Magnavox 32" RS3160 31T102 dead/click

[Mike]

I got this magnovox that was completely dead with only a click.
found horiz output transistor shorted, and replaced. noticed the set had the
vertical output IC replaced at one point along with its associated diode and
resistor.

after replacing the horizontal output transistor, the set now powers on
momentarily with a good picture, but goes into shutdown 5 to 10 seconds
later. then the set powers back on automatically, and the cycle keeps
repeating like clock work.

Ruled out the CRT by removing neck board, and ruled out an overload via vert
IC by cutting its supply. same issues, found bad solder around the
horizontal drive transformer and resoldered this and other nearby components
to no avail.

I dont think its the flyback, or i wouldnt have any HV or picture at all.

Only thing left is electrolytics in the power supply and possibly the yoke.

Any ideas? Thanks...

 

[AJ]

Some of the NAP chasis have a horizontal deflection service kit which is
supposed to make the chassis more reliable. Possible that your specific
chassis may need it's application. Check with NAP in Greenville, Tennessee.

 

[Mike]

yea ive tried just about everything on this chassis. there is something that
isnt normal though:

i have 130v going into the flyback, which is normal, but i got 180v sitting
at the collector of the HOT while running. also it causes my meter to start
going random when powered on, so i had to use an analog to take the voltage
reading from the HOT.

 

[James Sweet]

yea ive tried just about everything on this chassis. there is something
that isnt normal though:

i have 130v going into the flyback, which is normal, but i got 180v
sitting at the collector of the HOT while running. also it causes my meter
to start going random when powered on, so i had to use an analog to take
the voltage reading from the HOT.

Is there a damper diode separate from the HOT?

 

[Mike]

no. its built into the transistor.

I believe the micro is bad. or the supply feeding it is bad.

if i turn it off by remote. it will stay off
for 10 seconds and then try to kick back on to channel 3.

Now, if i turn it off, and back on with remote, and if i keep channeling up
and down with the remote, the TV stays on and works fine. as soon as i quit
feeding the micro input with the remote, it powers off again.

so basically if i keep channel up/down on the remote, it will stay on and
work fine. as soon as i let go of the buttons and leave it sit, it goes out
and recycles back to channel 3 with no volume.


some things to make you go hmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm....