Perhaps you can help me. I'm working on a Model 1 (VA6), having the same issue--black screen, no audio (but there is the muted white noise when you connect headphones). I'm reading 2.5v from the oscillator and each IC is getting a clock. On the RGB encoder, pins 2, 3, & 4 are getting input signals. The C VIDEO OUT pin is outputting 0.7V. I've tried three different AV outputs--RF, composite and component. I want to blame the cartridge connector, but I tested each individual pin (connector side to underside of motherboard), and got continuity in each and every one. Pin tension also looks good. Even cleaned out any debris from inside. Also should note that this happened after recapping, and all new caps were installed with the correct polarity. So where should I test next?
if it all happened after recapping that's where you should look first. May want to reflow all the joints, its possible that when you pulled one of the old caps out, it took out the pad on top of the board. That's where I would start. On the top of the board follow any traces that go to the capacitors. Check for continuity by placing one probe on the solder joint on the bottom of the board and then check the trace on top. If that makes sense. The traces have a thin coating so you can scrape a little of the coating away so the probe can hit metal.....or just follow it until it connects to another component and measure from there. Hope that makes sense. Best of luck! Let me know how it turns out.
If you know the chips are at least outputting signal. Consider just doing a triple bypass mod. It will by pass the issue in the audio chip. You’ll also get far superior audio and rgb video(no jail bars)
And the awesomeness continues.
Perhaps you can help me. I'm working on a Model 1 (VA6), having the same issue--black screen, no audio (but there is the muted white noise when you connect headphones). I'm reading 2.5v from the oscillator and each IC is getting a clock. On the RGB encoder, pins 2, 3, & 4 are getting input signals. The C VIDEO OUT pin is outputting 0.7V. I've tried three different AV outputs--RF, composite and component. I want to blame the cartridge connector, but I tested each individual pin (connector side to underside of motherboard), and got continuity in each and every one. Pin tension also looks good. Even cleaned out any debris from inside. Also should note that this happened after recapping, and all new caps were installed with the correct polarity. So where should I test next?
if it all happened after recapping that's where you should look first. May want to reflow all the joints, its possible that when you pulled one of the old caps out, it took out the pad on top of the board. That's where I would start. On the top of the board follow any traces that go to the capacitors. Check for continuity by placing one probe on the solder joint on the bottom of the board and then check the trace on top. If that makes sense. The traces have a thin coating so you can scrape a little of the coating away so the probe can hit metal.....or just follow it until it connects to another component and measure from there. Hope that makes sense. Best of luck! Let me know how it turns out.
cool!
Do you by any chance know about an issue with audio? I can only listen to the fx sounds And the other channel is extremely low.
If you know the chips are at least outputting signal. Consider just doing a triple bypass mod. It will by pass the issue in the audio chip. You’ll also get far superior audio and rgb video(no jail bars)