How do I stop H.O.T. blowing up?

[Peter Lowrie]

I'm a bit stuck with a Mitzi 29" telly. I've checked every electrolytic, IC
and semi on the board(s), still everytime I stick a new
horiz-out-transistor in it, it dies. Someone said something about loading
part of the circuit with a lightbulb but i don't know where.

B+ is 105V, it has a new LOPT and a new video amp chip (LA3838).

It's a bit of a probelem in that I have no more hair to pull out. Any
suggestions would be appreciated.

Peter

 

[Rudolf Ladyzhenskii]

What does drive pulse like?
What about FBT -- it can be faulty. Also, shorted yoke can give you teh
problem. Dry joints on drive transformer and/or FBT.
Did you measure B+? Unregulated B+ can blow HOTs.

Rudolf

"Peter Lowrie" <peterlowrie@consultant.com> wrote in message
news:cU3gb.6394$tv1.715738@news02.tsnz.net...

I'm a bit stuck with a Mitzi 29" telly. I've checked every electrolytic,
IC
and semi on the board(s), still everytime I stick a new
horiz-out-transistor in it, it dies. Someone said something about loading
part of the circuit with a lightbulb but i don't know where.

B+ is 105V, it has a new LOPT and a new video amp chip (LA3838).

It's a bit of a probelem in that I have no more hair to pull out. Any
suggestions would be appreciated.

Peter

 

[Phil Allison]

"Peter Lowrie" <peterlowrie@consultant.com>

I'm a bit stuck with a Mitzi 29" telly. I've checked every electrolytic,
IC
and semi on the board(s), still everytime I stick a new
horiz-out-transistor in it, it dies.

** How do you know your supply of HOTs is genuine ??

Lots of duds are being sold into the spare parts market.




.......... Phil