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Color Classic: is the PRAM battery required to start up?
Posted by: CVKealey on 2018-01-27 11:14:31
Trying to test my CC's original board, I popped some RAM and VRAM into it and slid it into the chassis. Flipped the power switch, then hit the power button on the keyboard and... nothing. Crickets. Waited a few more minutes and tried the power button again, still nothing. Thing is, I don't have a proper PRAM battery for it, so I'm thinking that may be the issue. Although I know newer Mac's (PowerMacs, anyway) will power on without that battery.
Posted by: just.in.time on 2018-01-27 11:24:16
My Color Classic will boot without a battery in place.  Also, it will maintain time if you only do a soft power-off, but leave the main power switch on at the back of the machine.

That said, the Color Classic has 4mb of RAM soldered onto the board, as well as a bit of VRAM.  I'd try pulling out all the RAM and VRAM SIMMs and giving it a try with just the built in stuff.

Lastly, I think the RAM has to be installed as a pair.  So if you only have one SIMM in place, you will need another identical SIMM.

Best of luck! 🙂

Posted by: CVKealey on 2018-01-27 12:15:25
Actually, on further inspection, there appears to be a cap (C9) missing from the board. That's probably why it won't power on.

IMG_20180127_151333117.jpg
Posted by: just.in.time on 2018-01-27 12:26:47
That could present a problem.  @trag Used to sell kits for many of the logic boards.  If you need help getting a hold of the caps, he is very reliable.
Posted by: techknight on 2018-01-27 13:17:40
umm yep that whole board needs new caps as well as cleaned, especially around the EGRET IC. 
Posted by: Bolle on 2018-01-27 13:35:59
What techknight said.

CC boards are prone to power-on issues due to cap leakage in the EGRET (isn‘t it called CUDA in the CC?) and battery controller area.

The last 3 CC boards I had here did show exactly the same issue as yours. Replacing the caps and removing, cleaning and soldering on the CUDA again fixed it every single time.

The missing cap won‘t prevent it from starting up.
Posted by: techknight on 2018-01-27 13:46:22
Probably CUDA but serves the same purpose. 
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