Save anything from the dump recently? - Page 1
Forum section: electronics / general

author: t_ryner
author_rank: Regular Contributor
timestamp: May 22, 2017, 01:09:19 am
content: Recently saved these TV boards from the dump. I love old CRT Boards so many reusable components inside, and the best part- Free!Here's the shared file-https://drive.google.com/open?id=0B0T3gelonW2VUEZIS1ZKLUNzVms(I only have a school computer, no editing software or file compression)

author: PointyOintment
author_rank: Frequent Contributor
timestamp: May 22, 2017, 01:20:05 am
content: A bunch of hard drive boards from the electronics recycling bin at my makerspace. They have good power MOSFETs on them, usually 3 dual ones to drive the motor, and occasionally some other ones for unknown purposes. I'm planning to use one for an LED stroboscope, and maybe I'll use some to drive some brushless motors again at some point (probably paralleled for bigger motors than the hard drives had, since I have lots of identical ones).

author: mmagin
author_rank: Frequent Contributor
timestamp: May 22, 2017, 01:45:30 am
content: I got some cute little (passive) speakers made by Boston Acoustics, about 3x4 inches in size in the recycling pile at work. Should be good for random test bench use where I need a 8 ohm speaker and maybe for building a signal tracer.

author: jonovid
author_rank: Super Contributor
timestamp: May 22, 2017, 02:49:36 am
content: another dumped 2D printer in the streetsame set of electronics, however after teardown, some components do get reused.inductors ,DC motors , plastic gears esc..

author: PointyOintment
author_rank: Frequent Contributor
timestamp: May 22, 2017, 06:06:07 am
content: Those current probes sure use a lot of current themselves. And did I read that right—you have an 800 kilowatt semiconductor tester!?

author: CJay
author_rank: Super Contributor
timestamp: May 22, 2017, 06:46:13 am
content: Mobility scooter which is going to be repurposed as a kart for my boy, mostly functional, dead batteries, missing most of the electronics and the bodywork has been vandalised but the wheels, chassis, motor and transaxle are all good.(Scrapped by the owner because a local mobility shop wanted more than a new scooter cost to replace the speed controller and batteries, I suspect there's a huge scam going on)

author: Berni
author_rank: Super Contributor
timestamp: May 22, 2017, 07:00:18 am
content: Quote from: CJay on May 22, 2017, 06:46:13 amWell that does sound an awful lot like the cost of repair on most consumer electronics like TVs. Repair costs so much that it makes more sense to just buy a new one and throw the old one in the dumpster. But hey sometimes there loss is our gain.

author: CJay
author_rank: Super Contributor
timestamp: May 22, 2017, 09:12:52 am
content: Quote from: Berni on May 22, 2017, 07:00:18 amThey're not a cheap consumer item though, they're really expensive to buy and from the stories I've heard from scooter users, they tend to be charged an awful lot of money for maintenance and repairs.What's worse in this case, I *think* the shop removed and kept the missing electronics making repair by anyone else so much more expensive.Hopefully a nice summer project for my boy and I, if the heavens align my daughter may even get interested.

author: TerraHertz
author_rank: Super Contributor
timestamp: May 22, 2017, 11:15:03 am
content: A bunch of reel to reel audio mag-tapes. Two cardboard boxes of them, found in a street toss. Someone had apparently stored them in a garage or something, then discovered they were colonized by little black ants. Sprayed the ants, then threw out the boxes of tape complete with dead ants.It turned out the ants were only in a few of the reel cases, and were easy to clean out with compressed air and a brush. Most of the reels were in tightly sealed inner containers, with no ants at all.I've wanted some 1/4" tape reels for a while, as I have a HP 3964A instrumentation tape recorder that uses these. Actually two units, one a bit damaged, the other OK. Purely a retro-tech restoration project for my museum.I would like to get a nice high-end consumer reel to reel audio tape deck though. One of those things that were out of my reach as a kid/teenager, when they were fashionable.

author: TerraHertz
author_rank: Super Contributor
timestamp: June 05, 2017, 03:12:28 am
content: Speaking of saving things from the dump, if you ever have an opportunity to rescue a really large plasma screen TV, here's some advice:DO NOT TAKE IT!Earlier this year I was given a very large one. Panasonic TH-50PH11AK, a bit over 1.2m diagonal screen. Hugely heavy.It was beyond repair (missing input cards) but did contain a large amount of boards with lots of power components, which was what I took it for. Also curiosity; I hadn't dissected a plasma screen before. Stripped it down, (http://everist.org/NobLog/20170224_summer_vacuum_odyssey.htm#cull) which left the problem of disposing of the actual screen.With LCD screens you can just smash the glass and put in the non-recycling roley bin. I'd had it in mind to do the same with this plasma screen. Big mistake.The construction is (from the front):* Sheet of protective glass. Which has a transparent conductive layer to prevent EMI emissions from the HV, HF plasma scanning lines.* Gap, about 1cm.* Front glass of the plasma screen.* Very small gap, under vacuum.* Back glass of the plasma screen, with raised ridges to maintain the gap, and the color phosphors.* Thin, tough double sided tape, adhering the glass to...* The aluminum backing plate, with reinforcing bars and mounting posts for all the electronics.So I had the front protective glass and the separate plasma assembly lying around for a few months, trying to figure out how to break them down. See the problem?The glass glued to the aluminum plate, makes a very difficult thing to cut up. Making it worse, the phosphors in CRTs are extremely poisonous. Obscure, secret compounds of rare earth elements, but google 'ccfl cut injuries'. For eg here:http://www.snopes.com/photos/medical/cfl.aspNote that Snopes and most other net articles get this *completely* wrong. They focus on the small amount of mercury in the CCFL bulb (not the cause of that necrotic disaster) but totally ignore the phosphors coated on the inside of the glass. Really, really stupid & ignorant omission. Yay Snopes /s.Anyway, not a good idea to get those powders in even a tiny cut. Or breathe them. Or leave bits of broken glass + phosphor lying on the ground, for pets to cut themselves on.First the front protective sheet. Should be easy to break, right?No. It turns out to be glass laminated front and back with something like kevlar. A hammer merely dents it. To cut it, takes a row of closely spaced dents then a large knife to saw through the plastic sheets and the powdered glass inside. Ugh. Pic1 was before I cut it up, after finding the merely folded piece was still too big to fit in the bin.Then the metal-glass laminate. I did all the glass-breaking of this under a large plastic bag, to stop glass chips flying all around. The front glass broke off easily, and was binned. That leaves the poisonous, solidly glued-on back sheet. It turns out to be extremely difficult to separate from the metal backing, even in small pieces. That double sided tape is *tough*. Trying to chisel it off, wearing full face mask, heavy gloves, and working with the chisel under a plastic sheet, it obviously wasn't going to be possible to strip the entire thing.But I couldn't just jigsaw the glass-plus-metal sheet, it would wreck the blade immediately. And I can't angle-grind it, because that will make and spread dust with the phosphor.The best solution I could think of was to chisel off the glass in minimal lines, then jig-saw the aluminum alone along the center of those lines after clearing the glass fragments. Which worked.Then the whole area got a very careful sweeping for glass fragments that had escaped the plastic sheeting, followed by obsessive vacuuming. And cleaning all the crap off the jigsaw and other tools.I won't be making that mistake again.

author: james_s
author_rank: Super Contributor
timestamp: June 05, 2017, 03:21:55 am
content: I don't think the phosphors are all that toxic. Older B&W tubes used a phosphor that contains cadmium and that is rather toxic, that phosphor was phased out for that reason.I rescued a 50" Toshiba LED LCD the other day, it mostly works but there's a dark band along the bottom. I suspect it has a bad LED like the other two big LCDs I have had.

author: helius
author_rank: Super Contributor
timestamp: June 05, 2017, 04:21:42 am
content: The phosphors are anticoagulants, so they have an effect similar to rat poison. Being adhered to potential sharp glass fragments makes them especially hazardous if you were to cut yourself.

author: Inverted18650
author_rank: Frequent Contributor
timestamp: June 05, 2017, 04:26:45 am
content: Quote from: TerraHertz on May 22, 2017, 11:15:03 amI have a friend that also has some 1/4" reel to reel audio tapes and claims one of them is actually historically significant. He says it was made using a Uhear recorder which has a adjustable speed setting. Have you heard of this brand or know where I can find one? If the Uhear is not available, can you recommended another adjustable speed player? Thank you.

