Apple Lisa 2/5 Restoration help please

[Courtney Louise]

Hi guys.

I recently acquired an Apple Lisa 2/5 that did absolutely nothing on first power up. I removed the batteries and cleaned every contact and recapped the I/O board and then got a beep. I have recapped as many of the electrolytic as I can and cleaned all of the edge connectors on the motherboard however I just get garbage on the screen. Not stripes but Hi-res garbage. This is supposed to be down to the memory board, first 16k I think, however I have 2 mem boards and I have tried them in both slots independently of each other and still get the same..

I have no access to any known good spare boards as Lisa's are ridiculously rare here in the UK to the point It's the only one I have seen since 1984.

Please help if you can or if you have any known working spare boards I can test mine with, I would happily pay a deposit for a loan panel...

Regards

Courtney

 

[lroop]

Hi guys.

I recently acquired an Apple Lisa 2/5 that did absolutely nothing on first power up. I removed the batteries and cleaned every contact and recapped the I/O board and then got a beep. I have recapped as many of the electrolytic as I can and cleaned all of the edge connectors on the motherboard however I just get garbage on the screen. Not stripes but Hi-res garbage. This is supposed to be down to the memory board, first 16k I think, however I have 2 mem boards and I have tried them in both slots independently of each other and still get the same..

I have no access to any known good spare boards as Lisa's are ridiculously rare here in the UK to the point It's the only one I have seen since 1984.

Please help if you can or if you have any known working spare boards I can test mine with, I would happily pay a deposit for a loan panel...

Regards

Courtney

Garbage on screen could also potentially be caused by the CPU not coming out of reset, bad ROMs, etc. causing the boot process to not start at all, or not get far enough to put something meaningful in the video frame buffer. If no more traces look obviously bad, you might try re-seating socketed ICs since it's possible that gases released by the deteriorating batteries caused corrosion leading to poor contact on socketed chips. Have you checked for any bad caps, dirty traces, etc. on the CPU board? Also, is the beep a constant beep, or does it stop beeping at some point? A constant beep that never stops could just be junk data coming up in the shift register that drives the audio, but if the machine beeps once and stops that would indicate at least some signs of life.

 

[Courtney Louise]

I finally got a replacement memory board and now I get 2 beeps and garbage. I have traced as many pins as I can and everything seems fine

Garbage on screen could also potentially be caused by the CPU not coming out of reset, bad ROMs, etc. causing the boot process to not start at all, or not get far enough to put something meaningful in the video frame buffer. If no more traces look obviously bad, you might try re-seating socketed ICs since it's possible that gases released by the deteriorating batteries caused corrosion leading to poor contact on socketed chips. Have you checked for any bad caps, dirty traces, etc. on the CPU board? Also, is the beep a constant beep, or does it stop beeping at some point? A constant beep that never stops could just be junk data coming up in the shift register that drives the audio, but if the machine beeps once and stops that would indicate at least some signs of life.

 

[lroop]

Sorry it took so long to reply to you. I'm inclined to guess that trash on screen and beeps is probably an I/O board issue, especially since you mentioned batteries. You might want to start looking for trace/pin damage near where the batteries used to be, and if possible use an ohmmeter to check the traces. Checking all the power supply voltages (the power connector for the hard drive is one good place to do this) would also be a good idea, especially if you find somebody who can swap parts (which would be the best way to identify at least which board is the problem).

 

[Chromedome45]

Something to try. May not work but turn system on and let it do it's thing. Now manually push the reset button on the back panel and see if that helps any. Report back to this thread. Assuming your still trying to get this Lisa up and running.

 

[james_w]

Hi Courtney

I've recently acquired a semi-working pair of Lisas - one 2/5 and one 2/10. I'm in London and happy to help if I can in some way, although I have no idea which boards in mine are good or bad yet.

 

[Chromedome45]

Good luck James hopefully you can get 1 going. Best place to start on them is the power supply. Look for bulging capacitors and replace.

I know that on my Lisa it would not startup until I hit the reset button on the back. Turns out that there is a 2.2uF Capacitor that can get leaky and should be replaced. I think it is the reset pulse buffer cap. I replaced that cap on mine and now boots fine. Just an idea. And something to consider replacing as well.

 

[james_w]

Thanks, yeah looks like the PSU in the 2/10 is definitely the culprit - there's some really big, and very bulging, caps in there!

Doesn't look all that easy to get the board out to disassemble and replace - any tips?

 

[Chromedome45]

Which type of power supply do you have james? there were 2 the original or what they call a 1.2 amp and there was the Data Power 1.8 amp.

If you have the original remove the screws that hold on the upper lid.

Look inside there should be about 8 to 10 metal screws in there.

The tricky part is near the big transformer you have 2 triacs near the bottom edge of the big transformer that are held in by a nylon screw with a metal top. Use a small flat blade screw driver to remove those.

After that is done board should lift out. May have to pull out at an angle.

Then desolder the 6 2200uF 16V capacitors in that area. They are usually bad. Had a couple in mine where one lead was still stuck to the board! So it separated from the main body... Cheap parts in there. Install replacement capacitors. I use Nichicon but any brand should work.

Hope this helps.

 

[james_w]

Which type of power supply do you have james? there were 2 the original or what they call a 1.2 amp and there was the Data Power 1.8 amp.

If you have the original remove the screws that hold on the upper lid.

Look inside there should be about 8 to 10 metal screws in there.

The tricky part is near the big transformer you have 2 triacs near the bottom edge of the big transformer that are held in by a nylon screw with a metal top. Use a small flat blade screw driver to remove those.

After that is done board should lift out. May have to pull out at an angle.

Then desolder the 6 2200uF 16V capacitors in that area. They are usually bad. Had a couple in mine where one lead was still stuck to the board! So it separated from the main body... Cheap parts in there. Install replacement capacitors. I use Nichicon but any brand should work.

Hope this helps.

Oh great this is incredibly useful, thank you so much. Yep, it's the original 1.2amp supply.

I'll order some caps in the next couple of days then start the disassembly!