nicds were removed, the voltage to any downstream circuitry would rise, possibly to a level that would result in problems due to the voltage rating of the components and/or power dissipation. The zener would clamp the source to an acceptable level at the expense of dissipating perhaps a significant amount of power.The resistor sounds like a bleed resistor, but I don't really see the point. It's unlikely that it was supposed to be in series. 22K in series would limit the current to about 1 ma.Ed

author: bitseeker
author_rank: Super Contributor
timestamp: August 15, 2017, 02:33:21 am
content: Quote from: perdrix on August 15, 2017, 12:19:54 amThanks for the confirmation. Yep, so bleed resistor, filtering cap and rudimentary voltage regulation (zener diode). As Ed said, the bleed resistor is odd. Usually you'd put that in for draining high voltage caps in a power supply.
Cleaning scope front ends?  - Page 1
Forum section: electronics / repair

author: cj555
author_rank: Contributor
timestamp: August 14, 2017, 06:13:43 pm
content: Hi everybody – I have a digital Tek scope that seems like it was in a dirty environment. When I got it there was a kind of oily gritty film covering the inside services, not real thick but definitely noticeable. I've cleaned it off most of the board, and that seems to of helped a couple of issues.But I seem to recall someone discussing on a video why you should be really careful and never even touch those sensitive components, oils from your finger etc. they may have any details or links about that? (Dave very well may have discussed it, or maybe it was Signal Path. Pretty sure it wasn't Mike though! He often doesn't seem to be as gentle with stuff :-). )Or recommendations on cleaning, leave alone, do it carefully but then assume I'd have to recalibrate, etc.?Thanks!

author: Karlo_Moharic
author_rank: Regular Contributor
timestamp: August 14, 2017, 08:50:52 pm
content: Use rubbing alcohol and Q-tips. Rub gently and let it dry good before plugin it into outlet

author: bd139
author_rank: Super Contributor
timestamp: August 14, 2017, 09:00:16 pm
content: As for why, Skin oils and other crap has a relatively low resistance compared to air so when it gets on high impedance areas it tends to cause all sorts of weird measurement errors.IPA recommended here too. I use one of the wife's horse hair paint brushes (new - don't tell her) and lint free cotton cloth.

author: JFJ
author_rank: Regular Contributor
timestamp: August 14, 2017, 09:59:31 pm
content: Quote from: cj555 on August 14, 2017, 06:13:43 pmThere are some useful tips about PCB rework, repair and cleaning, in an old HP Bench Briefs article:http://www.hparchive.com/Bench_Briefs/HP-Bench-Briefs-1982-07-10.pdfThe PCB cleaning part starts on page 8, but 'To Clean or Not To Clean' is briefly discussed on page 7.

author: bd139
author_rank: Super Contributor
timestamp: August 14, 2017, 11:02:01 pm
content: I think I actually read that once. Good reference!
HP 37732A Datacom Telecom Analyzer - Page 1
Forum section: electronics / repair

author: AllTheGearNoIdea
author_rank: Unknown
timestamp: August 14, 2017, 12:04:15 pm
content: HelloI recently bought a HP 37732A Datacom Telecom Analyzer. I was getting a corrupt RAM message at start up and removed the cover to investigate a replacement lithium battery. I did not dissemble it completely just removed it from the cover without removing any connectors or components. I then reassembled it and I have a replacement battery on order.Anyway when I switched on I then had a screen fault. It looks like the horizontal hold with the graphics scrolling sideways ways across the screen – no it’s not a CRT. I removed it from the case and tweaked all of the visible connectors and resembled it.I now have what looks like a bad column all the way down the screen about an inch wide. I have posted some pictures on my YT channel and one of my subscribers has comment that its missing some of the interlacing. I am not sure what screen technology its actual using and I’m assuming its some type of back lit LCD. Anyway I hoping some of you will be more familiar with this type of display than I am and can give me some advice regarding the failure mode I am experiencing.I am really hoping its some form of mechanical problem like a connector or IC that just need reseating as It would be unlucky if it has chosen this moment to go bang. I have the operators manual for the equipment but not the service guide and no circuit diagrams. I have googled but no joy.The equipment itself consist of a number of boards stacked on top of each other. The top board is obviously the power supply section so I assume this can be ignored. The next board down looks to be full of FPGAs and then there a few boards under that with I think the video board at the bottom of the stack. I’m going to separate the stack of boards later in the week to replace the lithium backup battery. So it’s likely will be able to tweak the connectors. I have had a prod around with the unit powered up but have not managed to correct the bad column.Anyway please let me know if you have any ideas. Link to my channel bellowThanks Chrishttps://youtu.be/is1YqxsTetE?t=30s
LCD TV (Sony) temporary dark shadows/cross in the center? - Page 1
Forum section: electronics / repair