author: edpalmer42
author_rank: Super Contributor
timestamp: June 05, 2017, 04:28:56 am
content: Quote from: TerraHertz on May 22, 2017, 11:15:03 amAre those audio tapes or data tapes? I don't know much about tapes, but I thought that they were different. Specifically, audio tapes are optimized for recording varying levels (i.e. analog) while data tapes are digital. Also, some old tapes degrade and the oxide starts to flake off the base. Google the specific tape brands that you've got to find out if your tapes fall in that category. You don't want to use them in your HP drive if they're going to pollute it with a cloud of oxide.Ed

author: helius
author_rank: Super Contributor
timestamp: June 05, 2017, 05:06:15 am
content: Quote from: Inverted18650 on June 05, 2017, 04:26:45 amThat'sUher: it is a German brand. The only reason I can think of that's historically significant is that it was the brand of recorderused by President Nixon to erase the most incriminating detailsfrom his secret tapes.Multiple speed settings were a common feature on 1/4" decks, under the theory that users would record different types of material and use the higher speeds for higher quality music. Frequency response gets better with higher tape speeds, with 15 and 30 IPS (inches/sec) being used for master recordings, and lower speeds for home copies and radio programs. Fine speed control was also common, to match the actual recorded speed so that music sounds properly tuned.

author: Brumby
author_rank: Unknown
timestamp: June 05, 2017, 05:15:20 am
content: Quote from: TerraHertz on May 22, 2017, 11:15:03 amI know exactly how you feel.When I was a lad, I collected several leaflets of the various model of Sony tape recorders available at the time. I remember they were a single sheet about A6 in size and predominantly orange in colour. I think there were a couple of dozen models all up. Never had the funds to buy one.Eventually I picked up an old AKAI with solenoid control and 10" reel capacity. One channel didn't work .... and I have yet to get it on my workbench to fix it up!

author: helius
author_rank: Super Contributor
timestamp: June 05, 2017, 05:33:42 am
content: Quote from: edpalmer42 on June 05, 2017, 04:28:56 amMagnetic tape has been used for computer data storage since the early 1950s to the present, so it has many more forms than audio tape, mostly obsolete apart from some lo-fi music studios. The open-reel data tapes were an ISO standard and looked largely the same for decades, with a plastic band that snaps into place around the perimeter to keep the tape from falling out. They are all 1/2 inch width, but could be recorded in many formats not compatible with all drives.Reel-to-reel audio tapes look totally different and are mostly 1/4 inch in width. Some wider machines only for studio use were 1" or 2" with dozens of tracks; the normal consumer recorders were always 1/4" and quarter-track (two heads for stereo, with space for another two tracks when the tape is flipped). The reels lack the plastic locking hub ring that is used on data reels for write protection, and are either plastic or metal with radial cutouts—a feature never seen on data reels.

author: Sonny_Jim
author_rank: Unknown
timestamp: June 05, 2017, 05:44:05 am
content: Found a working Gameboy pocket just sat out for hard rubbish. Don't mind if I do!

author: ed_reardon
author_rank: Regular Contributor
timestamp: June 05, 2017, 06:47:51 am
content: Not quite the dump, but a very good condition 'Beats Pill v2.0' Bluetooth speaker (replaced snapped-off micro-USB connector) - came in a mint retail box too with an unsued charger and unopened instruction manual.A Samsung LCD TV with a failed T-CON board that's about to yield lots of lovely odds and ends for the junk box.A inoperative TI-82 graphical calculator, looks like it's had a major battery leak but I'll open it up and see what I can do. Zilog Z80 anybody?Cheers,Ed

author: German_EE
author_rank: Super Contributor
timestamp: June 05, 2017, 11:11:11 am
content: Three PCBs from a scrap unit sat outside a factory. All of the ICs were in sockets and the collection included sixty (60) dual opto couplers and some useful 60V 1.5A high side switches with CMOS inputs. I might salvage the turned pin sockets as well but unsoldering them will be a boring job

author: HackedFridgeMagnet
author_rank: Super Contributor
timestamp: June 05, 2017, 01:47:45 pm
content: I sometimes save boards that have useful components on them. But don't desolder anything, just put it in a big box till you need a particular part it then desolder.

author: FireFlower
author_rank: Regular Contributor
timestamp: June 05, 2017, 03:30:41 pm
content: Lets raise the bar a bit...One is almost fully intact, just a bit spare parts shopping and one working Mantis and other one might become fully working with a bit spare parts bought.

