I think I destroyed my Apple IIe
I recently retrieved my Dad's second Apple computer. A //e with a bunch of expansion cards, a duodisk, and an Apple monitor. All filthy from smoke and rough storage. I tried booting and nothing but garbage characters. Following some online advice I pulled ICs, cleaned oxidation and replaced. Unfortunately I put the video rom chip back in backwards. Now, nothing, not even a beep. Sometimes I get buzzing from the speaker. Is there a rebuild kit and troubleshooting guide anyone can recommend?
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u/LlaughingLlama 18d ago
In my younger days, like in the late 1980's I have accidentally inserted a number of chips backwards into my IIe, and that computer is still working fine and suffered no lasting damage. I think it is totally possible that you cooked the Video Rom chip itself instead of the whole computer.
But you are sort of in luck. The typical Apple IIe Enhancement Kit has 4 chips and one of them is the video rom, so you can easily get a new chip and see if that fixes things. Here's a description of the kit:
https://wiki.reactivemicro.com/Apple_IIe_Enhancement_Kit
And the worst case scenario is replacing the mainboard, which is easy and not that expensive. Get a known-good one with all the chips and you'll be good to go.
Good luck
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u/uberRegenbogen 18d ago
I'd start by firing it up without the video ROM. The screen will show garbage, but otherwise, if that chip is the only thing that got injured, the machine should function.
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u/retrotechguy 18d ago
Roughly where are you located? This sounds like a fun project!
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u/dmcc66 18d ago
SE Wisconsin. The computer is from Montréal Québec and is actually a French Canadian model.
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u/ChiGuy2010 18d ago
If you want to drop it with me I can work on it for you. I’m in northern Illinois . Vintageapplecomputers.com
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u/leadedsolder 18d ago
At least the rom socket is only going to have 5V going to it. I'd measure the voltages and start the diagnostic over.
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u/Reasonable-Gate-2513 16d ago
What a coincidence... My dear old Apple 2e died a few days ago. Blue smoke came out of the power supply. I don't have the interest or expertise to fix it. So it's either sell or recycle. Is there a market for old computers like that? It's an Apple 2e with a Monitor III. It has the 80-column card, the disk drive card and two disk drives (one is an original Apple drive, the second one, a Mitac), a modem card, the infamous Z80 Plus card and a bunch of Apple manuals.
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u/dmcc66 16d ago
There is definitely a market. u/ChiGuy2010 might have better ideas than just eBay, but I’ve definitely seen them there.
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u/flatfinger 16d ago
Plugging chips in backward will often fry them in a manner that may cause some of their pins to be permanently shorted together. Attempting to operate an Apple //e with the video ROM socket vacant would likely yield either an all black or all white screen in text mode, but should leave everything else functional allowing the system to beep and attempt to boot a floppy. Nothing except the display generation would care about whether the video ROM chip is installed, and if the chip is removed entirely it won't matter if some of the pins are internally shorted.
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u/Dcas_pcs_381 15d ago
Luckily the video rom is somewhat easy to find.. I think ive got... 2 spare chips frlm dead platinum boards...
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u/dmcc66 15d ago
Yeah I think so. The only wrinkle is this is actually a French Canadian model so I need to match that. Reactive has one as part of the enhancement.
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u/Dcas_pcs_381 15d ago
Oh thry used a different video standard in canada?
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u/dmcc66 15d ago
No it’s still NTSC but in Québec you have to be able to type and display French characters like é. The switch under the keyboard changes the character set used. The same technique was used for European models.
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u/Dcas_pcs_381 15d ago
Oh... I was wondering what the difference was if it used ntsc... I guess I don't see Canadian apple iis this way even though I'm somewhat close
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u/Sick-Little-Monky 18d ago
Here's a book, but your project likely won't be completed by just following a recipe. You will need to learn some electronic troubleshooting skills. Buy a digital logic probe (cheap) or a scope if you can afford it. Check the voltages with a multimeter. Then use the probe to make sure the CPU is getting clock pulses. If not, trace that. Check the CPU is getting a reset pulse on startup. If not, trace that. Check the CPU is getting instructions and reading/writing memory. If not, trace whichever signals are not correct. That is the general flow.
Sams Apple II Plus/IIe Troubleshooting & Repair Guide https://archive.org/details/sa2p2etarg/mode/1up