author: onesixright
author_rank: Frequent Contributor
timestamp: August 11, 2017, 07:10:45 pm
content: Hi,I just noticed that exactly in the center there is a "cross like" dimmer/darker section. It pops up for a few seconds, then it disappears. If i change the channel its gone, when i switch back its there. As I said, it fine after some seconds.Is this any sign of somecatastrophicproblems in the near future? Or could that just be the signal?I'm using a external DVB-S2 tuner (via HDMI). The tuner of the TV is not used.Thanks!

author: BMack
author_rank: Regular Contributor
timestamp: August 14, 2017, 08:16:59 am
content: If the TV is "Full array" you could have a LED that's drifting out of spec. Does it have local dimming? If so turn it off and see if that changes anything.The only LEDs I see are TVs that have failed, normally it's something drawing excess current or a LED that has blown open...In those sets often there are LEDs that have drifted out of spec and do not light at the same rate as others(or ones that have shorted and do not light at all), they're not always the cause of failure but that's not to say they're not a future failure. As a reputable business, we change those LEDs as well so I cannot say for sure that they're an indication for future failure. Also, I have not heard or seen enough to say for sure that this is your problem.

author: onesixright
author_rank: Frequent Contributor
timestamp: August 14, 2017, 08:21:20 am
content: Thanks!I will make a picture of it next time it happens. It looks very weird, but since swapping the channels its disappears (and when swapping back its there). I would think its something with the signal.I guess: A picture is worth a thousand words

author: Smith
author_rank: Frequent Contributor
timestamp: August 14, 2017, 11:33:51 am
content: I had the same last week with something I recorded using my Samsung C7140B decoder. It came back a few times during the same recording. Switching to normal tv made it go away. I have never seen it again. It was in the Netherlands btw.

author: onesixright
author_rank: Frequent Contributor
timestamp: August 14, 2017, 11:37:11 am
content: Quote from: Smith on August 14, 2017, 11:33:51 amWell, i'm not living in Holland (anymore). But, it was via CanalDigitaal (dutch Satellite provider)
TDS460 Backplane Corrosion - Page 1
Forum section: electronics / repair

author: mcarberry
author_rank: Newbie
timestamp: August 13, 2017, 05:58:40 pm
content: I bought a TDS 460 a while ago non-working and took it home to found that it actually booted and occasionally passed all self-tests. However, it was flakey and I finally got around to taking it apart and figuring out what was wrong with it.There were no obvious signs of leaking caps or corrosion until I got to the backplane, where it appeared that all Marcon brand capacitors on it had given up the ghost. I removed all the parts on the board in the affected area and cleaned as much as I could with alcohol.As I cleaned, a significant amount of the solder resist came up and I can see in the area around C10, C11 and C7 where it looks like the corrosion is under the solder resist.I was planning to clean this and then cover the copper with an epoxy like this (https://www.digikey.com/product-detail/en/chemtronics/CW2500/CW2500-ND/1929217). Is this a good plan? Should I remove more of the solder resist around those capacitors before doing this?Thanks in advance!

