I recently got hold of a Mac IIcx, and have spent a bit of time getting it into a decent condition. The SMD capacitors had leaked, and there are plenty of crusty looking solder joints around the battery, but no battery leak. This all cleaned up reasonably well, and the capacitors were replaced. There was one casualty from the leak, a trace to the realtime clock chip had failed, leading to a slow second advance, but a replacement wire for the broken trace, and all was behaving well.
I also visited the power supply, and replace the dubious RIFAs (one had cracked). I have not recapped the power supply though...
Anyhow, my current problem is that since i'm commissioning some OS builds for the machine, i've been booting it up and down fairly often, and all goes well, then all of a sudden, it fails to boot. I mean by this that the power button brings up the PSU, but there is no start chime. It has never failed whilst running.
I have yet, however, to see any pattern to when it fails, or exactly what to do to get it running again. I invariably leave it for a while with the battery removed, and then it quite often starts up and carries on as if nothing had happened.
My next step will be to check the voltage rails, is it possible that the PSU isn't quite strong enough, or has noise on it's outputs and is marginally working? I didn't replace the larger electrolytics on the main board, are they out of spec?
Any advice as to what to try to convert an intermittently awesome Mac into a fully working one would be appreciated
!One other point, the PSU seems to get warm when plugged in without the machine running. I know there is a low power 5v supply running when connected - does this generate any obvious heat, or is this telling me that the power supply should really be properly recapped?
I also visited the power supply, and replace the dubious RIFAs (one had cracked). I have not recapped the power supply though...
Anyhow, my current problem is that since i'm commissioning some OS builds for the machine, i've been booting it up and down fairly often, and all goes well, then all of a sudden, it fails to boot. I mean by this that the power button brings up the PSU, but there is no start chime. It has never failed whilst running.
I have yet, however, to see any pattern to when it fails, or exactly what to do to get it running again. I invariably leave it for a while with the battery removed, and then it quite often starts up and carries on as if nothing had happened.
My next step will be to check the voltage rails, is it possible that the PSU isn't quite strong enough, or has noise on it's outputs and is marginally working? I didn't replace the larger electrolytics on the main board, are they out of spec?
Any advice as to what to try to convert an intermittently awesome Mac into a fully working one would be appreciated
!One other point, the PSU seems to get warm when plugged in without the machine running. I know there is a low power 5v supply running when connected - does this generate any obvious heat, or is this telling me that the power supply should really be properly recapped?