author: GreyWoolfe
author_rank: Unknown
timestamp: June 05, 2017, 06:15:31 pm
content: Damn, fireflower. I couldn't get that kind of luck even if I gave the luck fairy all the money I have.

author: TerraHertz
author_rank: Super Contributor
timestamp: June 06, 2017, 09:43:36 am
content: Quote from: james_s on June 05, 2017, 03:21:55 amLarge screen LCDs mostly use a lot of very thin glass fluorescent tubes in parallel behind the diffuser sheets. Your dark band is probably one of them dead or broken. They are clip-in, if you can find one the same size... Good luck getting the thing apart to reach them, keeping the multi-layer diffuser sheets in the right order and totally dust-free, then all back together.Having pulled a few large LCDs apart, I have a length of fat PVC pipe full of those tubes. Not sure what I might ever use them for.Quote from: edpalmer42 on June 05, 2017, 04:28:56 amThey are 1/4" audio tapes. All with band/song lists. Would be interesting to play some of them, to see if the quality has degraded or not.The HP instrumentation tape recorder uses analog mode, recording 4 tracks of FM-encoded analog channels.I also have a couple of HP 800BPI data tape units, but getting them going would require some kind of software controller, since they are dumb minicomputer peripherals.

author: Electro Detective
author_rank: Super Contributor
timestamp: June 06, 2017, 10:23:27 am
content: Dumpsters here are full of builders waste covered in rained on plaster dust,sticky soft drink and stinking suss take out food, rooted printers and broken office crap.And that's the good stuffLUCKY DAY if a passer by can score a clean piece of off-cut wood or ripped out electrical cabling with flexible sheathing still attachedCheapskate office refurbs and night time dumpster vultures herewhat's this world coming to?

author: lowimpedance
author_rank: Super Contributor
timestamp: June 06, 2017, 12:31:08 pm
content: Quote from: Electro Detective on June 06, 2017, 10:23:27 am......... there's one of those right now at work, and the only thing that caught the eye was an industrial size broom with a broken handle.

author: james_s
author_rank: Super Contributor
timestamp: June 06, 2017, 03:23:48 pm
content: Quote from: TerraHertz on June 06, 2017, 09:43:36 amNot anymore they don't, I don't think anyone is making CCFL backlit LCD TVs anymore. This is a 2 year old LED LCD, it's an edgelit display that uses a strip of high power LEDs, the whole TV is about half an inch thick with a slight bulge near the base where the electronics are. I've repaired two other LED LCD sets that had bad LEDs, one is a 42" edgelit and the other 60" backlit. You're not kidding about it being a pain to take them apart, I ended up having to tear them down twice because I had nowhere to put the pieces while I waited for replacement LEDs to arrive. I did get them both back together and working though.

author: Electro Detective
author_rank: Super Contributor
timestamp: June 06, 2017, 11:01:23 pm
content: Quote from: lowimpedance on June 06, 2017, 12:31:08 pmThat's like winning Tattslotto for dumpster freebie hopers here

author: WZOLL
author_rank: Regular Contributor
timestamp: June 08, 2017, 04:01:27 am
content: Found some police radar guns and a very cool metal police briefcase radio that looks suspiciously like a bomb during a recycling day I volunteered for. Also picked up some ceiling mounted cctv cameras, vintage hi-hi recievers and tape decks, and a working NES which I sold on Ebay. If your community has an annual recycling day, the coordinators will usually let you save some things people drop off if you help out.

author: james_s
author_rank: Super Contributor
timestamp: June 08, 2017, 07:19:36 am
content: They really ought to encourage anyone to save anything they can use. The most efficient form of recycling by far is reuse. Most of those recycling events strike me as incredibly wasteful.

author: P90
author_rank: Frequent Contributor
timestamp: June 08, 2017, 08:29:24 am
content: I got a big juicy Dell top-of-the-line network laser printer they were going to dump at my brother's office. It had an error code that could not be cleared. I found a bad microswitch for the paper door, and the solution is normally to purchase the replacement pcb. I scrounged through my parts and replaced the switch. Works like new. LOL.

