PhillipsMagnavox PR1902 19" TV dead Chassis 19Y600-7560 Help

R

RobC

Guest
Hi,

Need help from anyone familiar with this chassis. Symptoms..Press power
button, starts up for about 1 second and shuts down. Hold power button
down, continues to run but picture is shrinked in from the bottom and right
by about 1". Took a look inside. Diode 6440,6441 and 5445 look like they
have been running hot, but test good. Unplugging the horizontal yolk allows
the set to power on and come up with full vertical deflection, audio, hv,
working tuner and no shutdown. What could cause this other than a shorted
yolk? Anyone with any knowledge of this problem? There must be a short
somewhere, but I really don't think it's the yolk.

Replies greatly appreciated as this set is for my father who is in a nursing
home and now has no TV.

Thanks,
Rob
 
components in the horiz yoke return, pincushion, etc. probably not a shorted
yoke but failed components on themain pc.
"RobC" <rob-jenny@worldnet.att.net> wrote in message
news:IbBYb.13664$aH3.449255@bgtnsc04-news.ops.worldnet.att.net...
Hi,

Need help from anyone familiar with this chassis. Symptoms..Press power
button, starts up for about 1 second and shuts down. Hold power button
down, continues to run but picture is shrinked in from the bottom and
right
by about 1". Took a look inside. Diode 6440,6441 and 5445 look like they
have been running hot, but test good. Unplugging the horizontal yolk
allows
the set to power on and come up with full vertical deflection, audio, hv,
working tuner and no shutdown. What could cause this other than a shorted
yolk? Anyone with any knowledge of this problem? There must be a short
somewhere, but I really don't think it's the yolk.

Replies greatly appreciated as this set is for my father who is in a
nursing
home and now has no TV.

Thanks,
Rob
Click to expand...
 
I poked around a bit more with my scope, but don't have any schematics. B+
is at 95V and looks good and clean DC. Input to the horizontal pre-driver
is a nice clean square wave. The input to the base of the HOT is very messy
looking amplified version of the pre-drive making me think that the
pre-driver transistor may be having some issues. The diodes that appear to
be running hot are in the pre-drive circuit. I am still a bit concerned
about the SMPS because some of the signals coming out of it are very strange
with alot of ringing. I'll keep digging in further.
-Rob


"Art" <stubby@comcast.net> wrote in message
news:Z-ydnanKfKX996jdRVn-uA@comcast.com...
components in the horiz yoke return, pincushion, etc. probably not a
shorted
yoke but failed components on themain pc.
"RobC" <rob-jenny@worldnet.att.net> wrote in message
news:IbBYb.13664$aH3.449255@bgtnsc04-news.ops.worldnet.att.net...
Hi,

Need help from anyone familiar with this chassis. Symptoms..Press power
button, starts up for about 1 second and shuts down. Hold power button
down, continues to run but picture is shrinked in from the bottom and
right
by about 1". Took a look inside. Diode 6440,6441 and 5445 look like
they
have been running hot, but test good. Unplugging the horizontal yolk
allows
the set to power on and come up with full vertical deflection, audio,
hv,
working tuner and no shutdown. What could cause this other than a
shorted
yolk? Anyone with any knowledge of this problem? There must be a short
somewhere, but I really don't think it's the yolk.

Replies greatly appreciated as this set is for my father who is in a
nursing
home and now has no TV.

Thanks,
Rob
Click to expand...
 
You must log in or register to reply here.

Welcome to EDABoard.com

Sponsor

Back
Top