Sound but no picture (black) on Mitsubishi WS-55805 RPHDTV

[Bill B]

The picture was bright and clear and then all of a sudden went to
black. I powered set down and back up and picture came back, but then
went black again in a minute. Sound works fine, as well as channel
changer, etc. However, it has no picture, no menus, etc. I have
service manuals and schematics, but thought I'd look for some pointers
before I dig into it and see if there are known problems with this set.
Is the FBT the primary suspect? I see the FBT feeds the HV-BLOCK,
which then sends the HV out to the three CRT anodes. Can this go bad
and/or short out FBT, or is the FBT usually to blame? The FBT also
supplies another board with the Focus HV, which then is sent to the
three tubes. Can this be a suspect? Any other things I can look for
and any ways of determining the problem? I see bad caps are a problem
on the VS series, but not sure if they are on the WS models. Thanks!

 

[Motorman]

Here some tips from repair world hope they help: they are kind of crunch up
but I think you can read them.

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TELEVISION MITSUBISHI WS55805 NO CONVERGENCE REPLACED BOTH STK392-040
and 2 120 OHM RESISTORS. ALSO FOUND OPEN 5A PICO FUSE ON -24V LINE - LOCATED
ON SWEEP BOARD!!! -DAVE NAHUM, YORK ELECTRONICS 8/2006
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and if set works with the remote, check S7L22 the enter switch and replace,
also check for loose connections on LF plug.
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(red ok) replace R8C21&R8C22 (3.9 ohm 1 watt) IC8C00 STK393-110 Mits.
part#267P155010 (use original) also check for bad solder conn. on socket VU,
Rays TV
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TELEVISION MITSUBISHI WS-55313 when power up, screen goes bright red with
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#129P070A10 I USED #129P059050 and it worked good. J.D.W.
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TELEVISION MITSUBISHI WS55313 NO COLOR, INTERMITTENT COLOR REPLACE
DOUBLER, OR RESOLDER IC'S ON DOUBLER
TELEVISION Mitsubishi WS55313 No Video Check clock/data line to IC2K01.
clock coming in bad. trace at connector JB showing high resistance. Remove
line and add jumper lead. Also had to replace doubler board. Pix poor and
digitized.
TELEVISION SONY KP57WS550 Green color gets bright with retrace lines, tv
shotts off ***Replaced CRT board p#A1405079A***
TELEVISION Mitshubishi WS55819 Dark Pix - might be intermittant
ReplaceC9A65 (10uF/250V)
TELEVISION Mitsubishi WS-55809 vertical bars replace 2hdw pwb part#
935c966002
TELEVISION mitsubshi WS55809 dead-lighting D9A54 leaky
TELEVISION mitsubshi ws55311 no video has high voltage and audio no
filament found bad solder connections on Q5a26 on power board
TELEVISION Mitsubishi ws-55805 No Pix, No OSD blue tube leaking coolant
on plug RS and IC 703, cleaned plug, and signal board, pulled tube, changed
coolant, sealed tube .


Best regards