Sony Wega problem (No picture)


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Sony Wega problem (No picture)

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Cativo
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Feb 21, 2006, 8:11 PM

Post #1 of 21 (8681 views)
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Sony Wega problem (No picture)	Can't Post

Hello everyone. I tried a search and found that one person had a simliar problem about 3 years ago, but no solution was ever posted.

My problem is as follows. I have a Sony Wega (KV-36XBR450) about 2 years old. I went to watch TV this morning before leaving for work and heard the TV Degauss as normal, but no picture came up. The front STDBY led blinks a few times but the TV goes back off. I tried unplugging it and leaving it off for about 20 seconds, then plug it in. No help. I do hear sound, but no picture! I was just watching TV last night and did not see anything weird???

Anyone have any ideas???

techchris
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Feb 21, 2006, 8:24 PM

Post #2 of 21 (8676 views)
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Re: [Cativo] Sony Wega problem (No picture) [In reply to]	Can't Post

count the number of flashes.it gives a clue to where the fault is. usually on sony tv's the flyback transformer is gone and has taken out the lop transistor as well

Cativo
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Feb 21, 2006, 9:30 PM

Post #3 of 21 (8670 views)
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Re: [techchris] Sony Wega problem (No picture) [In reply to]	Can't Post

I will count the flashes tonight. In case, are these parts something I can get fairly easily?

(This post was edited by Cativo on Feb 21, 2006, 10:26 PM)

Cativo
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Feb 22, 2006, 4:48 PM

Post #4 of 21 (8659 views)
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Re: [Cativo] Sony Wega problem (No picture) [In reply to]	Can't Post

Ok, so I counted the flashes and they total 4 in sequence. I tried to unplug the TV over night and I still get sound, but no picture. Then it turns itself off after about 15 seconds and starts the stby light blinking.

Any ideas???

techchris
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Feb 22, 2006, 9:10 PM

Post #5 of 21 (8653 views)
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Re: [Cativo] Sony Wega problem (No picture) [In reply to]	Can't Post

disconnect the collector pin of the lop transistor.if the ht comes up to about 160volts on the connection on the pcb you disconnected ,then the flyback tx and lop transistor are faulty

mel
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Feb 23, 2006, 12:03 AM

Post #6 of 21 (8647 views)
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Re: [Cativo] Sony Wega problem (No picture) [In reply to]	Can't Post

According to the Sony manual on this model,

"Shutdown- Standby light blinks four times

Circuit - A vertical failure because of the output IC or power supply (both on the D board) will cause the Y/C, CRT drive IC201 to send emergeny data to to main Ucom IC701. IC701 turns the TV off by opening the AC relay (IC701 pin 69 goes LOW).

Testing- Measure the +15 and -15 volts on the vertical output IC5004 pins 2 and 4 before you suspect the IC itself.

Cativo
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Feb 23, 2006, 1:18 AM

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Re: [mel] Sony Wega problem (No picture) [In reply to]	Can't Post

Awesome info. Thanks. I will check this out and report back. At this point I think it makes sense to just replace the whole D-Board. Versus shot gunning components. Ya think?

(This post was edited by Cativo on Feb 23, 2006, 1:26 AM)

mel
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Feb 23, 2006, 11:38 PM

Post #8 of 21 (8634 views)
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Re: [Cativo] Sony Wega problem (No picture) [In reply to]	Can't Post

It would be a lot easier but a lot more expensive. I would first check the voltages and if OK, replace the vertical output IC and see if that fixes it. You are looking a probably less than $10 part as apposed to the much more expensive complete board.

Cativo
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Feb 24, 2006, 12:04 AM

Post #9 of 21 (8632 views)
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Re: [mel] Sony Wega problem (No picture) [In reply to]	Can't Post

So I do have one question. Is this the vertically mounted pcb (pretty large in size) that is mounted to the motherboard and back rca connection accesory panel? I ordered a D-board, but it could be weeks before I get it, so I have time to try and fix this board.

mel
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Feb 24, 2006, 12:10 AM

Post #10 of 21 (8630 views)
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Re: [Cativo] Sony Wega problem (No picture) [In reply to]	Can't Post

It is the one with the flyback transformer mounted on it.

Cativo
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Feb 24, 2006, 1:20 AM

Post #11 of 21 (8629 views)
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Re: [mel] Sony Wega problem (No picture) [In reply to]	Can't Post

Oh, ok. Thanks!

