Recent content by MacintoshProblems:P

Update: Good news, it's Fixed! So let's see what happened: while waiting for the small 100 nf capacitors, however indispensable because I found others with rusty legs, it occurred to me that I had seen some small black spots on the Rom's feet, I decided to clean them with a sheet of 800-grit...

Good morning/good evening. Here I am for the news: I took apart the Sony power supply and double checked the voltages and electrolytics, used a couple of voltmeters to verify that the voltages were present at the same time as the power up and everything was running consistently. I also checked...

Unfortunatley I don't have an ESR, that would be the next thing to buy. At the moment I'm trying to find either nippon Chemi-con or Rubycon if I'm lucky. Every now and then I happen to find caps with dubious origins such as Jamicon, Daewoo and other chineese crap (I say chineese because I think...

I have to try with the reset switch, with a restart it always gives the same lines. In photo that I attached to this post, there are the Rom that I used for resolving the issue, but it didn't work. I won't hide that I tried to interchange only the Woz chip but I had a sad mac. I already thought...

Exactly! This is the weird problem that I'm facing! The macintosh after the boot works perfectly but before the boot sequence there's this weird error. Yes, the pattern is the same every time even after some time and at different temperatures. I immagined that it could be a problem related to...

Update 2: First, I changed all 3 ROM: High, low and the Woz one (swim). Nothing changed. Second, I changed 2 simms doing an upgrade to 2.5Mb cutting one leg of the resistor r35, Nothing has changed once again. Third I found a corroded capacitor (this SE went to hell and back), the name's c20...

Have you tried opening it up and adjusting the potentiometers on the side? They might've corroded and that would be my guess for this issue. I'll attach a picture of what it should look like. idk if you already fixed it or the potentiometer is broken

Update: the psu is fine after re-capping and... nothing changed. The good news is that it has better reading now: 12.11v instead of 12.54v and 5v instead of 5.18. The bad news is that nothing changed: the screen is still the same.

even though after that it boots and works fine? I already checked the power supply and it all seemed fine Edit. My fluke multimeter reads 12.54v and 5.18v so idk it seems fine I guess

Yes I did, I also re-capped any that had the same voltage just to be sure. It had an error before re-capping. I re-capped all the 33uF 16v on the logic and all of the electrolytics on the analog board. I didn't touch any of the power supply ones because it gives the correct voltage and it works...

here are some more images of what happens next

Hello, so I recently found some old macintosh computers lying around so I wanted to see if I could make any of them boot and work. After a lot of tinkering (and re-capping it twice), I decided that I really don't know what's causing the issue and I can't find anyone that has/had the same issue...