Thursday, June 16, 2011

Sony TV KV-21GMR1 power problem:SE115N error amp defect

Sony TV model# KV-21GMR1 is a dead set: no LED standby indicator light, +115V supply to horizontal output transistor measured only 27V and is pulsating.
The SMPS regulator IC STR-S6707 was replaced but still the +115v supply line is dropped.
Even when the horizontal output transistor is disconnected from the circuit the +115V supply will not increase.
An ohmmeter check on the SE115N error amplifier shows that it is internally open circuited.
Power was restored to the set when the SE115N was replaced.

Wednesday, June 15, 2011

Philips CTV 29PT2252/56A (L01.1A chassis)problem:intermittent pincushion distortion

This Philips TV model# 29PT2252/56A exhibited intermittent increase in picture width with pincushion distortion and blanking of picture.
A visual inspection of the printed circuit board reveals solder crack on pin 1 of pincushion transformer on board location 5465/5464/5463.
Resoldering of the cold solder on the pincushion transformer solved the problem of  intermittent picture width and pincushion distortion.