Color Classic - Problem with analog board

[macintosh2002]

Hello,
my name is Patrick, I have two Color Classic Macs in decent cosmetic condition and some problems with both (one smaller, one bigger) and I hope someone could help me with an idea to fix both.
The first one was working when I got it, I recapped the logic board and after a few hours of using, the SCSI HD is dead and it won't boot, but ok. I noticed that the image on the screen is a bit brown, and not that shining white as usually. Is there a way to adjust the color representation?

The second CC I got was sold as defective, the seller told me that nothing happens when he tried to start it. When I was at home and try to start it, it chimed and boot, nice I thought! But then it happened that this CC could no longer be switched on. However, with power cord plugged in, after 1-2 days it worked again and it worked twice more, but then not anymore. I noticed, that the case on the outside was very warm (close to the handle). I started to recap this logic board too, and almost all faulty caps of the analog board.
Now it starts immediately after the switch on the back is switched on(!) Happy clear and loud chime, green light is also shining (second SCSI HD also died...) but the screen won't turn on, it stays black. Is there a circuit diagram of the analog board available?
BR, Patrick

 

[8tto]

Hi! Congratulations on new Macs!
I`ve recapped two Color Classics (motherboard and analog-board), but never had to, or had the ability to, fix anything more electronically complex.

The Service manual (https://tim.id.au/laptops/apple/legacy/color_classic.pdf) is great is a grate guide for fixing color- or geometry problems with the CC. You should find, download and use an utility called "Display Service Utility" for best results. I`ve found the Powerbook version best , as it can display solid colors. Be careful, as you have to work near high voltage! I also ended up replacing the adjustmentpots for the display on the analog-board

For the one CC that wont turn on I`m not sure:
- Did you reconnect all the cables?
- Double and triple check the new capacitors?
- Check all the solders on the analog-board?
- Clean the edge- connector on both boards?

I`m not aware of schematics for the analog-board, I`m afraid, and haven't got any tips regarding the powersupply. As the Mac turns on as soon as you flip the switch, it might be something with the softpowercircuit on the motherboard?

Good luck!