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 14, 2017, 07:12:43 am
content: Hmm, make sure it's well cleaned (soak in water, alcohol), don't want that electrolyte going any farther. Chip away at the edges of the corroded areas to be sure you're just scraping at clean soldermask. I don't know about that epoxy specifically, but something to coat it is a good idea. If nothing else, tin it, and cover anything that needs to be covered with tape or lacquer; or use an epoxy like that.I had to replace all the little caps (on CPU, ACQ and HMI) in mine. Didn't notice any damage on the backplane, but it looks like I should expect needing to dig into it at some point...Tim

author: xwarp
author_rank: Frequent Contributor
timestamp: August 14, 2017, 08:45:49 am
content: Hit local drug store/walmart and buy some cheap fingernail polish.
HP 3456A: searching board mounts (clips) - Page 1
Forum section: electronics / repair

author: try
author_rank: Regular Contributor
timestamp: August 13, 2017, 02:32:24 pm
content: Is there any source available for the black clips as shown on the picture attached?

author: pelule
author_rank: Frequent Contributor
timestamp: August 13, 2017, 03:53:45 pm
content: I am not sure if the original parts are still offered on the market.But this may an option:https://www.southco.com/en-us/ny-wg?hid=7512/PeLuLe
Corsair H60 Hall Effect Sensor Repair - Page 1
Forum section: electronics / repair

author: DDock
author_rank: Contributor
timestamp: August 12, 2017, 01:36:05 am
content: I ended up getting this Corsair H60 second hand and it wasn't working. I tracked it down to a broken leg on the Hall Effect sensor. I am fairly new to the electronics repair scene and have basic to moderate knowledge. I am having trouble tracking down this sensor so I can get a new one. The first picture is the broken off sensor. The "nipple" side was sticking out the top of the board. The second is the board. Any help to try to identify the package type or part number would be awesome. I tried looking around on Mouser but didn't see anything close.On another note, I doubt there is a way but could there be a way to bypass the sensor? I highly doubt you can from what I have learned thus far. I'm guessing the controller is looking for some sort of input to know how to control the speed.Thank you for any help you guys can give.

author: SeanB
author_rank: Super Contributor
timestamp: August 12, 2017, 10:54:58 am
content: Grab an old FDD drive, there are 3 of those on the motor drive board that likely would solder in directly and work there.
METEX M-3650B need help - Page 1
Forum section: electronics / repair

author: YU7C
author_rank: Regular Contributor
timestamp: August 06, 2017, 05:04:30 pm
content: Hi,After few years collecting dust, I decided to repair my old METEX M-3650B from 1993.It seems that 7106 is broken, because it doesn't react on voltage which comes from divider. We will know a result after the chip is replaced.Also I didn't find voltage reference, despite it exist on the schematic (ICL8069)?Actually my main problem that i was a bit careless and during testing broke two wires between main and auxiliary boards which menage LCD for bargraph,...Does anybody know how to right way to connect two boards?

author: coromonadalix
author_rank: Super Contributor
timestamp: August 07, 2017, 11:09:52 am
content: you have to sniff where thoses 2 pins goes on each boards ... the schematic is available, and find where they link

author: YU7C
author_rank: Regular Contributor
timestamp: August 07, 2017, 01:31:35 pm
content: Unfortunately, I didn't find schematic of auxiliary board with M-8850.

author: ModemHead
author_rank: Frequent Contributor
timestamp: August 07, 2017, 04:13:04 pm
content: Perhaps the pictures in the following post will help.https://www.eevblog.com/forum/testgear/how-to-take-apart-voltcraftmetex-3650b/msg585927/#msg585927

author: YU7C
author_rank: Regular Contributor
timestamp: August 07, 2017, 04:35:39 pm
content: Yes, that helps! Thanks.Now waiting for 7106 chip.

author: YU7C
author_rank: Regular Contributor
timestamp: August 10, 2017, 05:21:48 pm
content: First, I had put UMC UM7106 which apparently should be compatible with ICL7106 but multimeter didn't work at all.Then I found original Intersil ICL7106 and it's live again. After short calibrating process with help of 8840A it's in function.Puzzle with UMC UM7106 remains. I found info that UM7106 has totally different function?
Agilent 54622a PulseWidth and ModeCoupling buttons not working - Page 1
Forum section: electronics / repair

