RCA

This unit came in as dead. A little detective work found R409 open ( 1 ohm @ 1W fusible ) due to a shorted vertical IC ( STV9302A ). After repairing this the unit was still dead. BEWARE that this set has a front panel lock! Use a remote when troubleshooting this chassis for dead set symptom! I will share a few things that may be helpful.
In STANDBY mode expect the following voltages- - D830 = 3V, D833 = 1.9V, D831 = 16V.
The source of the 5V line to the keys are Q830 B=8.1V, C=15.9V, E=7.4V which feeds Q002
- B= 5.7V, C= 7.2V and E= 5.0V to the keys and IR sensor. Any DC load on the flyback will keep D831 from reaching it's potential of 109V and keep the unit dead.