Vizio vw42lfhdtv

[budm]

Re: Vizio vw42lfhdtv

I jump the p_s on and got 12v and 24v but didn't get a blue screen or was I suppose to get a blue screen.

it needs BL_ON signal, on the connector between the power supply and the inverter board there should be three pins labeled as A, B, and C. I do not remember which one is BL_ON and which one is dimming control.
It may be easier to locate the BL_ON pin on the inverter board, it should be >2.5VDC for backlights on.
What is the P/N of U44?
So right now after the cap is replaced you still do not have PS_ON?

[fixerupper75]

Re: Vizio vw42lfhdtv

it needs BL_ON signal, on the connector between the power supply and the inverter board there should be three pins labeled as A, B, and C. I do not remember which one is BL_ON and which one is dimming control.
It may be easier to locate the BL_ON pin on the inverter board, it should be >2.5VDC for backlights on.
What is the P/N of U44?
So right now after the cap is replaced you still do not have PS_ON?

A=.125
B=.030
C=no pin

U44 part no. k021 G9117
That's right after replacing the cap still no ps_on.

[budm]

Re: Vizio vw42lfhdtv

OK, you do not have BL_ON or dimming signal either, the U44 will not have any voltage until the main power supply is turned on by the main board.
At this point you will need new main board.

[fixerupper75]

Re: Vizio vw42lfhdtv

OK, you do not have BL_ON or dimming signal either, the U44 will not have any voltage until the main power supply is turned on by the main board.
At this point you will need new main board.

Ok thanks for all the help!!! I will keep you posted.

[nomoresonys]

Re: Vizio vw42lfhdtv

must be a little different than a sony, when my mainboard was disconnected from power supply the backlights popped right on.

[budm]

Re: Vizio vw42lfhdtv

It depends on if the power supply board has build-in pull up resistors for the PS_ON and the BL_ON or not, most of the newer SAMSUNG and SONY have pull-up resistors now for easier diagnostic.

[nomoresonys]

Re: Vizio vw42lfhdtv

It depends on if the power supply board has build-in pull up resistors for the PS_ON and the BL_ON or not, most of the newer SAMSUNG and SONY have pull-up resistors now for easier diagnostic.

Thanks for clarification budm, had me puzzled.

[fixerupper75]

Re: Vizio vw42lfhdtv

Replaced the main board and Bam.....We have life!!!! Thank to all my first dumpster save.

[budm]

Re: Vizio vw42lfhdtv

Thanks for the repair feedback.
You should record all the Voltage reading on the power supply board, main board when TV is off and when TV is on so you will know what they should be.