Any idea what causes fm to suddenly go out to static and never come bk on after cool dn and restart. It started making funny noise for 20 seconds and then just quit?
@@richardadelberg8961 Check for 12 volts on pin 5 of the FM front end. If that’s missing check D3 for short and the power supply 12V rail. If the 12 volt is good going into the front end then I would look at the multiplex. Any of the multiplex amplifiers could cause no FM so you will need to start with IC1001 pin 7 and work your way through the filters and IC1002, 1003, etc. If that is good then look at IC1006. You should have 10.5 volts on pin 16, 19KHz on pin 11 and the stereo output is pins 4 (Left) and pin 5 (right).
@@tipsfromthetechbench4589 thank you sir!!! Was playing and just started a sizzling sound for like 20 seconds and freq tone just sliding up the freq scale then hiss. Something cooked.
Thanks! Just got one a few days ago and boom!..your video is a god send
Thanks 🙏😊
Any idea what causes fm to suddenly go out to static and never come bk on after cool dn and restart. It started making funny noise for 20 seconds and then just quit?
Usually power supply. If AM works and FM doesn't check the 12V rail. If AM and FM are bad it could be the +/- 18V.
All other inputs wk fine. Am is fine. I guess I’ll start checking diodes
@@richardadelberg8961 Check for 12 volts on pin 5 of the FM front end. If that’s missing check D3 for short and the power supply 12V rail. If the 12 volt is good going into the front end then I would look at the multiplex. Any of the multiplex amplifiers could cause no FM so you will need to start with IC1001 pin 7 and work your way through the filters and IC1002, 1003, etc. If that is good then look at IC1006. You should have 10.5 volts on pin 16, 19KHz on pin 11 and the stereo output is pins 4 (Left) and pin 5 (right).
@@tipsfromthetechbench4589 thank you sir!!! Was playing and just started a sizzling sound for like 20 seconds and freq tone just sliding up the freq scale then hiss. Something cooked.