Sharp LC-32SB24U won't turn on

[Malachi]

I have a sharp LC-32sb24u. The power light flashes once then the opc and the power led flash once at the same time.
So 2 power, 1 opc.
I'm not sure exactly how to read the service manual or what it means.
It says for 2 led flashes refer to "power failure details".
For 1 opc flash it says DET_POW1 (pin34). Main converter 13V/UR10V is not applied.

[budm]

Re: Sharp LC-32SB24U won't turn on

Can you upload the service manual?

[Malachi]

Re: Sharp LC-32SB24U won't turn on

Here is a picture curtesy of shopjimmy.
I get 5.14V for BU5V, 3V for on when I press the power button.
I get almost 9V for the 4 pins labeled 13V when I press the power button, then they slowly decrease.

[budm]

Re: Sharp LC-32SB24U won't turn on

Did you hear the relay RL7101 click on and then click off?

[Malachi]

Re: Sharp LC-32SB24U won't turn on

Yes, the relay clicks. Here is the service manual. The manual is 22.5mb over the 19mb limit. I had to compress it.
I also get about 400V on the main cap.

[Malachi]

Re: Sharp LC-32SB24U won't turn on

Picture of the back of the psu/inverter

[dick_barton]

Re: Sharp LC-32SB24U won't turn on

Can you get the supply voltages up when you jumper PS_ON to STBY with the main board disconnected.

[Malachi]

Re: Sharp LC-32SB24U won't turn on

Should I use a resistor like you had me do before?

[Malachi]

Re: Sharp LC-32SB24U won't turn on

I don't see standby.

[budm]

Re: Sharp LC-32SB24U won't turn on

The error code you reported is telling you that the IC2002 UCOM Pin 34 (DETPOW1_DET_13V) is not sensing the 13V from the power supply board.
See section 10-9, 10-17 diagram.
So if you leave the black probe on the chassis and the red probe on the 13V pin of the power supply connector and then turn the TV ON, do you see the DCV jump up at all?

[budm]

Re: Sharp LC-32SB24U won't turn on

I don't see standby.

BU5V is the standby output pin.

[budm]

Re: Sharp LC-32SB24U won't turn on

BTW, what dcv do you have at the AC DET pin?

[Malachi]

Re: Sharp LC-32SB24U won't turn on

The error code you reported is telling you that the IC2002 UCOM Pin 34 (DETPOW1_DET_13V) is not sensing the 13V from the power supply board.
See section 10-9, 10-17 diagram.
So if you leave the black probe on the chassis and the red probe on the 13V pin of the power supply connector and then turn the TV ON, do you see the DCV jump up at all?

Yes , to around 8V.

[Malachi]

Re: Sharp LC-32SB24U won't turn on

BTW, what dcv do you have at the AC DET pin?

Nothing. I reported all the voltages I get.

[Malachi]

Re: Sharp LC-32SB24U won't turn on

So do I use a resistor between BU5v and ps_on? I jumped the two without a resistor and the relay clicked.

[budm]

Re: Sharp LC-32SB24U won't turn on

Yes , to around 8V.

Well, that is not good then, the PFC is working since you are getting the 400VDC on the main cap, so something in the 13V supply is not working.

[Malachi]

Re: Sharp LC-32SB24U won't turn on

So, do you think a working board would fix it?

[budm]

Re: Sharp LC-32SB24U won't turn on

Probably if there is no other problem in other section.
Power supply SCH, hopefully will match your board.
Check the capacitance of capacitor C7142 (0.22uF).
Check D7201, 7203.

[Malachi]

Re: Sharp LC-32SB24U won't turn on

I'm not getting any capacitance reading on C7142. Still trying to find the diodes.
D7201 and 7203 are not shorted. D7203 reads in the K's ohm, D7201 in the hundreds.

[budm]

Re: Sharp LC-32SB24U won't turn on

Remove that cap and take the reading, if that cap loses its capacitance then you will not get full output Voltage on the secondary side.