Sony Projection TV intermittent image problem -- KP46WT510

B

Brian

Guest
All:

I've been impressed in the past with the accurate answers provided here
in this newsgroup (e.g., APC UPS fix), so I hope there's help again! :)

My 5 year old Sony projection TV (KP46WT510) has developed an image
problem. Here's some pictures:

Bad: http://www.networksplus.net/standingwater/tv1.jpg

Also bad: http://www.networksplus.net/standingwater/tv2.jpg

Just starting: http://www.networksplus.net/standingwater/tv3.jpg

Sound is OK, and I've isolated the problem to the TV (not the cable box,
etc.).

The "whack" and overnight unplug "reset" tests didn't fix the problem.

There's no new EM sources nearby, other than an occasional black
helicopter at night (green in the day). :)

The signal is being delivered via standard CATV coax. The image
intermittently switches between OK and the thin horizontal color bars
(R+G+B) in varying proportions (never to 100% of the time). The bars
vary with the input-signal.

Oddly, DVDs play fine (also through the CATV coax connection). Must be
the higher resolution scan than for CATV.

So my _guess_ is the low-res circuiting that creates the CATV pictures.

I've read on-line about typical convergence problems (and replacing the
two STK392-560 ICs), but my TV's image problem does not seem to be one
of the common convergence image problems.

Anyone seen/fixed this specific problem? If so, how? (A service call
is not likely since I'm a unrepentant diehard DIY'er)

Thanks!

Brian

(If e-mailing please be sure to edit my address)
 
"Brian" <standingwater@EditThisOut.networksplus.net> wrote in message
news:EfadnYtqJ9qj6N7XnZ2dnUVZ_hKdnZ2d@kans.com...
All:

I've been impressed in the past with the accurate answers provided here in
this newsgroup (e.g., APC UPS fix), so I hope there's help again! :)

My 5 year old Sony projection TV (KP46WT510) has developed an image
problem. Here's some pictures:

Bad: http://www.networksplus.net/standingwater/tv1.jpg

Also bad: http://www.networksplus.net/standingwater/tv2.jpg

Just starting: http://www.networksplus.net/standingwater/tv3.jpg

Sound is OK, and I've isolated the problem to the TV (not the cable box,
etc.).

The "whack" and overnight unplug "reset" tests didn't fix the problem.

There's no new EM sources nearby, other than an occasional black
helicopter at night (green in the day). :)

The signal is being delivered via standard CATV coax. The image
intermittently switches between OK and the thin horizontal color bars
(R+G+B) in varying proportions (never to 100% of the time). The bars vary
with the input-signal.

Oddly, DVDs play fine (also through the CATV coax connection). Must be
the higher resolution scan than for CATV.

So my _guess_ is the low-res circuiting that creates the CATV pictures.

I've read on-line about typical convergence problems (and replacing the
two STK392-560 ICs), but my TV's image problem does not seem to be one of
the common convergence image problems.

Anyone seen/fixed this specific problem? If so, how? (A service call is
not likely since I'm a unrepentant diehard DIY'er)

Thanks!

Brian

(If e-mailing please be sure to edit my address)
Click to expand...

No, but it is definitely not a convergence problem.

Leonard
 
Leonard Caillouet wrote:
"Brian" <standingwater@EditThisOut.networksplus.net> wrote in message
news:EfadnYtqJ9qj6N7XnZ2dnUVZ_hKdnZ2d@kans.com...
All:

I've been impressed in the past with the accurate answers provided
here in this newsgroup (e.g., APC UPS fix), so I hope there's help
again! :)

My 5 year old Sony projection TV (KP46WT510) has developed an image
problem. Here's some pictures:

Bad: http://www.networksplus.net/standingwater/tv1.jpg

Also bad: http://www.networksplus.net/standingwater/tv2.jpg

Just starting: http://www.networksplus.net/standingwater/tv3.jpg

Sound is OK, and I've isolated the problem to the TV (not the cable
box, etc.).

