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Thanks for your input. I've ordered some new RAM and we'll see what happens. I appreciate the offer, khannonnd, but I'm in Michigan and I doubt you'd like to send it off that far. I've already replaced the one electrolytic capacitor on the RAM board, checked the continuity of all the pins and...

Hi everyone, I'm back for the holidays and am giving another go at this stubborn Apple ///. I'm happy to announce that I think I'm getting somewhere finally! When I recapped my power supply a while ago, I found a suspicious testing transistor in place of where IC1 should go. After researching...

Just to get some context, what OS and machine are you using?

At least in my experience, the flyback transformers in these machines are pretty hardy. I wouldn't worry about it until all other avenues of repair have been explored. For the corrosion on the battery holder, I would take a cotton swab with vinegar and clean off as much as you can. The...

Hi Max, I've experienced the same problem you're describing. I believe it means that your I/O board is not functioning correctly - although the system may recognize it, it's not dealing with the soft switch / interlocks correctly. The next step I'd suggest is making sure that all the gold...

Although filter caps do frequently go bad and should be replaced, I doubt that's the problem here. Does the screen flicker back on if you tap the right side of the case? If so, you might have the typical problem of the flyback solder joints cracking. Reflowing the solder joints around the...

Hi goncalo, I'm not too experienced with the Classic in particular, but I'll try to come up with some more stuff you can check. First of all, it would be useful to know the voltages (if any) being outputted. I don't know offhand the output configuration of the Classic, but I'm sure it exists...

Update: I've retested all the RAM, and it all passes the "SYSTEM OK" test on my //e. 

Desperately, yes...

According to the original Apple /// repair manual, the three voltages are +11.8V, +5V, -5V, and -12V.  Talking to someone who's familiar with older supplies like this, he says that the acceptable range is -4.75V to -5.25V for the -5V supply, and -11.4V to -12.4V for the -12V supply. Can anyone...

Hi everyone, I recently got back into my Apple /// repair, and I've come to a point where I need some help. I have the 5V RAM board, 256k model. Earlier this year, I tested my power supply, and although the +12V line was stable, the +5V line was jumping all over the place. I replaced all the...

I'd start by re-flowing the solder joints on the flyback transformer and see if that does the trick. With such a heavy component hanging on its side in a hot environment for a long time, these joints crack and become unreliable fairly often, resulting in flickering video like you described.

I've always started off by using a Q-tip and rubbing alcohol to remove the old grease. After several passes, the drive moves normally again.

Hi Instow, The Lisa 1 had two notoriously unreliable "Twiggy" disk drives, yes. The upgrade from 1 to 2 involved a replacement front panel, different floppy drive case and drives, and slight modifications made to the I/O board. There wouldn't be any evidence other than the serial number if...

Hi Instow, Here's the serial number info I'm *fairly* sure is correct: Your Lisa's serial number begins with a 'B', meaning it was once a Lisa 1 that was at some point upgraded to a 2. It was manufactured mid-1983 (I can't quite remember what the '125' in the manufactured code means...

What I've done in the past is to take a slider pad for the bottom of chair legs (so the chairs don't scratch the floor), shave it down to about half its thickness and to the size of the old pad, and glue it to the stem. It's probably not the best way to fix it (the cassette pad idea sounds...

Hello, First of all, the Mac 128k is not compatible with the 800k external drive.  The fact that the Mac boots from the disk sporadically is peculiar... a couple of things could be wrong, as I see it. The disks have gone bad/lost some of their data over the years. It's possible, but for it to...

I'd suggest first testing the intermittent keys with a continuity tester to see if they are the problem, or if the problem lies elsewhere. If they don't work reliably with the tester, there's your problem. If they do, then you may have larger problems... Do the traces on the back of the board...

Oops, you're right! Sorry for the confusion.

I've encountered the same issue with some of my 400k drives. I'd recommend not running any more disks through until you have a fix, as the plastic head sometimes can scratch the media surface of the floppies. I've had some luck in the past taking a felt pad (like you'd put on the bottom of chair...