author: BC7333
author_rank: Newbie
timestamp: August 10, 2017, 10:05:17 am
content: Hi all!have this used osci, self-tests and self calibration worked fine, battery ok and replaced carbon rubber conductors on several keypads, all work fine now except for PulseWidth trig and ModeCoupling. When powering on the LED for PulseWidth flashes so led is ok. Reset to default works fine. Also tried direct contacts with graphite leads on the circuit board without the rubber buttons all work fine except these two. Did some continuity checking and tested transistors and other components, all seems fine. Unfortunately can't find a schematic anywhere. Anyone know if a schematic is available somewhere or has one? If not, anyone have an idea where to continue looking for the problem? Any good vintage parts sources y'all know of? Would like to try another keypad board to see if that resolves the issue.Kind thanks for any assist!Brian

author: BC7333
author_rank: Newbie
timestamp: August 10, 2017, 10:22:00 am
content: Here are some picsPulse Width trig S35/S36 Mode Coupling S15/S16
Cubex Trio 3d Printer Repair - Page 1
Forum section: electronics / repair

author: Tumatauenga
author_rank: Newbie
timestamp: August 08, 2017, 06:58:08 am
content: So recently my older brother decided to buy himself a second hand 3d printer, the Cubex Trio by Cubify. The unit doesn't have an on/off switch, it has to be switched off at the wall. Well, my brother was too lazy to dig behind some boxes to unplug it from the wall and decided to tune it, while it was on, accidentally connected 2 pins on the top of the unit with an allen key and shorted the unit.Now when plugged in, the LED's on the unit turn on, but the backlight on the LCD display does not turn on and the display itself cannot be used. As such the entire unit can no longer be used. The LCD display is plugged into the Mainboard on the bottom of the unit. The pins that were shorted are at the top of the print head.We really need help figuring out how to fix this. We have a Fluke Multimeter to test it, but without knowing what to test we are up shit creek. Any help in this regard would be greatly appreciated. The attached pictures of the unit and the 2 boards.

author: DaJMasta
author_rank: Super Contributor
timestamp: August 08, 2017, 07:58:21 pm
content: A little hard to tell, is that a 5 pin or a 4 pin connector that was shorted? Do you know what it would connect to?As for starters, check power rails and check resistance on the pins of the connector. If you can find a ground somewhere in the system, check voltages on each pin and reference that to what should be there (why knowing what plugs in is important). While powered down, you can also measure resistance between each of the pins in the connector, if you find something that's near a short, the damaged part(s) are probably connected to those pins.If you find a power rail that is way under, you've probably damaged something in the power circuitry, so you want to see what is connected to it that could be the problem. I think it's unlikely that you just blew some protection part given where the connector is and that the rest of the unit reacted like that.
Please help me!Bricked Siglent SDS1062CM Oscilloscope! - Page 1
Forum section: electronics / repair

author: wenpaul
author_rank: Newbie
timestamp: May 29, 2016, 02:01:16 am
content: Hello guys.I got the siglent sds1062cm,after uploading the incorrect firmware. When I turn on the Oscilloscope , nothing is displayed only bright screen. USB does not work. I have a FLASH Programmer,and I also have a URAT and JATG?but i dont know how to doThese are the main board photos~~~Maybe no one has this oscilloscope .But I know the sds1062cm and other oscilloscope circuit are almost the same.Could you please provide some reference methods for me?Thank you !

author: tautech
author_rank: Super Contributor
timestamp: May 29, 2016, 02:24:43 am
content: Welcome to the forum.Your country flag shows you're in China but where ?Siglent are in NW Shenzhen and aren't hard to find.Have you flashed your DSO with CML firmware....I'm not sure if it's compatible with the older narrow screen CM models.Siglent are forum members here and I suggest you send them a PM for advice.https://www.eevblog.com/forum/profile/?u=83560

author: xrunner
author_rank: Super Contributor
timestamp: May 29, 2016, 02:31:09 am
content: He already posted this elsewhere ... be patient wenpaul!

author: wenpaul
author_rank: Newbie
timestamp: May 29, 2016, 02:33:00 am
content: Ok?thank you!I try to contact them

author: wenpaul
author_rank: Newbie
timestamp: May 29, 2016, 02:36:04 am
content: Quote from: xrunner on May 29, 2016, 02:31:09 amI'm sorry, I'll be patient. Thank you;D

author: tautech
author_rank: Super Contributor
timestamp: May 29, 2016, 02:37:49 am
content: Quote from: wenpaul on May 29, 2016, 02:33:00 amPlease let us know if you get a solution/fix/replacement.

