Sony 7 Blinks - Likely Cause?

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wegahv
Sony 7 Blinks - Likely Cause?

In my Kv-34hs5100, all of a sudden, not picture or sound.....been raining for 2 days.

7 blinks on the standby light indicating HV issue? 

Have an EE background but havent repaired TV for 20 years.

 Is this likely to be a board swap?

 Wish I could get a service manual for it....maybe I can repair.  Know how to make sure things are discharged, so maybe I can do it....only 4 years old.

 Any suggestions?

zapdbf
I don't have time today, but

I don't have time today, but i can try to help, this is a bump. i will post more tonight or tommarow

wegahv
Well.....the picture came

Well.....the picture came back but then went away.

 NOW it blinks 6 times instead of 7.  Looks like horizontal is common to both.

 I've got to get a service manual for this.  Then maybe I can work it.

 ANY SUGGESTIONS FOR 7 BLINKS CHANGING TO 6 BLINKS THE FOLLOWING DAY?

zapdbf
You are right you need a

You are right you need a service manual for this one!, there are too many possibilities. try www.servicemanuals.net

the 7 and 6  blink have several elements in common with each other so this is not un usuial.

Here are some suggestions to check for -

1. Flyback T8001 caused Q8013 and Q8014 to short out and
R8051 opens up.

2. B Board can load down the 5v line you may need to troublshoot this board or just replace it if you can determine this.

3. Video Output can be shorted causing over current  demand on FBT did you see a picture or was it just white.

4 if it is intermittent it could be C6590 on the D Board.

wegahv
Thanks.....a lot of great

Thanks.....a lot of great leads.....Ordering a service Manual.

Will let you know what happens next.

 Thanks again.

zapdbf
i just got a tv in with the

i just got a tv in with the exact same problem it is a kv36hs510 i just put it on my bench, i will let you know what i did.

zapdbf
ok here is a play by play for

ok here is a play by play for this set, when i plugged it in i heard the hv come up, so it looks less likely that ic8002 is faulty, next i will see if the 5 volts that is being generated by the flyback will come up for any length of time.

zapdbf
the 5 volt line comes up fine

the 5 volt line comes up fine, i tested it on pin 8 of cn5604, since the 5 volts seem to be ok, my attention returns to the hv circuit, i am now suspicious of the flyback transformer, i will remove the transformer and ring it to see if it is working like i think it should.

zapdbf
I got one ring out of the

I got one ring out of the flyback, that pretty well clinches it, The flyback has some shorted windings in it, But because the primary of the flyback was shorted(drawing too much current) there is a strong possibility that the supporting circuit has been damaged. This damage can go un detected for some time. so i want to keep the customer happy, so i am going to replace the two controlling transistors and control ic, this is a preventive measure. There is no way i can know for sure if those components are damaged, but they are relatively cheap and it is a good bet that i will not see this tv back in my shop for a long time if ever again if i take these steps.  to sum up the troubleshoot i am replacing the following parts.

ic8002

t8001

Q8013

q8014

this is a solid fix. I have seen this problem so many times.

zapdbf
finaly after allot of

finaly after allot of questions from the field i had to answer i got back on this tv, I have replaced the parts, we had them in stock, it is now playing and testing on our burn-in shelf, it will stay for 2 days to make sure nothing else crops up, then it will be delivered back to the customer.

The End ..

wegahv
Thank you so much.....I'll

Thank you so much.....I'll pursue the exact sequence.  Just got to get the 225 lb out of the furniture and onto the floor.

Thanks again....sure are lucky to have you reading these forums.

wegahv
If it is t8001 and I replace

If it is t8001 and I replace it, is there setup/adjustments/alignment to be done afterwards?

 Also, does the transformer plug in or is it soldered on to the board?

 Finally, is there a way that I can check the transformer to make sure before I replace it?

zapdbf
There is no solid menthod,

There is no solid menthod, unless you have special equipment to this buisness.

wegahv
Well, I finally got set up

Well, I finally got set up and made some measurements.  Thanks for your suggestions.....

 1st....the tv will either come up (full operation), or it will click a couple times....no HV sound, and the LED will blink 6 times....indicating +5V problem 'Shutdown'.

+5 is fine at IC504...(except that pin number 4 is at 3.4V...is it floating?).  Case/heat sink seems to be at ground.

+5UNREG is at 6V.....that was the one I measured at Pin 8 of CN6504 (I think this is what you meant).

Now I need some suggestions.  Your situation with T8002 seems like your HV would come up but  was not high enough...so your TV was 'running'  Mine does not come up because the 'safety shutoff' relay clicks in and I get nothing.....no sound or Pix.

Or maybe on the way up 5V has a hard time and sometimes comes up and sometimes doesn't.

Got any hot suggestions?

 

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