Cativo
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Feb 24, 2006, 5:57 PM

Post #12 of 21 (8620 views)
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Re: [Cativo] Sony Wega problem (No picture) [In reply to]	Can't Post

My D-Board arrives tonight, so I guess I will swap that out this evening and give it a whirl. So, I take it I have to remove the flyback transformer. I know that is the area that is most HOT, so does anyone have any suggestion before I dig into this board? Safety wise, I guess. I have worked on many electronics items in the past, but it never hurts to check with people who have dealt in the area more times then I. Experience is worth its weight in GOLD! Any info would be wonderful guys!

mel
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Feb 24, 2006, 11:27 PM

Post #13 of 21 (8613 views)
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Re: [Cativo] Sony Wega problem (No picture) [In reply to]	Can't Post

Actually, the board should be intact and all you should have to do is uplug the old one and plug in the new. You will have to disconnect the high voltage lead from the back of the CRT where you shloud exercise caution and discharge the residual high voltage stored in the CRT. Just use a flat bleded screw driver and a jumper wire to do this. Connect one end of the jumper wire to the mesh grounding strap on the back of the tube and the other end to the blade of the screw driver. Being careful not to touch the screwdriver blade, insert it under the rubber cap of the red CRT lead. You should hear a crack as the high voltage arcs to ground.

Cativo
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Feb 25, 2006, 12:00 AM

Post #14 of 21 (8606 views)
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Re: [mel] Sony Wega problem (No picture) [In reply to]	Can't Post

Great, thanks!

Cativo
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Feb 25, 2006, 4:21 AM

Post #15 of 21 (8601 views)
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Re: [Cativo] Sony Wega problem (No picture) [In reply to]	Can't Post

Ok, so I got the D-Board and was able to install it with minimal problems (just a pain in arse to get it in and out of there). Plugged everything in again and made sure all was snug. Powered TV on, and got the exact same thing. TV came on, sound came on, but no picture. Then aver a few seconds (maybe 15-20) the TV shut itself off and did the 4 blink pattern. Could I have gotten a bad board with a similiar problem? Bough the board from partstore.com and had it overnighted, sy they were good about getting it to me fast. Though the board did have dust spread across portions of it which tells me that it was in fact used, but I would like to think tested?

Any thoughts from the guru's? This stinks! All the effort for nothing. LOL.

(This post was edited by Cativo on Feb 25, 2006, 6:10 AM)

mel
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Feb 25, 2006, 11:03 PM

Post #16 of 21 (8582 views)
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Re: [Cativo] Sony Wega problem (No picture) [In reply to]	Can't Post

The only other possible link that I see is the IC201 on th e A board.

Cativo
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Mar 1, 2006, 4:46 PM

Post #17 of 21 (8566 views)
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Re: [mel] Sony Wega problem (No picture) [In reply to]	Can't Post

Great news all. I want to personnaly thank all of you for your help here. The new D-Board fixed my TV. I guess the first one I recieved was a bad one, so when I got the new one last night I plugged it in and away we go. I sure hope it lasts a while. lol.

Anyways, thanks for all of your help!!!! Cool

Cativo
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Mar 2, 2006, 12:37 AM

Post #18 of 21 (8561 views)
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Re: [Cativo] Sony Wega problem (No picture) [In reply to]	Can't Post

My last request. LOL

Does anyone have any ideas on what to do with my faulty D Board? Is there a place to sell these things? Someone must like to repair them and make some money off of them??

Cativo
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Mar 2, 2006, 5:23 PM

Post #19 of 21 (8553 views)
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Re: [Cativo] Sony Wega problem (No picture) [In reply to]	Can't Post

Had kind of a scare last night. While I was watching TV, TV had been on about 4 hours straight, the TV powered off and I had the four blink pattern again. I unplugged it for about a minute and replugged it in and it worked again. I sure hope this board I put in is not starting to fail already. After just one day. I wonder if I need to buy a NEW board from Sony instead of these repaired ones.

Fingers crossed!!!!!

(This post was edited by Cativo on Mar 2, 2006, 5:54 PM)

rrobor
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Mar 6, 2006, 11:00 AM

Post #20 of 21 (8523 views)
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Re: [Cativo] Sony Wega problem (No picture) [In reply to]	Can't Post

Someone is fixing it by using generic parts. most times Sony needs Sony parts. So instead of paying 6 bucks for a vertical IC you pay 16 but it works. Your TV wont last Im afraid, The chip is overheating.

Cativo
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Mar 6, 2006, 6:03 PM

Post #21 of 21 (8521 views)
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Re: [rrobor] Sony Wega problem (No picture) [In reply to]	Can't Post

That is what I am afraid of. I'm sure it will die soon. I need to unload this TV. I can tell that!

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