author: wenpaul
author_rank: Newbie
timestamp: May 29, 2016, 02:39:28 am
content: Ok?No problem

author: xrunner
author_rank: Super Contributor
timestamp: May 29, 2016, 02:40:49 am
content: Quote from: wenpaul on May 29, 2016, 02:39:28 amYea you just need one thread and people will probably help you, just give it some time, that's all.

author: wenpaul
author_rank: Newbie
timestamp: May 29, 2016, 02:43:14 am
content: OK,sorry :-[Next time I will pay attention, this is my first time to send a post

author: tecnofreitas
author_rank: Newbie
timestamp: October 18, 2016, 07:34:20 pm
content: Hello friends! I have the same problem, what was the solution? Thank you!

author: konstiva
author_rank: Newbie
timestamp: August 08, 2017, 05:46:27 pm
content: Hi guys,can anybody share with me firmware for SDS1062CM. same situation.
Coffee machine power supply transformer - how to find a direct substitute? - Page 1
Forum section: electronics / repair

author: Lorenzo_1
author_rank: Regular Contributor
timestamp: August 07, 2017, 11:49:27 am
content: A friend's coffee machine stopped working (something of a disaster for him as he does like his coffee!). Fairly quickly located the problem - an open winding on the primary of the power supply transformer (photo attached). It's a simple 230V 50Hz to 12V 1.9VA transformer marked V30AJ-123P7. Doesn't seem special apart from being inherently short circuit proof. The whole board has several optical isolators built into it to isolate the control board from the 240V powering the heater element.Managed to find a datasheet (extract attached - the item's about halfway down the first table) and circuit diagram. Hoped to find an identical replacement unit but no joy locating an exact match for sale online. It looks like it could be substituted quite easily but better to source one with the same form factor/pins etc. Not sure if this is a pretty standard form or hard to get. Wondering if anyone here can point me to a likely source or recommend any pitfalls to look out for in trying to find a substitute. On the one hand, it's perhaps not worth the effort to track one down - but there is something rewarding about bringing appliances back to life rather than just turfing them and buying new. Perhaps easier to just buy a new power supply but wasteful if this one is repairable easily.

author: voltsandjolts
author_rank: Unknown
timestamp: August 07, 2017, 12:23:20 pm
content: Its not clear what the pin spacing is.Maybe this:uk.farnell.com/1689055

author: Lorenzo_1
author_rank: Regular Contributor
timestamp: August 07, 2017, 09:47:28 pm
content: That's perfect - thanks for the quick steer.Pin spacings are good. Will order it today and hopefully get the caffeine flowing again. My previous searches for replacement SMPS transformers took me into a lot of complex details and design issues, so I had expected this to be much the same. Nice to find it readily available and cheap to boot. Thanks again.Interesting to compare this machine with my own Rancilio coffee maker that just runs on 240V and relies on bulky manual switches but is dead simple to fix - no neat little button switches relying on 12V power and no 'fancy' IC control modules. Replacement power supply for this costs about half the price of a new machine - so with service agent fees it would likely make be just a throw-away item if you couldn't DIY it.
Broken TV (TEAC LEV3992FHD) - Page 1
Forum section: electronics / repair

author: Comic_Sans_MS
author_rank: Newbie
timestamp: December 04, 2016, 05:24:07 am
content: The TV powers on and shows the TEAC splash screen, then the power LED goes spastic and starts flashing green and red, then the TV restarts and does the same thing again and again...The main board is a TP.SIS231.P83, I cannot find a replacement on Aliexpress or Ebay. The Board also doesn't have visible damage like blown capacitors or burn marks.Does anyone have any ideas on what I should do to try and fix it. I have already unplugged the internal DVD player and speakers.

