Hi everyone. I know lots of threads on this and Deb64 has helped with diagnosis and solutions. I have a clarification question on a no sound issue. History of unit is I purchased it from someone that had it in working condition until it started to make the humming even when off effect that is a known problem. He opened up the unit but I don’t think did anything electrically except try to get a failing DC in jack working. I know for a fact the aftermarket power supply he was trying to use puts out 7.2V on my fluke meter. He was trying to power with battery pack and was getting no power at all to the unit and gave up. When I got it home and inspected the battery carrier found corrosion in the terminals. Cleaned up and battery power working fine. Unit was slipping in the idler area but I disassembled and cleaned up and speed seems to be consistent even without replacing any tires. Not running fast from my estimate so I think speed control is working. Can’t be sure though with no sound. I removed CP301 hoping sound would magically come back but unfortunately didn’t help. My clarification question is when I play a tape I get no audio out of the headphones but I do get progressively louder hiss as I turn the volumes slider up. From other troubleshooting threads I assume that is helpful in understanding what my issue is. Any advice on next steps would be great. Thanks!
Other note. I have 11.06V on the orange wire from the DC-DC transformer. I did NOT solder the green wire back onto the pad where it connected to the CP301. Do I need to solder that back on? thanks!
Ok sorry everyone but I figured it out. It was the playback record internal switch. No matter where I had it I was getting nothing. I doused it with deoxit and switched back and forth 20 times and it now works. so follow up question then. Can I diagnose whether my CP301 is good before soldering it back in? Thx
