Many people distribute a parts kit for this model of television. It
includes a dual power supply transistor in a single package, fusable power
supply resistor, and new HOT (Q502).

After replacing these parts the tv comes on but soon after it starts heating
up and the right side of the horizontal deflection starts to pull inward.
See this link to an actual picture of it in action
http://www.bass-x.com/sony.jpg (note that the dark area toward the bottom is
actually just a scan line, the camera was quick). If turned on soon after
going into protection, it will blow out all three parts.

Shooting some cold spray in the HOT area straightens the problem up quickly
for a minute. The only part left leading HV to ground in that area are some
high voltage film caps (C509, C527, C511, & C513). C511 is a large red
brick type which is probably the problem. I have also replaced D502, D503,
& D504 (damper diodes). See http://www.bass-x.com/sonyhot.jpg for a peek at
the schematic in this section. I am also putting the enitre schematic out
their if your an ambitious problem solver like me...
http://www.bass-x.com/sonymanual.jpg Lastly... I have resoldered everything
in the entire area after reading about numerous flyback solder flaws.

I guess I am looking for someone who might have run across this before and
remembers the repair. I am expecting it is probably a leaky/heat sesitive
cap, but could use some encouragement from someone who has been here if you
know what I mean.


Thanks!


Jerry

I have had problems with the driver transformer that is driven from a small
power transistor. This transformer drives the HOT.

If the HOT looses its drive, it will pull max current, and thus blow the
main power supply. It is running in a true class "C" type configuration.
Take care for this.

Try sweating very well, the leads of this driver transformer before trying
another one, in case there is a cold solder at the leads. I have had this. I
have also had a defective HV multiplier pull too much current, and reduce
the H scan.

--

Jerry G.
======


wrote in message
...
Many people distribute a parts kit for this model of television. It
includes a dual power supply transistor in a single package, fusable power
supply resistor, and new HOT (Q502).

After replacing these parts the tv comes on but soon after it starts heating
up and the right side of the horizontal deflection starts to pull inward.
See this link to an actual picture of it in action
http://www.bass-x.com/sony.jpg (note that the dark area toward the bottom is
actually just a scan line, the camera was quick). If turned on soon after
going into protection, it will blow out all three parts.

Shooting some cold spray in the HOT area straightens the problem up quickly
for a minute. The only part left leading HV to ground in that area are some
high voltage film caps (C509, C527, C511, & C513). C511 is a large red
brick type which is probably the problem. I have also replaced D502, D503,
& D504 (damper diodes). See http://www.bass-x.com/sonyhot.jpg for a peek at
the schematic in this section. I am also putting the enitre schematic out
their if your an ambitious problem solver like me...
http://www.bass-x.com/sonymanual.jpg Lastly... I have resoldered everything
in the entire area after reading about numerous flyback solder flaws.

I guess I am looking for someone who might have run across this before and
remembers the repair. I am expecting it is probably a leaky/heat sesitive
cap, but could use some encouragement from someone who has been here if you
know what I mean.


Thanks!


Jerry