Perfect Sound but no Picture on my Sony


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Perfect Sound but no Picture on my Sony

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FixMyTv
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Aug 5, 2009, 2:15 AM

Post #1 of 11 (12726 views)
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Perfect Sound but no Picture on my Sony	Can't Post

Hey guys,

My Sony KP-48V75 rear projection tv has a black screen but the sound is ok. I tried re-seating all the connections but no luck. I can see the color come on in the projectors but there is no light. Not sure if this model has a bulb or tube? The service light is blinking non stop. Can anyone help or share service manual? Thanks in advance.

(This post was edited by FixMyTv on Aug 5, 2009, 2:26 AM)

jts1957
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Aug 5, 2009, 2:29 AM

Post #2 of 11 (12720 views)
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Re: [FixMyTv] Perfect Sound but no Picture on my Sony [In reply to]	Can't Post

Can you pull up a menu screen?
Does the set have high voltage?
Do the tubes light - front &/or filament?

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Location: Far, Far Away

FixMyTv
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Aug 5, 2009, 2:50 AM

Post #3 of 11 (12717 views)
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Re: [jts1957] Perfect Sound but no Picture on my Sony [In reply to]	Can't Post

If you're referring to the 3 projector colors I can see the colors come on but they are so faint that there is no light reaching the mirror. I don't get any picture at all. Not sure about high voltage that's why I'm trying to find manual. Thanks!

FixMyTv
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Aug 7, 2009, 8:55 PM

Post #4 of 11 (12700 views)
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Re: [FixMyTv] Perfect Sound but no Picture on my Sony [In reply to]	Can't Post

Any more tips? Thanks!
I can't find the service manual anywhere online.
I don't get any kind of video output. There is no light going to the mirror.
I was looking around but did not find if this model (Sony KP-48V75) has any bulbs?
The only ones I see are the three projectors which are barely on. But it seems like that is normal and there should be another light to advace the projector colors.
Help!!! Frown

jts1957
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Aug 8, 2009, 3:13 AM

Post #5 of 11 (12692 views)
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Re: [FixMyTv] Perfect Sound but no Picture on my Sony [In reply to]	Can't Post

If looks something like: http://img73.imageshack.us/...2976/93635680ls5.jpg
is "CRT-type" set. Wink

This is a DLP "BULB": http://www.electronicsforless.ca/...erfs/TBL4-LMP_LG.jpg

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Location: Far, Far Away

FixMyTv
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Aug 8, 2009, 6:05 AM

Post #6 of 11 (12690 views)
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Re: [jts1957] Perfect Sound but no Picture on my Sony [In reply to]	Can't Post

Thanks!

My tv is exactly like that first pic (CRT). When I turn on the tv, I can see the projection bulbs come on very low. I could bearly tell they were coming on at first that I had to clean them which didn't help much. I think there is a small driver board for the 3 lights. I was trying to figure out if there is another light involved in the video process? I noticed alot of dust inside the boards. Is it ok to spray the boards with electronics degreaser?

On CRT style, should the light from the 3 projection bulbs reach the mirror?
Cause the light is so dim it's hard to tell they are coming on at all.

jts1957
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Aug 8, 2009, 3:16 PM

Post #7 of 11 (12680 views)
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Re: [FixMyTv] Perfect Sound but no Picture on my Sony [In reply to]	Can't Post

Nope, only CRT produces the light. Does looking in the tubes show any video (with VCR/DVD/Antenna-Converter or cable) and do CRTs "stay" lit (or come up, then fade away)? How are the On Screen Displays (also dim or normal?)?
Using canned/compressed air should be sufficient to get rid of dust. As far as degreaser, why? If you must be sure set is off and allow plenty of drying time.
The three CRTs are just like a regular CRT with two exceptions: 1) One tube for each color; and, 2) Should be much brighter than regular CRT.
I don't suppose you have a way of measuring the amount of high voltage?

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Location: Far, Far Away

FixMyTv
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Aug 10, 2009, 1:37 AM

Post #8 of 11 (12670 views)
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Re: [jts1957] Perfect Sound but no Picture on my Sony [In reply to]	Can't Post

How high?
I have a digital mulitmeter.

The CRT's light up when the video is to come on. They are very faint though. I don't get any video output, not even with the atenna on, there's absolutely no picture on the screen. You can't even see the volume or anything. Completely black screen. Like I said, the audio is perfect.

jts1957
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Aug 10, 2009, 2:27 AM

Post #9 of 11 (12668 views)
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Re: [FixMyTv] Perfect Sound but no Picture on my Sony [In reply to]	Can't Post

30,000 (3KV) volts. Wink

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FixMyTv
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Aug 10, 2009, 9:55 PM

Post #10 of 11 (12665 views)
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Re: [jts1957] Perfect Sound but no Picture on my Sony [In reply to]	Can't Post

So you're saying call a tv tech? Frown

I repair electronic equipment for living so would like to give it a shot.
3KV would be 3k right?
I may have a high voltage measuring tool.

jts1957
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Aug 10, 2009, 10:54 PM

Post #11 of 11 (12663 views)
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Re: [FixMyTv] Perfect Sound but no Picture on my Sony [In reply to]	Can't Post

My bad. 30,000 volts (30Kv).

from 'Catch It and You Keep It': "Go for it, Bob! Go for it!" Wink

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(This post was edited by jts1957 on Aug 10, 2009, 10:54 PM)

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