VIZIO VA26LHDTV10T - No display

[dubcostanza]

I recently acquired this TV in it's current condition, the previous owner told me that the TV had white screened and he heard a buzzing sound in it before it went out.

At this moment, when turned on the screen shows no display, but the Vizio logo lights up in a white color.

After no obvious signs of bad caps on the boards, I checked all the connections with a multimeter. I found that the connector from the power board to the main board wasn't reading the correct voltage on two pins. The two pins labeled 24v seemed to read correctly, but the two labeled 12v both read 2.76v on the main board and the power board.

I checked the key board and it read 3.29v, im not sure if this is the correct voltage, because it is not labeled and ive been unable to find a service manual.

I checked the screen with a flashlight to see if the inverter board was not lighting up, I could see nothing.

The voltage from the power to the inverter reads correct on all pins.

I've attached pictures of the connection between the main board and the power board, the power board itself, and the main board itself.

What's my next step? Thanks in advance.

[budm]

Re: VIZIO VA26LHDTV10T - No display

The connector for the 24V for feeding the inverter board, you do have 24V, but do you have BL_ON (Inv_on, or on/off)? You can see the printing next to that connector, report the reading on those pin when TV is in standby, and when it is on..
Pictures of the inverter board? Read my guide under my signature to find out how typical LCD TV works.

[dubcostanza]

Re: VIZIO VA26LHDTV10T - No display

Thanks for the reply!


Yes, I'm getting the 24v from the power board to the inverter.

I'm getting 37mV from the bl_on when I have the power cord connected, I'm guessing this is in standby, and the tv is not turning on at all. I will get a picture of the inverter when I get home from work.

[budm]

Re: VIZIO VA26LHDTV10T - No display

"At this moment, when turned on the screen shows no display, but the Vizio logo lights up in a white color." So what do you get at BL_ON when the VIZIO logo is white?

[dubcostanza]

Re: VIZIO VA26LHDTV10T - No display

When I plug it up to the power supply the vizio logo immediately lights up, and I read 36mV. When I said "on" I just meant it was plugged into the wall. Sorry for the confusion.

Ill read it again when I get home, and press the power button to see if it changes reading, but so far the power button has been unresponsive. (No clicks, nothing trying to start)

[dubcostanza]

Re: VIZIO VA26LHDTV10T - No display

Confirmed. The BL_ON reads the same before and after pressing the on button.

[budm]

Re: VIZIO VA26LHDTV10T - No display

That means the main board is the problem, it is not sending out the BL_ON to turn on the backlights.
There are many 3-legs voltage regulators on the main board that should be checked. Please go to the link under my signature to learn how to test them.

[dubcostanza]

Re: VIZIO VA26LHDTV10T - No display

Thank you for your assistance, sir. I sincerely appreciate it.

I will update you with my results.

[dubcostanza]

Re: VIZIO VA26LHDTV10T - No display

I've collected readings from the regulators, according to the video, they seem to be good?

I've attached photos, as well as the readings I found.


First photo -

U151 -> pcb designation
L1117 -> line 1 of the IC
33 -> line 2 of the IC
GK1FV913 -> line 3 of the IC
pin 1 = 0.00
pin 2 = 3.30
pin 3 = 5.08
tab = 3.3 -> incase you need


U154 -> pcb designation
L1117 -> line 1 of the IC
GKO41913 line 2 of the IC
pin 1 = 0.01
pin 2 = 1.25
pin 3 = 2.49
tab = 1.25 -> incase you need

U153 -> pcb designation
L1117 -> line 1 of the IC
GKO41913 line 2 of the IC
pin 1 = 1.25
pin 2 = 2.49
pin 3 = 4.36
tab = 2.49 -> incase you need

Second photo -

U150 -> pcb designation
17-33L -> line 1 of the IC
pin 1 = 0.00
pin 2 = 3.30
pin 3 = 5.08
tab = 3.3 -> incase you need

U152 -> pcb designation
17-33L -> line 1 of the IC
pin 1 = 0.00
pin 2 = 3.30
pin 3 = 5.11
tab = 3.3 -> incase you need

[dubcostanza]

Re: VIZIO VA26LHDTV10T - No display

Any suggestions on where I should check next?

[budm]

Re: VIZIO VA26LHDTV10T - No display

They all look OK, no more suggestion yet at this point.

[martyparish]

Re: VIZIO VA26LHDTV10T - No display

There is a cheap main board on ebay right now. $24.95 w/ free shipping.

http://www.ebay.com/sch/i.html?_odkw...+main&_sacat=0

[dubcostanza]

Re: VIZIO VA26LHDTV10T - No display

Thanks Marty, I appreciate you letting me know.