View Single Post
  #1   Report Post  
Posted to sci.electronics.repair
sofie
 
Posts: n/a
Default ctc203 B+ too high

CTC203J2 RCA Hospital Model #J20541

Intermittent 3 strikes symptom but "sometimes" starts up, turns on and
displays great pic and good sound but B+ seems to regulate about 10 - 15
volts too high.... about 154 vdc.
I found that if I reduce the B+ going to pin #2 of flyback by about 10 volts
with a 27 ohm resistor that it powers on just fine, every time, so I am
hoping that if I can reduce the regulated B+ to a lower correct voltage that
all will be OK and will work fine as it should without the voltage dropping
resistor.
I checked values of resistors and electrolytics ESR all around SMPS primary
(changed R14108, 0.1 ohm, 3W) and secondary without finding any significant
deviations from the norm. Resoldering around Flyback, HOT, L4401, HDr
xfmr, etc had been done and has been redone.

How do I reduce the B+ ..... adjust? component change?

TIA
--
Best Regards,
Daniel Sofie
Electronics Supply & Repair
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -