Sony Bravia KLV-32BX320 dead

[Fengo]

Hi there, I got a bravia klv-32bx320 from a friend that's completely dead. Apparently their was a powersurge at his house that left the tv dead.
I did some test with a multimeter and cant find any voltages on CN6401 and CN6402. Main fuse is ok though.
Any help will be greatly appreciated.
Thank you

[selldoor]

Re: Sony Bravia KLV-32BX320 dead

Good - thought it was your friend that was completely dead.
Really need a picture of the bottom of the board.

Find the solder joints for that BIG capacitor. With only that board connected
plug into the mains and carefully test the voltage on that big cap.
CAREFULLY - mains voltage or more - meter on vDC600.
Work on a non conductive surface and dont touch anything else on the board.

[Fengo]

Re: Sony Bravia KLV-32BX320 dead

Voltage on the big cap cycles between 303 and 307.

[selldoor]

Re: Sony Bravia KLV-32BX320 dead

ok have you tested the small yellow fuse 7a top left corner top side

[Fengo]

Re: Sony Bravia KLV-32BX320 dead

Yes I did and it tested good

[selldoor]

Re: Sony Bravia KLV-32BX320 dead

pity I love a blown fuse can you test if there is any voltage on it relative to the
ground point up and left from it.

Next -i am guessing its zero !! With no power to the board can you test the resistor to the left of the big cap with 100 on it. Do a voltage test on it first to make sure the big cap has discharged)
What is the part number of ic 6101

[Fengo]

Re: Sony Bravia KLV-32BX320 dead

Yes zero voltage on fuse. Tested resistor R6102 and no reading on it at all, IC6101 part number is MIP2H2

[selldoor]

Re: Sony Bravia KLV-32BX320 dead

No reading on the resistor?? Ohms?? try a higher /lower scale.
may have to lift one leg off the board to be sure. What does it say on it I could only read the 100

[Fengo]

Re: Sony Bravia KLV-32BX320 dead

Tried that and the one leg was lifted from board. Only printed 10 ohms J on it.

[selldoor]

Re: Sony Bravia KLV-32BX320 dead

Well I think that is a fusible resistor I think it should have resistance.

With the board powered up can you test the voltage on it with respect to the negative leg of the BIG Cap - CAREFULLY.

[budm]

Re: Sony Bravia KLV-32BX320 dead

That is 10 ohms fusible resistor for feeding B+ to the SMPS IC MIP2H2, so you need to check the resistance between pin 5 and 7-8 to see if the MOSFET inside is shorted out or not.
Service manuals:
http://elektrotanya.com/?q=showresul...oria=&kat2=all

[Fengo]

Re: Sony Bravia KLV-32BX320 dead

@selldoor, there is no voltage passing through it
@budm, can't find any resistance reading on that legs

[selldoor]

Re: Sony Bravia KLV-32BX320 dead

I thought it was connected to the BIG cap? if you have voltage on the big cap then there should be voltage on one side?

When you say no resistance on the IC do you mean it reads 0.00 ohms or is it out of range/ What range is your meter on. what does your meter show when you hold the probes together. If it is the same as the test on the legs then it is shorted

[Fengo]

Re: Sony Bravia KLV-32BX320 dead

@ selldoor, the one leg is connected to the +side of cap so it has voltage on that leg but not the other. Multimeter does not read 0.00 ohms, its a dmm so reading does not change, so I think IC is not shorted. Meter is set on 20k ohm and show 0.00 ohms when probes are held together and 1 when not.

[selldoor]

Re: Sony Bravia KLV-32BX320 dead

Ok well I reckon the fusible resister has gone - problem is we dont know why - I think that is what budm was testing the ic for.
As far as testing the IC the meter HAS to have some reading on the legs whether it is 0.00ohms 30 ohms or "1" indicating open link or off scale so what does it show?

[Fengo]

Re: Sony Bravia KLV-32BX320 dead

It remains on 1

[selldoor]

Re: Sony Bravia KLV-32BX320 dead

ok - they are not shorted - suggest you wait until budm responds - not much point replacing the resistor if its just going to blow again

[Fengo]

Re: Sony Bravia KLV-32BX320 dead

Ok thank you selldoor

[budm]

Re: Sony Bravia KLV-32BX320 dead

I was looking to see if the MOSFET inside the IC has shorted out between Source and Drain, if you are sure that it shows '1' on the meter, then the IC may be OK or the MOSFET inside has blown open circuit before the resistor went open. I am leaning toward bad IC at this point, you can try another resistor in place.

[Fengo]

Re: Sony Bravia KLV-32BX320 dead

Replaced resistor and still no voltage at CN6401