author: iamdarkyoshi
author_rank: Frequent Contributor
timestamp: December 04, 2016, 04:25:23 pm
content: I'd try checking the main electrolytic capacitors with one of these:http://www.ebay.com/itm/322304573638They are a lifesaver.And if you don't have a good soldering iron, get one of these:http://www.ebay.com/itm/381843202724I've got the more expensive 3 in 1 unit, and my original tip works like new after a year.

author: Comic_Sans_MS
author_rank: Newbie
timestamp: December 05, 2016, 02:28:48 am
content: Thank you. I will buy the transistor, diode tester and the soldering iron.I'll buy them when I get home.

author: Mike000000
author_rank: Newbie
timestamp: August 06, 2017, 05:55:48 am
content: Hi,did you have a good luck with it? i have the same problem.

author: difinity
author_rank: Newbie
timestamp: August 06, 2017, 10:13:19 am
content: Restarting at the splash screen is firmware. You'll need to remove the eeprom and program it externally.

author: BMack
author_rank: Regular Contributor
timestamp: August 07, 2017, 03:16:44 pm
content: I agree, it's an EEPROM problem.
RS232 link into HTM MX-700 flakey. Caps? - Page 1
Forum section: electronics / repair

author: Minok
author_rank: Newbie
timestamp: August 07, 2017, 04:00:19 am
content: I've hade this Home Theater Master MX-700 programmable universal remote control for 15 or so years. Served me well. Beauty is one can configure the buttons and macros in a PC application and upload it to the remote. Worked up till now. The past week in the middle is an upload ( hadn't done so in a year) the rs232 transmission failed. First thought was, the cable. So I tried the other remote with the same cable and that transmission works fine. So the cable and PC settings and software are fine. It's got to be the remote.Diagnosis time. Opened up the remote to look at the jack as the next thought was the 3 conductor 3.5mm aux jack used to connect to the serial cable had a contact spring inside just give up. So testing conductivity between the serial cable db9 connector end pins and the contact pads on the remote PCB itself (with cable plugged in) showed conductivity was solid. The db9 end of the cable pins were conducting to (and only to) the pads on the PCB of the remote.So now I'm wondering what's going on. As I try to initiate a PC to Remote upload it will fail, the work through a partial upload before failing, the fail then fail the partly work, through several retries. So the Rs232 signaling (3 conductor RX TX GND) is working some of the time but the signaling isn't stable at the PCB side.As I've seen on a variety of repair videos it's electrolytic capacitors that die of age and there are a few electrolytic caps on the board. Likely failure point for a remote powered by 6v of AA batter power over 15-18 years?The intermittent failure doesn't seem like a silicon problem. Or is that a real possibility?Looked for cold solder or obvious part damage but nothing visually sticking out.Attached is a photo of the PCB of the remote around the jack that brings in the serial data signal and the 3 conductors leading out of the jack into the PCB.Any advice ?
12V PSU Healed itself? - Page 1
Forum section: electronics / repair

author: mentaldemise
author_rank: Regular Contributor
timestamp: August 06, 2017, 04:42:44 am
content: I had a 3D Printer PSU go POP. I went to look and see if any caps were screwed and found they were all okay. Underneath the board it looks like there was a short. From what I can see one of the AC in lines to the bridge rectifier jumped to a MOV and blew the track off. The PSU and Printer both worked afterward. What are the chances that blowing the end of the track up fixed the issue?

author: mentaldemise
author_rank: Regular Contributor
timestamp: August 06, 2017, 05:15:09 am
content: Thanks. I'm pretty confused still as to what even happened. The printer wasn't printing at the time. I'm not sure why the track would extend so far past the bridge rectifier in the first place. The track that's missing was peeled back to touching the MOV. I assume it's a mov anyway.

author: mentaldemise
author_rank: Regular Contributor
timestamp: August 06, 2017, 05:19:57 am
content: I looked again. The part that AC jumped/shorted to is an NTC 5D-11, current limiting thermistor. :/

author: mentaldemise
author_rank: Regular Contributor
timestamp: August 06, 2017, 05:40:37 am
content: I'm not sure that's what happened. It looks like the 2 thermistors are connected to the negative output of the bridge rectifier and act as a "fuse" of sorts. It looks like one of the AC tracks actually touched one of the thermistors somehow. I didn't look at it before to know if there was a solder bridge there or a lead sticking out too far.

