Dead As A Doornail. Sony KDL-40EX400

[Michale32086]

Re: Dead As A Doornail. Sony KDL-40EX400

Checking all the pins with the cable connected gives me the 3.3v on standby.. I am guessing when I checked them before I wasn't making contact with the pin, as I was just using the probe tip..

This time around, I used a straight pin hooked to the probe to insure contact...

[budm]

Re: Dead As A Doornail. Sony KDL-40EX400

"The only standby I could find was 3.3v

Checked the marked pin and it did give me 3.3v at plug in"
So you are saying that there was no Voltage what so ever when all the boards are connected, and now you do have 3.3VSTBY when the cables are disconnected from the power supply board.

[Michale32086]

Re: Dead As A Doornail. Sony KDL-40EX400

Yea, Tom's idea might shed light on that. But it will have to wait til I get to the shop.. I have no resistors here at home..

[nomoresonys]

Re: Dead As A Doornail. Sony KDL-40EX400

dunno, it seems like the mainboard isnt turning on the power supply.

[Michale32086]

Re: Dead As A Doornail. Sony KDL-40EX400

You can usually check power supply operation by connecting STBY and POWER ON with a small resistor (100 to 470 ohms, 1/4W through hole type)

Lemme see if I can dig up a resistor..

[Michale32086]

Re: Dead As A Doornail. Sony KDL-40EX400

ok, now is that with all the boards plugged in?

It was out.. But here are the voltages with the connector plugged in..

All the unmarked pins are 0v

[nomoresonys]

Re: Dead As A Doornail. Sony KDL-40EX400

The pins outlined in red have 3.3v

All the other pins (black) have 0v

ok, now is that with all the boards plugged in?

[Michale32086]

Re: Dead As A Doornail. Sony KDL-40EX400

The pins outlined in red have 3.3v

All the other pins (black) have 0v

[tom66]

Re: Dead As A Doornail. Sony KDL-40EX400

You can usually check power supply operation by connecting STBY and POWER ON with a small resistor (100 to 470 ohms, 1/4W through hole type)

[nomoresonys]

Re: Dead As A Doornail. Sony KDL-40EX400

thats good, are your other voltages correct too?

[Michale32086]

Re: Dead As A Doornail. Sony KDL-40EX400

maybe try unplug the connector from power supply that has stndby, and measure the stndby pin on power supply in dc mode.

The only standby I could find was 3.3v

Checked the marked pin and it did give me 3.3v at plug in

[nomoresonys]

Re: Dead As A Doornail. Sony KDL-40EX400

maybe try unplug the connector from power supply that has stndby, and measure the stndby pin on power supply in dc mode.

[Michale32086]

Re: Dead As A Doornail. Sony KDL-40EX400

I seem to remember a problem before similar to this where the MainBoard was the culprit..

[tom66]

Re: Dead As A Doornail. Sony KDL-40EX400

Yes, since this PSU uses Active PFC, the cap voltage will boost (typically to 380-400V)

[nomoresonys]

Re: Dead As A Doornail. Sony KDL-40EX400

wonder if this could be a bridge rectifier issue?

[nomoresonys]

Re: Dead As A Doornail. Sony KDL-40EX400

Yea, should have clarified that..

That's what I get when I plug the TV in.. Pushing the power button has no effect.. Still reads 166v

I think when its working right its suppose to jump to 390 or so.

[Michale32086]

Re: Dead As A Doornail. Sony KDL-40EX400

Yea, should have clarified that..

That's what I get when I plug the TV in.. Pushing the power button has no effect.. Still reads 166v

[nomoresonys]

Re: Dead As A Doornail. Sony KDL-40EX400

OK, I get 166V on the large cap which is a 270uf 450V cap...

I think that sounds about right, is that with tv off?, does it go up when you turn tv on?

[Michale32086]

Re: Dead As A Doornail. Sony KDL-40EX400

OK, I get 166V on the large cap which is a 270uf 450V cap...

[Michale32086]

Re: Dead As A Doornail. Sony KDL-40EX400

So you get 0 Volt on all the pins of the the connector of the power supply that goes to to the main board?
How about the pictures of the whole back side of the TV so we can see how all the boards are connected together?

Nope, no power on either of the connectors...

I also am ready to check the voltages on the large cap.. Just wanted to make sure the setup I have (pic) is good..