Mac Classic not starting

[BadGoldEagle]

Hi

I'm trying to help out someone who posted an ad saying that his classic wouldn't start anymore.

He is 78 and French, so he doesn't speak English at all. 

He uses his Classic on a daily basis (I think he didn't even think about replacing it since 1990) and this year it started acting weirdly: he had to pop on and off the power switch several times until the damn thing eventually started. Now it does not start at all. No HD, no image, no everything, same as if it was unplugged.

I'm not a Classic wizard but I think it is psu-related. I saw this on the Apple Community website suggesting just that: https://discussions.apple.com/thread/1813216?tstart=0

I don't think the fuses are the problem, because if they go wrong, they burn immediately. 

But since he needs his computer to do the accounting for his business (lol) I told him the best would be to swap that analog board. But now I've had a rethink: if you swap the two boards, there will be two problems: 

1/ Different types of CRT connectors (Rev A until '90 and Rev B from '91) so we would need the right board.

2/ Then CRT adjustments have to be made and I'm not sure he can handle that himself. I can not do that.

The Apple repair guide says you need a special CD with some pics to adjust brightness and stuff... Does he really need that??

Now if some of you have a better idea, I'm sure he would be thrilled to hear it.

I'm going to ask him to send me a pic of the CRT connector, so we'll know which type of board he has.

 

[MJ313]

Are the capacitors all original? If they haven't been replaced, that's going to have to happen.

 

[BadGoldEagle]

The caps haven't been changed but I didn't think they could cause that.

I thought the caps caused sound issues and the Simasi mac thing.

And on the Apple Communities page, the guy installed his mobo into a working Classic, and the Classic started. So I don't think the caps on the mobo at least are defective (for now). But what about those on the analog board tho?

 

[BadGoldEagle]

I haven't done it before but is it really that hard to adjust the brightness and contrast once you swapped two boards?

 

[Macdrone]

YAH!!!! another one for the day.

CAPITY CAAAAPPPPSSS!!!  replace them.

 

[Tiptoeturtle]

You might consider finding a second Classic-or-later compact model of Macintosh that is working and for sale, buying it secondhand, and swapping the hard disk from the inoperative computer into the operative one, then backing up all the data into a third (more contemporary model of) computer with a more contemporary release of the accounting software (if any, uh oh). If the sick Classic still has a working hard disk it has been working on borrowed time for a decade or more.

 

[bibilit]

I can recap the Analog Board for him if required, even the LB.

Also have a couple of Complete Units for a test if required (those are keepers anyway) to locate the problem.

 

[Tiptoeturtle]

It could also be that the power switch itself mechanically broke.

 

[eR1c]

The caps haven't been changed but I didn't think they could cause that.

I am not an expert, but having brought my Classic II back from the dead (and having re-capped the AB and motherboards) I know first hand that at least the Classic II will have no display if a cap' associated w/ the display is bad.

Personally i'd start w/ a re-cap ...even if that doesn't solve the issue it will be necessary.  Its easy to do and shouldn't cost a fortune.  

 

[eR1c]

I love that someone has not stopped using their classic Mac on a regular basis from back when it was manufactured.  Awesome! 

 

[Dav]

First I would suggest to simply wash the logic board (remove battery first !) with water and a little dishwashing liquid. Use a very smooth toothbrush (like the ones made for kids) and insist gently around the capacitors. Rince carrefully and rince a second time the board with demineralised water. Let the logic board dry at least a full day and put it back in the Classic. If it brings your Classic back to life, you know it's a capacitor leaking problem. The trick worked for me with a Classic II that didn't power on.

 

[Paralel]

Forget about dishwashing liquid, go right to high % (90%+) IPA or acetone.

 

[Elfen]

It depends on that symptoms the Classic II is showing.

If you got a checker board or large horzitonal bars, then the logic board needs recapping. I say recap the logic board anyways as recapping the board brings back 90% of all Classic II problems. And any Mac this old will need the caps to be replaced anyways.

If there is no video, it's the harness jack on the analog board being broken at the solder joint and other analog board problems- recap the analog board and replace the usual suspects (T1, CR1, so on...).

It would be best to do both. But for him is the expense worth it? One has to act fast before some relative forces him onto a PC.

 

[eR1c]

..curious if you've made progress on this? update please!