author: PointyOintment
author_rank: Frequent Contributor
timestamp: June 08, 2017, 10:04:42 am
content: Quote from: WZOLL on June 08, 2017, 04:01:27 amQuote from: james_s on June 08, 2017, 07:19:36 amWhere I live, I've heard those events are run specifically to get stuff off the used market, to force people to buy more new stuff. They won't let you take anything that's been dropped off, so I guess you'd have to intercept people on the way there and explain the whole thing to each of them.

author: P90
author_rank: Frequent Contributor
timestamp: June 08, 2017, 10:16:19 am
content: Quote from: PointyOintment on June 08, 2017, 10:04:42 amYup, even the recycling center drop off near me won't let people take anything. I see so many nice recent Samsing monitors, and tv's, etc., probably just need a few caps to get working...It's a shame to waste. RoHS my ass...

author: jonovid
author_rank: Super Contributor
timestamp: June 08, 2017, 11:25:02 am
content: Quote from: P90 on June 08, 2017, 10:16:19 amthere is this electronics drop off bin at shopping mall near me ,they may not like people taking anything but,I do help by recycling for them.got this old 90s printer.board has two full H-bridge driver PBL3717A dip chips on it with mico's & ram.large US made Buehler DC motor with with rotary encoder on the end , and stepper motor, lots of plastic gears in this old 90s printer.

author: P90
author_rank: Frequent Contributor
timestamp: June 08, 2017, 12:02:55 pm
content: Quote from: jonovid on June 08, 2017, 11:25:02 amHelp me to help you, sort of thinking...

author: jonovid
author_rank: Super Contributor
timestamp: June 08, 2017, 07:00:37 pm
content: Quote from: P90 on June 08, 2017, 12:02:55 pmas to say -no one is going to mess with me, over what is seen as worthless junk . like maybe I am helping by reducing the size of a pile of garbage. as the bin is in a public place .

author: james_s
author_rank: Super Contributor
timestamp: June 08, 2017, 09:03:01 pm
content: Quote from: PointyOintment on June 08, 2017, 10:04:42 amIt would be interesting to just help yourself and see what they say, I mean are they going to arrest you for "stealing" items that are being dropped off as waste? Seems like it might be a good opportunity to go to the news media and point out the irony and listen to whatever BS excuses they have. Probably the old "safety" boogeyman.

author: jonovid
author_rank: Super Contributor
timestamp: June 11, 2017, 11:53:02 am
content: Quote from: james_s on June 08, 2017, 09:03:01 pminteresting to just help yourself and see what they say, I mean are they going to arrest you forthat's what I doopportunity to go to the news media? the OLD news media?why bother .

author: X
author_rank: Regular Contributor
timestamp: June 11, 2017, 10:21:53 pm
content: I recently scored over 20 toroids, they look like 160VA ones.Also managed to extract dozens of 10000uF 50V and 63V caps, tri-colour LEDs (red/green/amber) and 24V (coil) DPDT relays from bits of old gear that was destined for the dump.Now all I need is a huge puck package SCR and some copper bar stock.Also a nice big AF oscillator that strangely is still within spec.

author: johnh
author_rank: Regular Contributor
timestamp: June 11, 2017, 11:31:46 pm
content: 4 power supplies from some Radware equipment that was being tossedFrom each power supply2 IRFP260N mosfet MBR6045W Schottky rectifier, numerous torroids, rubycon 80V 2200uf cap and various chemi-con capsSmall folding handle, 40x40mm fanCPU heatsink from some other equipmentand 2 Power supplies from an old Sun Storage ArrayMight have the basic parts for DIY load

author: CJay
author_rank: Super Contributor
timestamp: June 12, 2017, 09:35:13 am
content: Quote from: jonovid on June 11, 2017, 11:53:02 amLudicrous as it sounds, people have been prosecuted for theft for taking things from bins, skips, recycling and municipal sites, in the UK you *have* to have permission to remove things from the company who own the disposal facility or it's theft.If it's a municipal dump then you need what's called a licence to extract and some local authorities will not issue them, breaks my heart to see some of the kit in the local dump electrical recycling skips, I've seen all sorts of things crushed that should have been resold or at least re-used instead.

author: P90
author_rank: Frequent Contributor
timestamp: June 12, 2017, 10:57:03 am
content: Quote from: CJay on June 12, 2017, 09:35:13 ammakes you wonder why they don't give these working equipment to kids and families in poor developing countries, rather than destroying them. I know some will say shipping costs etc., but you can always find a solution. Greedy heartless giant corporations...

