I've been fighting with a 550 that worked just fine a few years ago and then last year when I went to power it on, it does not boot. I get the power LED, fan, some sounds from the SCSI HD, but no picture or boot chime.
I recapped and cleaned the board, same issue.
I tested a known good Color Classic board in it and the analog board and CRT seem fine.
I put the LC550 logic board in a known good color classic chassis and it has the same problems.
I removed L1, L2, and U1 to clean and inspect underneath and they look good.
The area around the CUDA seems fine.
I tried swapping out the ROMs, same problem.
The board is in really good shape.
I'm at the end of my ability to troubleshoot. Also difficult since I can't check components on the board when it's running for anything overheating.
So, if anyone has a spare 550 board, I might be interested. Have a local kid whose mom is asking for a potential Christmas gift, so wanted to get an idea for cost so I can give her a good price for a working machine. Thanks all!
I recapped and cleaned the board, same issue.
I tested a known good Color Classic board in it and the analog board and CRT seem fine.
I put the LC550 logic board in a known good color classic chassis and it has the same problems.
I removed L1, L2, and U1 to clean and inspect underneath and they look good.
The area around the CUDA seems fine.
I tried swapping out the ROMs, same problem.
The board is in really good shape.
I'm at the end of my ability to troubleshoot. Also difficult since I can't check components on the board when it's running for anything overheating.
So, if anyone has a spare 550 board, I might be interested. Have a local kid whose mom is asking for a potential Christmas gift, so wanted to get an idea for cost so I can give her a good price for a working machine. Thanks all!