Golf wrote:
I have a general question regarding horizontal frequency in a TV. I
have this set that tries to power up but shuts back down. Anyhow, I am
going to scope the H drive pulse and such, but if the frequency isn't
what it should be (suppose to be around 15.7Khz?), would this likely
be part of a protection circuit shut down in some models? Would the
same be true for Vertical as well? The screen and heater voltage is
swinging also. I am trying to repair this with as little help as
possible. This is why I'm not going into details on model #, make, and
such. Thankyou group.


As others have said, information is key. However there are a couple of
things you might try to zero in on the problem:

From your comments, I assume that the HOT is not shorted. Jumper the
base to the emitter of it to force it to stay turned off and see if the
power will stay up. Of course you will not see a raster due to the HOT
being shorted out, but if the power stays on your problem is located on
one of the output terminals of the flyback transformer. If this is the
case look for a shorted diode off of one of those secondary windings.

It could be other things, but that is often the reason based upon the
symptoms you described.