author: Armadillo
author_rank: Super Contributor
timestamp: August 06, 2017, 08:00:56 am
content: Did you move the 3D printer before it happened?

author: mentaldemise
author_rank: Regular Contributor
timestamp: August 06, 2017, 02:45:53 pm
content: No. I had printed like 20 minutes before hand. Was just sitting here and heard a pop, the UPS on the same circuit beeped but didn't trip, and then went to investigate. The 3D printer didn't even turn off or reset the USB connection. I'm wondering if the supply won't be fine if I clean all the carbon off and test it. There could have been a solder bridge under there or something that just exploded. These crappy supplies aren't good at trimming the leads on the bottom. :/
Asus PC power supply  - rectifier legs sort - Page 1
Forum section: electronics / repair

author: menash
author_rank: Contributor
timestamp: August 05, 2017, 04:47:36 pm
content: Hi, I have PC power supply that stop work. so I opened it and found the burn fuse and also burn sign between the rectifier chip. I checked the rectifier and it seems to be good (no short, and regular voltage drop).I attached an picture and you can actually see that there is small hole in the two middle legs which is the main AC input.Since the rectifier is good and I could not found any other defect component, so I replaced the fuse and connected the power supply again to the main with an 40W bulb for protection. the bulb light and I could actually see a spark go between the rectifier legs for second.I probably not going to use it again for my PC but for fun I will like to figure out what cause the problem and try to fix it.i will like to hear if yo have any idea.thank!!

author: coromonadalix
author_rank: Super Contributor
timestamp: August 06, 2017, 01:41:26 am
content: wow a sparking between the ac inputs pinsnever saw that one, is the pcb clean ??, nothing greasy conductive leaked caps ...The ac input ex: 95 to 240vac is rectified to dc by this rectifier bridge, and go to the primary pulse transformer 100khz to 200khz pulse frequency.Check for buldged caps or almost leaking ones ... the esr may have gone down.
Fixing a VORTEX 32G19 - Page 1
Forum section: electronics / repair

author: ealex
author_rank: Frequent Contributor
timestamp: August 12, 2017, 02:32:33 pm
content: HelloThis is a quick post about fixing a tv that had the HDMI connector melted off the main board.Got the TV as junk - so the only drive to fix it was my egoThe TV's id numbers are ( stickers on the main board / firmware, etc):C/N: PC07035P/N: CV028E_V5E0_01238D/N: 20070322X00005M/O:J03A117After opening the TV i got this:As you can see, the HDMI connector had a little accident. Looks like someone tried to weld the pins to the case. Half of the main board was covered in sooth and the panel's connector is partially melted.The first step was to clean up the board, to see the damaged area.After a lot of scrubbing, using the hot-air station and a lot of flux i ended up with:There where a lot of missing traces and deep burns inside the PCB. The protection on the HDMI lines was minimal, so it failled instantly when whatever hit the board happend.After cleaning the board and checking there are no shorts on the main 5V rail I tried powering it up from my bench power supply.I had to provide 5V and connect 5V_STBY to the 5V rail.Surprinsingly the board reacted to the "power on" button and the status led changed color.All on-board power supplies where working ok - proper voltages and no noise.The video processor IC that was connected to the HDMI and panel was getting verry hot and I could not see any activity on the LVDS or attached DRAM lines -> the conclusion was that the chip was dead.Also, there was the risk that whatever killed it also fried the panel, as it's directly attached.The main CPU was actually starting and trying to put stuff on screen. I could see data going out of it and I2C activity to it's settings EEPROM.After looking on ebay I found a board that seemed to be the same. I ended up buying it, knowing that the panel could be dead.The new board was the same hardware, but it had a completley different firmware on it.At least, it produces LVDS signals as soon as I connected it to 5V.After connecting it to the chassis it started the backlight and the panel.The different firmware meant that the pannel could not sync to the data stream => just random lines on the screen.Swapping just the settings EEPROM did not work - the new CPU just froze with the original EEPROM.I ended up swapping the old CPU as well(you can still see the flux)After that the new board was able to properly driver the panel -> I could see the OSD and the TV reacted to the remote.Next step - the power supply. This :became this:So after putting everything back together the TV works again. The only thing might need some work is the HDMI EDID eeprom - I might have to reflash it with proper data, but i'll check it once I get a hdmi cable=> got myself a big old LCD TV (CCFL based)Note: I really like the TS100 soldering iron. As the TV is very big I had to work on the floor -> TS100 + a repackaged 4S2P pack( with an added protection board) from an old notebook battery was a great combination. The cizel tip works great even on soldered heatsinks.
Help identifying Capacitor - Page 1
Forum section: electronics / repair

