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Jamie wrote:
wrote:

Jamie wrote:

wrote:

Having big issues in solving this problem.
Power switch on this model is mechanical.
Here is the Problem.........
Push the power switch on and the red light lights up.
That's all.....
No High voltage, no audio, absolutely dead.
I checked the voltage reg....OK
I checked the HOT....OK
Checked ossilator HOT coil.....OK
Checked flyback......OK
Looked for cold solder joint....seems ok
Checked all power resistors...OK
Can't seem to find a schematic for this model either.
This TV is fairly new with hardly any use on it at all..
I checked with other techies in my area and they have a couple of these
TV's on their bench as well with the same problem...

I am stumped on this one.... :-(

I need some help on this one...
Any suggestions?
Thanks in advance
Michael Bearns

Look for an onboard POWER RELAY, most likely in a black rectangular
case.
There was one very cheap TV, I once had my hands into that used the
heater of the CRT as part of the power supply. if that opened, it would
also not allow the power supply to start up. It was a good idea how
ever, bad CRT's many times would cause major problems else where when
things like ARC's took place.

Also, look for the degaussing circuit which is suppose to time out
and then switch on TV. It's been a while since I've really have had my
head into TV's. I've found not much profit in them. Just more of a side
line to help people out around me.

Thanks for the information jamie......
This TV does not have a relay.....
CRT heater is working......
degaussing circuit does time out......
--------------------------------------------
:-(

Well, Have you check to see if there is any HV B+ at the collector of
the HOT ?
Open yoke and flybacks can also cause issues.
A lot of times, You need a feed back voltage from the flyback which
is normally a low voltage supply for the rest of the unit.
it's also used to insure power is good and keep the main supply on.
normally, a momentary flicker of this voltage will cause main supply
shut down.. Some times its simply bad caps at this section of the
unit and thus will produce a line pulse effectively the same as a transient
pulse that disables the main supply..

What you need to do is connect a scope to this and see if
you're getting a brief signal to the HOT Base and collector and
also look at any low voltage secondary taps for badly filtered
supply outputs that will show as a pulse on start attempt.

Happy hunting.

I have checked the yoke for opens.....OK
Flyback has been replaced.... No Change
All Caps are within their specs.... high voltage section.
B+ voltage is their as well.....
scope is being serviced and calibrated at this time, so this is not an
option.....
I am going to check the other things you mentioned tommorrow as I'm
getting eye strain. lol
thanks for the info.......