I'm working on the above mentioned set for someone. Symptom is no
picture, sound is fine. At first it was intermittent and would respond
to smacking it but now it doesn't, as is usually the case the owner
continued to use it for about 9 months until it quit entirely.

CRT heaters glow, some HV is present as indicated by a small pop when I
discharged it immediately after shutting it off, however the HV appears
to be low and doesn't make the usual static sound when turned on. I
forgot to take my HV probe with me when I was out there so I couldn't
verify this though. I did touch up a few suspect joints, checked the
semiconductors in the horizontal/HV section and didn't find anything
suspicious. I'm planning on taking another look at it but bringing the
HV probe but that'll have to wait a few days. Also there's a gray block
connected between the flyback and the tube, at first I thought it was a
doubler but then I realized there's no ground connection, no connections
of any sort other than the red wire going in and another coming out.
What function does this serve?

"James Sweet" wrote in message
news:ctlZf.18926$Py4.9853@trnddc06...
I'm working on the above mentioned set for someone. Symptom is no
picture, sound is fine. At first it was intermittent and would respond
to smacking it but now it doesn't, as is usually the case the owner
continued to use it for about 9 months until it quit entirely.

CRT heaters glow, some HV is present as indicated by a small pop when I
discharged it immediately after shutting it off, however the HV appears
to be low and doesn't make the usual static sound when turned on. I
forgot to take my HV probe with me when I was out there so I couldn't
verify this though. I did touch up a few suspect joints, checked the
semiconductors in the horizontal/HV section and didn't find anything
suspicious. I'm planning on taking another look at it but bringing the
HV probe but that'll have to wait a few days. Also there's a gray block
connected between the flyback and the tube, at first I thought it was a
doubler but then I realized there's no ground connection, no connections
of any sort other than the red wire going in and another coming out.
What function does this serve?

Are you sure about that model number? I cannot find any info on the web
about it.

--
David Farber
David Farber's Service Center
L.A., CA

David Farber wrote:
"James Sweet" wrote in message
news:ctlZf.18926$Py4.9853@trnddc06...

I'm working on the above mentioned set for someone. Symptom is no
picture, sound is fine. At first it was intermittent and would respond
to smacking it but now it doesn't, as is usually the case the owner
continued to use it for about 9 months until it quit entirely.

CRT heaters glow, some HV is present as indicated by a small pop when I
discharged it immediately after shutting it off, however the HV appears
to be low and doesn't make the usual static sound when turned on. I
forgot to take my HV probe with me when I was out there so I couldn't
verify this though. I did touch up a few suspect joints, checked the
semiconductors in the horizontal/HV section and didn't find anything
suspicious. I'm planning on taking another look at it but bringing the
HV probe but that'll have to wait a few days. Also there's a gray block
connected between the flyback and the tube, at first I thought it was a
doubler but then I realized there's no ground connection, no connections
of any sort other than the red wire going in and another coming out.
What function does this serve?


Are you sure about that model number? I cannot find any info on the web
about it.



Yes, I'm looking at a photocopy of the service manual right in front of
me, it also lists chassis SCC-S47B-A, of course the schematics are so
small they're illegible and there's really not much useful information
other than alignment stuff.

That is the H stat box, I believe that sony uses for trinitron models
in older models they use to put a control in it but later they put the
control on the CRT card.

You have to look for a bad capacitor on the screen supply, if the
screen supply isn't high enough the Guns on the CRT don't put out
beams to the screen. There are other things that could cause loss of
screen supply but that is the most common. The cap for the screen
supply is usually on the CRT card and is usually a 250 WVDC
electrolytic. This is a flyback based supply so measuring the voltage
may not give you a true reading unless you scope it.

Lastly now many times does the timer/sleep light flash when you first
turn it on? Loss of vertical scan will flash the the light 4 times if I
recall. If there is no vertical scan the set will kill the video so
that a line won't get burnt into the screen.

Good luck
KC8OJU
Raymond Borowiak