Quadra 840AV - no chime

[kupouzar]

Hey all, I've managed to get a nice Quadra 840AV. I've cleaned the board with alcohol and recapped it using tantalum caps. It hadn't worked before and has remained the same afterwards. I've found and bodge wired some broken traces between the AMD SCSI/Ethernet controller and the VLSI nearby. There were two more between another VLSI and the AT&T DSP. But nothing helped and now I don't know what to do anymore. The PSU is a known working ATX rebuilt to work with the 840AV. The CPU and SIMMs are okay as I tested them in another machine. Any tips?

 

[kupouzar]

I also noticed that the CPU and several other chips (DSP and VSLIs) get warm. The clock sources also work fine, I checked them with a scope. The voltage of the reset line seems to be around 4.5V at all times.

 

[Byrd]

Keep checking and cleaning around those large custom ICs, often taken out by cap goo. A magnifier would come in handy

 

[croissantking]

Having now revived two boards, I can pretty much guarantee you’ve got one or more broken traces. They’re likely to be in the vicinity of the old leaky caps.