Riddled TV Repair Forum

MikeB · Guest

exactly 1 year ago i fixed it, it had bad fluid, and a bad cold side controller IC. then it ran fine. although it had a bad cap in the vertical i never got around to fixing. it would start off in bad linerity, cold, and then work its way back to normal.

a couple days ago it would play fine, and then the picture woudl shut down, but the sound would stay playing. you could power off for an hour or so, and power on, it would work again. now it wont come back on at all, just sound only.

im assuming either the capacitor i never got to has caused the vertical IC to go into scan shutdown, or somethign else is up. bad solder maybe. odnt know, have to go over there in a couple of hours to check it out.

any ideas?

Google

MikeB · Guest

well took a look at it. there is a bad trace somewhere in the board. dont
know where exactly.

i resoldered everything in the vertical and horiz section. it powers up, HV
kicks on, and then it shuts down. power LED stays on, audio comes on.

but if i push the heatsink where the horiz out is. (not HV out.) youll hear
a pop and then you can hear the horiz whine in the yokes. but no HV until
you reset (latched into shutdown). i let go of the heatsink, it cuts out.

if i push on the heatsink, and re-power the TV, she powers up and comes on.
let go of the heatsink, it cuts out, shuts down.

so i tried everything to find it. resoldered leads of the hot, and others.
so i wedged a rivet between the vert and hot heatsinks to get it to stay on
and work until i figure out why.

any ideas??

DavidL · Guest

Eek...intermittents...you could use an oscilloscope to trace whatever
missing signal is causing the shut down or you could use the old plastic
sewing needle trick. Sometimes the poke method reveals an intermittent
sometimes it doesn't. I have used this method in the past, it does narrow
the intermittent to an area and then you could start troubleshooting from
there. Not sure about this model but some model TV's will shutdown if
vertical or horizontal signals do not get back to the micro. Good luck.

John · Guest

Mike, On the 700 series. seem I recall somthing about a leaky diode D902, On
the large signal board. If its there might want to check it. D902 P.n
4835-130-37115.

John