CTC 203

[Michele Smith]

I've discovered the horizontal driver Transistor is shorted Emitter to Base,
and have been endeavoring to find the cause of this short. Any help would be
appreciated. Thanks. Mark.

 

[[email protected]]

Is it shorted Collector to Emitter? Then it is bad.
If you read around 40 ohms base to emitter, it is good. Look up the
datasheet for any horizontal output transistor and look at the internal
B-E resistor.

Might want to brush up on electronics and consumer electronics repair,
i.e. TV sets.

 

[sofie]

Michele Smith:
Make certain that you test the transistor "out of circuit" to obtain
conclusive results.
The HDrive transistor is usually a "standard" NPN TO-92 silicon so the
testing is usually straight forward, whereas the HOT usually has an internal
resistor and damper diode which will complicate the test results and cause
confusion unless you know what to look for in your meter readings.
Shorted transistors can be the result of faults in the surrounding
circuitry.... or.... it could have just been the time for the transistor to
fail without any other related circuitry failures. Old fashioned
troubleshooting, testing and experience will speed the diagnostic process.
You might want to go to the website for this newsgroup at
http://www.repairfaq.org/
There you will find a wealth of technical helps.