author: bji900
author_rank: Contributor
timestamp: August 04, 2017, 01:08:22 pm
content: All, Looking for capacitor. I have attached an image of the cap. I believe this is Tantilum, 10uF, 6.3V. But I do not recognize the logo on the part. It looks like AVX however the AVX logo does not have that little ball on top of the triangle. I sheared it when removing the pcb from the equipment. Probably not needed but if I can find a suitable replacement it would be great.
Metcal MX500P [SOLVED] - Page 1
Forum section: electronics / repair

author: Free_WiFi
author_rank: Regular Contributor
timestamp: July 26, 2017, 12:05:33 pm
content: I own the Metcal MX500P power supply.The model that i own is the 1 without the display :My trouble is: when im using the power supply with the hadler (MX-H1-AV) my hadler after some minutes is going to get hotter in the middle of the hadling zone.So im thinking to open my power supply and replace all capacitors,maybe this could fix my problem or maybe the problem is the hadler it's self ?

author: Armadillo
author_rank: Super Contributor
timestamp: July 26, 2017, 12:32:31 pm
content: Go to home depot get yourself the armaflex pipe insulation sleeve then sleeve a portion onto your soldering pencil and you won't feel the heat.

author: MosherIV
author_rank: Super Contributor
timestamp: July 26, 2017, 12:48:40 pm
content: QuoteSounds like the inductor in the handle is overheating. They are available as a replacement part.

author: Free_WiFi
author_rank: Regular Contributor
timestamp: July 26, 2017, 01:10:31 pm
content: Quote from: MosherIV on July 26, 2017, 12:48:40 pmDo you mean this one ?P.S this pic is not of my handler ,ive taken it from another post on eevbloghttps://www.eevblog.com/forum/projects/diy-metcal-13-56-mhz-rf-supply/msg438921/#msg438921

author: macboy
author_rank: Super Contributor
timestamp: July 26, 2017, 02:48:14 pm
content: Seems to me that your tip cartridge is defective. Try a different one and see if that helps. In contrast to typical soldering stations, the heating power of these is determined only by the tip, not by the base station, which just acts as a big RF power amp.

author: MosherIV
author_rank: Super Contributor
timestamp: July 26, 2017, 04:23:28 pm
content: QuoteI was wrong. Metcal do not do inductor cartridges for the MX500/5000 serie handles.They are only available for the older SP200 or the lower end PS900.Try want macboy said.

author: Free_WiFi
author_rank: Regular Contributor
timestamp: August 03, 2017, 11:48:30 am
content: Problem is solved !!!Basically my STTC-144 is defective .I tried to plug my brand new STTC 536 and the problem of the overheat on my hadler is gone

author: Free_WiFi
author_rank: Regular Contributor
timestamp: August 03, 2017, 12:03:18 pm
content: Defective tip :

author: macboy
author_rank: Super Contributor
timestamp: August 03, 2017, 02:02:58 pm
content: Glad to hear it.Note the STTC-536 is a low-temperature tip (nominally 500 degrees F, or 260 C). This is great for leaded solder with rosin based flux.

author: Free_WiFi
author_rank: Regular Contributor
timestamp: August 03, 2017, 03:02:18 pm
content: Quote from: macboy on August 03, 2017, 02:02:58 pmYes i know , i already got 1mm * 500g* of Cynel 60/40 soldering wireP.SSTTC-536 According to the metcal catalog (the number 5 stays for 302 C°)