SONY BRAVIA 40WE663 odd problem

[Questcom]

Re: SONY BRAVIA 40WE663 odd problem

Guys what would cause the scaler board voltages to be missing (intermittent) if not the capacitors.Would be the DC-DC IC?
I have been reading alot about this and watching videos but most are in Hindi language and most seem to use jumpers to provide voltage.

maybe a dry joint somewhere, also worth spraying the dc to dc ic with freezer spray to see if voltages stay longer or come back

what are the input voltages measuring like when other voltages are missing
I'm still new to this but you should have 12v and maybe 3.3v on input from MB

[vikivng]

Re: SONY BRAVIA 40WE663 odd problem

Guys what would cause the scaler board voltages to be missing (intermittent) if not the capacitors.Would be the DC-DC IC?
I have been reading alot about this and watching videos but most are in Hindi language and most seem to use jumpers to provide voltage.

[vikivng]

Re: SONY BRAVIA 40WE663 odd problem

Im sure in the hands of someone experienced this is a very easy fix haha.
Im guessing the fauly lies between the first VIN and the second VIN?

[vikivng]

Re: SONY BRAVIA 40WE663 odd problem

Ok now the voltages have gone again.
VIN=12V
VCC=3.3V
right after lvds connector.

further up the board: ( I have posted pics to show areas)
VIN=0V
VDD=0V

VCC=1.8V
VONE=0V

[vikivng]

Re: SONY BRAVIA 40WE663 odd problem

Guys,
all I can say is I have absolutely no idea what happened just now.
I took voltages and was just about to post them. VONE and VDD WERE MISSING COMPLETELY.
I didnt want to post incorrect info so I went back to double check just as I was about to sit at the pc.
I rechecked VONE and was shocked to see 27.5v suddenly appear.
I looked at the screen and now the set is working.
The only thing I did was to resolder that inductor.
What could it have been.???

[diif]

Re: SONY BRAVIA 40WE663 odd problem

Measure on the test points. The tiny gold circles.

[vikivng]

Re: SONY BRAVIA 40WE663 odd problem

VONE eg.

[vikivng]

Re: SONY BRAVIA 40WE663 odd problem

OK GUYS THNX,,
have been out all day but have watching all the videos I can..I understand a bit more now.
One thing I have to ask is pinpointing the various points relevant to the V labels.
Is there a general rule.
In the photo with the VONE LABEL do I test the small capacitor ? Or is it anywhere on that large track the label sits on.?

[Questcom]

Re: SONY BRAVIA 40WE663 odd problem

Makes sense.Good thing I kept the part as I will now resolder to the board.
Any other ideas as to what would give me image for secs then amps dropping then image goes away.?
Im not sure what to check now.

I'm still learning, but I was going to say check vone and voffe voltages should be around 30v and -8v and make sure they are stable

[nomoresonys]

Re: SONY BRAVIA 40WE663 odd problem

Ok, here's what to look for testing the driver board, a video explains it a lot easier than words can: https://www.youtube.com/watch?v=Nh1ZjtI7KK8

[vikivng]

Re: SONY BRAVIA 40WE663 odd problem

well that cap turned out to be an inductor which has been replaced as it wasnt actually a faulty part.

[nomoresonys]

Re: SONY BRAVIA 40WE663 odd problem

Well if none of the other caps on the driver board are reading bad, replace the bad one, it may be the only problem or did you already replace it?

[vikivng]

Re: SONY BRAVIA 40WE663 odd problem

tested out of circuit
good state: inductor should be short and capacitor should be open
bad state: inductor would be open and capacitor short (maybe discoloured due to heat)

Makes sense.Good thing I kept the part as I will now resolder to the board.
Any other ideas as to what would give me image for secs then amps dropping then image goes away.?
Im not sure what to check now.

[Questcom]

Re: SONY BRAVIA 40WE663 odd problem

tested out of circuit
good state: inductor should be short and capacitor should be open
bad state: inductor would be open and capacitor short (maybe discoloured due to heat)

[vikivng]

Re: SONY BRAVIA 40WE663 odd problem

Ok just tested again the 3 on the mainboard and they do all test as short so Im guessing they must be inductors.

[nomoresonys]

Re: SONY BRAVIA 40WE663 odd problem

Right, make sure it is a cap, you should see a C somewhere beside the cap, L for inductor. Ok, I see now that they are not marked at all.

[vikivng]

Re: SONY BRAVIA 40WE663 odd problem

looks more like a inductor to me and not a capacitor

Aah interesting. Can anyone else confirm this part is NOT a capacitor.?
How would one tell the difference.Google images confirm they do look very similar.

[vikivng]

Re: SONY BRAVIA 40WE663 odd problem

here is a pic of the caps on the mainboard that test short albeit in circuit.

[nomoresonys]

Re: SONY BRAVIA 40WE663 odd problem

If those caps on the mainboard are testing short with NO other boards hooked up to it, remove one and test it and also test the other one while still on the board, you need to track down this short.

[Questcom]

Re: SONY BRAVIA 40WE663 odd problem

Thnx for replying.
this cap is testing short. I am assuming this should not be showing as such.?
Could this be the issue.?
Also getting 00v at both legs of that cap when power is on.
Looks like the culprit.?

looks more like a inductor to me and not a capacitor