The "whack" and overnight unplug "reset" tests didn't fix the problem.

There's no new EM sources nearby, other than an occasional black
helicopter at night (green in the day). :)

The signal is being delivered via standard CATV coax. The image
intermittently switches between OK and the thin horizontal color bars
(R+G+B) in varying proportions (never to 100% of the time). The bars
vary with the input-signal.

Oddly, DVDs play fine (also through the CATV coax connection). Must
be the higher resolution scan than for CATV.

So my _guess_ is the low-res circuiting that creates the CATV pictures.

I've read on-line about typical convergence problems (and replacing
the two STK392-560 ICs), but my TV's image problem does not seem to be
one of the common convergence image problems.

Anyone seen/fixed this specific problem? If so, how? (A service call
is not likely since I'm a unrepentant diehard DIY'er)

Thanks!

Brian

(If e-mailing please be sure to edit my address)


No, but it is definitely not a convergence problem.

Leonard
Click to expand...
Thanks, that's a start!

Others seen or solved this problem?

-Brian
 
What about checking for a glycol coolant leak from one of the CRT's onto one
of the boards? If your pictures were more blotchier, Id say its time for a
coolant change.
 
Circuit wrote:
What about checking for a glycol coolant leak from one of the CRT's onto
one of the boards? If your pictures were more blotchier, Id say its time
for a coolant change.
Click to expand...
Glycol coolant? I though you were kidding at first. But it is there,
apparently.

I pull the back cover off (after unplugging and letting it cool off for
a couple of hours).

No signs of leakage, and the little rubber coolant expansion bulbs on
each lamp are full.

Wiggled all the electrical connectors I could find, but no change.

"Id say its time for a coolant change." -- might be getting time for a
TV change, unfortunately. Too bad ... I expected this $$$ Sony to last
15+ years like my previous Sony CRT TVs.

-Brian
 
Heres the service manual in PDF:
http://www.mediafire.com/?bdzzit1ytte_


You might want to try some freeze spray on the flat pack IC's on the signal
board. Something tells me though its probably some SMD electrolytic caps
that are dried out somewhere.
 
Circuit wrote:
Heres the service manual in PDF:
http://www.mediafire.com/?bdzzit1ytte_
Click to expand...
Thanks! There's no troubleshooting table in it, unfortunately, other
than for blinking lights.

You might want to try some freeze spray on the flat pack IC's on the
signal board. Something tells me though its probably some SMD
electrolytic caps that are dried out somewhere.
Click to expand...
Interesting. Here's a pic of a suspicious capacitor (with gray plastic
blob next to the large capacitor in the center of the pic):

http://www.networksplus.net/standingwater/tv4.jpg

The grey blob looks factory-applied to me, and is hard. What does a
leaking capacitor look like usually?

Thanks,
Brian
 
Brian wrote:
Circuit wrote:
Heres the service manual in PDF:
http://www.mediafire.com/?bdzzit1ytte_

Thanks! There's no troubleshooting table in it, unfortunately, other
than for blinking lights.

You might want to try some freeze spray on the flat pack IC's on the
signal board. Something tells me though its probably some SMD
electrolytic caps that are dried out somewhere.

Interesting. Here's a pic of a suspicious capacitor (with gray plastic
blob next to the large capacitor in the center of the pic):

http://www.networksplus.net/standingwater/tv4.jpg

The grey blob looks factory-applied to me, and is hard. What does a
leaking capacitor look like usually?

Thanks,
Brian
Click to expand...
Just pulled out the big/wide circuit board platform (held in with only
three screws!) a bit, and don't see any capacitors that are bulged or
have black/brown staining under them.

-Brian
 
Thats RTV placed in there at the factoty. The caps I am thinking of are
silver low profile SMD electrolytics. I dont really know if your TV has
them, perhaps not since its a PJTV.
 
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