This Web page last updated Jan 9 2021. To email me, see see my ordering Web page for my email addresses.
During Jan 2021, a colleage of mine in electronics and "making", put their "repair my vintage computers" situation out on a local "makers" email list, as I'll quote below. I was going to post a response, but it got awfully long. And what I wrote, was so generic and prescriptive, it would be overwhelming. And: it's really advice, where the question really was "can someone work this for or with me?". The answer is complicated: who wants to be told in detail why they got a "no"?
I decided to make a Web page of it, so I can just point to it and say, "here's how that kind of thing goes, friend". And of course, use the response again and let others find it by Web search. It is after all, my opinion. But based on experience and physical facts that others can affirm.
In a way that's the worst kind of unasked for advice. But finding it, or being directed to it, is less stressful, less personal.
I"d appreciate comments or more bits of detail. Mostly I'm trying to outline a situation and point to physical factors, and suggest options. Also: I'm not looking for a list of repair-services; not my job to route business or advertize others for free (sorry).
regards, Herb Johnson
Jan 2021: posted on a local makers email list: > I have three Amiga computers: "1000", 2000 & 3000. > The 1000 almost works and may only need tweaking. This was my first PC > and I will probably keep it. > > However the 2000 and the 3000 don't work and the reason is probably that > the batteries leaked onto the motherboard, ruining some of the > connections. > I wouldn't want these computers scrapped for parts, and I would like > some degree of involvement in their rebuilding, but someone else would > have to take charge. Once functional, I would want to see the > computer(s) put to use [by the owners or their maker organizations]
If these Amigas are like Apple Macs of the 80's and 90's, and many PC motherboards of the period, here's the likely problems. Here's my experiences which others in vintage computing can readily affirm.
0) Damage due to batteries is often catastrophic. Do not store electronic devices with batteries in place. Coin cells AKA watch batteries are much less risky but can produce damage. Details follow.
1) Surface-mount capacitors leak and fail open. The leakage creates high-resistance paths among the tiny leads. Open caps don't stop DC noise from IC's at work. These conditions produce intermittant and eventual persistant failure. Cure is to replace the caps, called "recapping" (look it up on the Web).
Here's a Mac PC board with cap leakage.
1a) Immediate & catatrophic capacitor failures. Tantalum capacitors fail short. That short creates a meltdown of the surrounding PC board under power. They even ignite, yes a flame like a candle. Certain AC capacitors fail with smoke and fumes. Repair depends on extent of damage. Here's a Web page about capacitor shorts.
2)Battery leakage is corrosive and gooey. These cause shorts and opens. Cure of cleaning doesn't restore broken connections.
3)Battery leakage produces hydrogen gas which is EXTREMELY corrosive. This causes rust in the broad area of the PC board and especially metals. Again, cleaning isn't sufficient.
4)Battery current for years at a time in the presence of moisture, produces copper rust (blue). this destroys copper traces and pins. Cleaning may not sufficient.
5)All kinds of things can leak and spread goo. This computer terminal had leakage from the CRT faceplate.
6)Power supplies fail. Simple ones can be repaired, post-1980 switching supplies may be repaired or replaced.
The fix for these things, begins with cleaning, then replacement of capacitors and rusted components, replacement of broken PC traces and connectors. But extensive rust or leakage is often a catastrophic failure which is not repairable as a practical matter. Computer boards of the late 80's and later, are multilayer and have traces inside the PCB, and through-holes that can also rust out - those are very difficult to find and repair. The fine traces on post-1980 PC boards are easily burned-out by a too-hot soldering iron, or by yanking traces out with components.
About Power supplies: Post 1980 electronics have switching power supplies, those often have big-cap failures and component failures. They vary in design and may be hard to figure out. But people fix them and they have common problems; there's books and Web pages just about repairs and repair-kits. Pre-1980 electronics have simple linear (big AC transformer) power supplies, those are simple and often need "capacitor reforming". I repaired a 1980 computer that way.
Much of my Web site is about repairing pre-1980 computers. A Web search for specific repairs or problems plus the words "site:retrotechnology.com" may be informative.
The diagnosis of these failures is mostly visual. Good clear focused photos of the boards in question, will show the depth of physical damage of leaky batteries. Strongly recommend: go outside on a bright but cloudy day, set camera/phone for "cloudy" or "sunny", take photos and avoid shadows. Sorry to be picky but fuzzy photos won't do it.
Another diagnostic is "board almost works, no battery leakage". That likely indicates problem 1), recapping and cleaning. That provides hope.
1980's, 90's and moreso 21st century electronics are challenging to repair. Surface mount components and multilayer boards require specific skills and tools, to engage in repairs of tiny components with tiny leads. The PC copper leads are also tiny, and they pass through multiple layers. One requires strong light and good vision, steady hands to do this work. Desoldering and soldering tools are specialized for this kind of work.
"Recapping" at the skilled and good-tools level, is work with and upon surface mount capacitors replaced with the same. Vacuum desoldering tools, soldering tools with multiple tips for purpose, fluxes, cleaners are among the tools. Skills are in the use of and experience with these. One may find YouTube videos for use, and Web pages describing tools and use.
Recapping at a less-skilled and tooled level, can be done by clipping out bad caps and soldering in conventional through hole caps with leads. This may be sufficient if the only failures are the capacitors. Again, videos and Web pages are findable. There's also books in recent years.
Many maker companies offer this kind of support and sell some of these products. Maker groups, and some vintage-computing groups, offer workshops and help each other (to a point).
In 2020, there's emerging services for "recapping", often by individuals offering flat-rate recapping of specific vintage computers. They are as good as the individuals themselves. Companies which do this work professionally, charge more than almost all vintage post 1980 computers are worth. Pre-1980 vintage computers are not often surface-mount, they are through-hole and repairable with 1980-class tools and skills.
Generally: individuals who can do this for themselves, are busy enough to NOT have time to do it for others, expecially for free. This crosses the line from "I'll help you with that" to "but I can't do it for you and you can't do it yourself".
Never ever EVER, store computer electronics with batteries in place. Coin cells (watch batteries) are acceptable to a point, but still cause copper corrosion in the presence of moisture. Leads and metals with currents on them for years will corrode.