Friday, June 4, 2010

JVC TV AV-J21MX: No power problem

This TV that came in for repair was found to have a Horizontal Output Transistor D1878 (on board location Q522) with a short between the collector to emitter. When the defective transistor was pulled out of circuit there was still a short measured from the B+ line to ground. The deflection yoke was unplugged from the TV's main board but still the short was present.


Tracing back towards the power supply it was found out that a shorted RU3A diode on board location D921 is shorting the B+ line to ground.

Replacing the transistor D1878 and diode RU3A restored power and normal operation to the set.

2 comments:

  1. JVC TV AV-J21MX KEEPS ON BLOWING THE LA 7837 VERTICAL I.C., AFTER AN HOUR OF USING, BUT NOT AUTOMATICALLY BLOWS THE VERICAL I.C. WHEN INSTALLED, HELP...

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  2. Please check if the vertical IC you are using is an exact replacement. Also make sure the IC is mounted tightly to the heat sink.

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