author: X
author_rank: Regular Contributor
timestamp: June 12, 2017, 11:08:29 am
content: Quote from: P90 on June 12, 2017, 10:57:03 amPerhaps that equipment is not edible enough.

author: jonovid
author_rank: Super Contributor
timestamp: June 12, 2017, 11:09:25 am
content: Quote from: P90 on June 12, 2017, 10:57:03 amsadly this may have something to do with why the brexit referendum and thousands of needless regulations made by the european union HQ in brussels.

author: CJay
author_rank: Super Contributor
timestamp: June 12, 2017, 11:31:30 am
content: Quote from: jonovid on June 12, 2017, 11:09:25 amNah, it's bugger all to do with the EU (though I'm sure you'd find plenty who will insist it is) or you'd not be able to get the 'licence to extract' in any borough, it just seems that every rule or regulation enacted and enforced by some petty little jobsworth is blamed on the EU.There are individuals and community projects which have that licence in some areas, some of the community ones train people to repair/refurb equipment and are self funded by the sale of the recycled items.

author: jonovid
author_rank: Super Contributor
timestamp: June 12, 2017, 01:30:44 pm
content: Quote from: CJay on June 12, 2017, 11:31:30 amdumpster diving is legal in Australia see Dave's video's- taking dumped electronics from a community bin is a bit vague.it is more about not making a mess by the bin. only taking what you need.as to say - one item a week is OK. no mess by the bin.some company's do not like used or repaired products competing for new products sales. true of large electrical goods.

author: CJay
author_rank: Super Contributor
timestamp: June 12, 2017, 03:53:18 pm
content: Quote from: jonovid on June 12, 2017, 01:30:44 pmI would much prefer it if that was the case here, but:http://www.bbc.co.uk/news/magazine-13037808TBH, I'd be surprised if something very similar didn't apply there too but it's really down to the 'owner' of the items and the owner of the bins/disposal facility to make a complaint to the police, they'd have to be absolute sh**bags to do so.

author: aargee
author_rank: Frequent Contributor
timestamp: June 13, 2017, 06:37:05 am
content: Taking "e-waste" or electrical items from charity bins is doing them a favour here in Aus. as it is all invariably dumped.I'm pretty sure that none of the charities re-sell electrical gear due to the cost of making sure it's safe to do so - everything has to be tested to the equivalent of a test and tag (them's the rules apparently).I can't vouch for it being a 'good look' when you do so.

author: CJay
author_rank: Super Contributor
timestamp: June 13, 2017, 07:14:39 am
content: Quote from: aargee on June 13, 2017, 06:37:05 amSome of the charities realised a couple of years ago that they were refusing or dumping a considerable amount of potential revenue so they (British Heart Foundation being one) now safety test, clean and sell electrical appliances, I know of one BHF shop that even does minor repairs though I suspect that's more to do with one employee than being policy.I'm all for it, it's a terrible waste to have to landfill it all and if you can buy safe second hand electrical goods at bargain prices then it's a benefit to those of us who don't mind second hand though I'd rather do the cleaning and refurb myself...

author: TerraHertz
author_rank: Super Contributor
timestamp: June 17, 2017, 06:54:08 am
content: Well, not *today*. More like 10 years ago. A pile of 46 identical boards I saved from the dumpster at work. They've been sitting in a box in the loft since. The ICs are all in sockets and today this box reached to the top of my strip-it queue.There's a story to these boards. But first, see if anyone can spot the glaringly obvious design flaw in the one pictured. The boards are all the same, and there are *many* design faults besides the visually obvious one. No it's not the removed battery, or the few unmounted parts.PS: No I didn't design this. I had to design the replacement.

author: SeanB
author_rank: Super Contributor
timestamp: June 17, 2017, 10:11:33 am
content: Are you talking of the very poor supply rail decoupling, the use of 16 bit ISA when it looks like it was only an 8 bit use, or the QFP devices that were pretty much guaranteed to be running hot and working their way out of the holders.

author: Cyberdragon
author_rank: Super Contributor
timestamp: June 17, 2017, 01:32:44 pm
content: I think he's refferring to the fact that despite barely using any of the edge connectors, there are several header connectors. What dummy routed that trace across there...EDIT: How many layers? Also, what bad decoupling? I see lots of little blue caps, also this is low speed, none of this modern RF speed rubbish.

