CD32 – No composite and glitchy afterwards

CD32 came in for repair, has been recapped for 4-5 years ago. No composite signal and S-Video totally distorted.


Checked the signal on the CXA1145, they looked good, also check signals from CXA to connectors, everything looks good. But still no composite and distorted s-video. I decided to replace the CXA1145, delayline, band filter. the delayline and band filter came from scrapboard. But still same problem.

Sometimes the s-video output looks good, but after several minutes the display starts to distort. So is it a capacitor or something else. Checked everything again, but same conclusion.

Replaced the DAC and a 4066, same problem. I took my scope to see if I missed something:

As you can see I detected some corrosion, hmm could a be the problem? I there is electrolyte inside the via it can behave as it did. cleaned everyhting and added new wires.

The signal is going to R265 (_BLANK Signal) .

Signal before clean/fix:


That looks good.. let see if screen output is working on composite:


Yes! That was the problem.

Problem was _blank signal from LISA to video DAC was partially interrupted