author: TerraHertz
author_rank: Super Contributor
timestamp: June 17, 2017, 03:05:13 pm
content: Quote from: SeanB on June 17, 2017, 10:11:33 amThe 'decoupling.' Those "little blue caps" are 0.1uF polyester. *Someone* didn't understand the differences between polyester and ceramic caps, for decoupling. He also didn't know about not feeding TTL outputs into 74HC inputs, and most disastrously, had no idea that one shouldn't pass unbuffered logic outputs (and the logic ground) straight to unshielded cables going off board, to other devices in the upright pokie cabinet. Which players often like to jigger with piezo spark lighters, and whatever.There were other problems too, but I'd have to dig out my notes. If I even still have them. Oh, one was, the CMOS battery-backed RAM (which holds critical data) wasn't adequately protected from unexpected power downs.The board went into production and was hopelessly unreliable in the field. This happened because no one did any peer design review, management had no idea, the machine testers didn't bother to act like bastard players, and there weren't any lift motors etc near the testing area.Redesigning a stupid ISA-based IO board, because someone else did a crappy job, wasn't much fun. Pic of replacement board. 4-layer, but most importantly fully isolated I/O signals and ground. This one was reliable.

author: Cyberdragon
author_rank: Super Contributor
timestamp: June 17, 2017, 05:37:46 pm
content: Much better routing...wait...THAT CHIP IS SMALLER THAN IT'S SOCKET!DANGER...OCD OVERLOAD!BRAIN =

author: SeanB
author_rank: Super Contributor
timestamp: June 17, 2017, 05:51:51 pm
content: VESA bus, and I was thinking for a moment you had used a Ramified Dallas socket for the ROM as well. Must have been around 5 times as fast as the one it replaced as well, and with 16 times the performance to boot, along with having usable memory for both battery backed ( and RTC as well) and ROM store.I guess this was for controlling a whole row of game machines, so you could have a collective jackpot as well as setting payout probabilities on the fly, plus incorporating payment processing for coin, note and magstripe cards.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: June 17, 2017, 06:19:30 pm
content: Quote from: TerraHertz on May 22, 2017, 11:15:03 amThink twice about that. I have a Pioneer RT-909 and a TEAC X-3. Reel to reels in general are electromechanical nightmares, and if the heads are finished you have almost no chance to get that fixed on a reasonable budget.But fashion is cyclical, there's a new café down my street that has a RT-909 as a display piece! I have to go ask the manager if it works, and if he'd want to trade.I made the mistake of getting mine "repaired". The guy lapped the heads, which is a fatal mistake with Pioneer heads. The sound is unlistenable now.No to mention all the mechanical traps like the damper arms which need the correct fluid in them to do their job, the cosmetic covers over the rubber rollers, getting a new belt... etc.Everything has to be just so in order to work.Now with the weak Canadian dollar the machine I think is worth having is out of reach for me...

author: TerraHertz
author_rank: Super Contributor
timestamp: June 17, 2017, 09:16:51 pm
content: Quote from: SeanB on June 17, 2017, 05:51:51 pmHa ha, fair guess but no. That's not VESA, the extra edge connector is just all the I/O lines. We did a custom motherboard (my co-worker did most of that, the old friend who is now dying of liver cancer.) The board is still 8-bit ISA, though we did have PCI slots.That backwards S shaped line of components is the ground isolation line, with a gap between the external and internal ground planes. Optos etc straddle it.Quote from: Alex Eisenhut on June 17, 2017, 06:19:30 pmYeah, in general I know they are a pain. Though I've had no experience with specific models. Cassette tape decks and VHS players are bad enough. When I say "I would like to get one" I mean one with the head in good condition, and for which new rubber rollers etc are available. Ideally with direct motor drive of the reels and capstan, so no rubber belts.Hence my not having one yet.Quote from: Cyberdragon on June 17, 2017, 05:37:46 pmHaven't you seen that done before? EPROM pinouts allow for that - with a jumper to provide Vcc or A12 to one pin, can use 28 or 32 pin EPROMs.

author: Rémi
author_rank: Regular Contributor
timestamp: June 21, 2017, 08:01:15 pm
content: I saved 3 boards today. 2 x AD581 on them and lots of IC.Time to use the desoldering wick.