Vizio va320m no picture

[trainhunter]

so i have a vizio va320m that appears to have a backlight issue. ive read a similar forum and have applied the trouble shooting to my tv but to no avail.

when i power the tv on the vizio light goes from amber to white but there is no picture. i put the tv in a dark room and shined a flashlight on and and saw nothing. i then checked for the proper output voltages on the power supply and all of the wires had the appropriate voltage for what was stamped on the board.

at this point im am not sure where i should do. Any advice would be greatly appreciated

[newtothis]

Re: Vizio va320m no picture

OK just to make sure.... did you have an input signal when you shone the light onto the screen?

If so then pics of boards and chassis please

[trainhunter]

Re: Vizio va320m no picture

there was no input on the screen and here are some photos. thank you for responding.

[newtothis]

Re: Vizio va320m no picture

If a tv doesn't have an input.. E.g Sky, PC, TV channel it is sometimes hard to see anything with a flashlight.

So just want to double check that with you before we get the DMM out

[budm]

Re: Vizio va320m no picture

Can you tell if the backlights flash on for seconds at all? What DC voltage do you get at the two legs of the large black cap laying on its side? Measure it right at the two legs, it should be around 370~400VDC range, be careful not to touch anything on the board with your hands or body.

[trainhunter]

Re: Vizio va320m no picture

i plugged up a dvd player and double checked with the flashlight and still nothing. i check that large black cap and it was getting 395VDC. and the backlight dosent come on at allnot even for a second

[budm]

Re: Vizio va320m no picture

OK, at least the PS_ON signal is good, same for the PFC Voltage booster circuit. So next signal we need to check is the INVERTER_ON (or BL_ON) signal, it should be >2.5VDC. If it does have the signal, then we need to do more in-depth troubleshooting the inverter circuits.

[trainhunter]

Re: Vizio va320m no picture

ok where do i check for that signal at

[budm]

Re: Vizio va320m no picture

Are there any labeling next the connector on the power supply/inverter board that goes to the main board?

[trainhunter]

Re: Vizio va320m no picture

sorry it took me so long been very busy lately. the connector is labeled cn902. next to the connector is has the voltages labeled for each of the wires on that connector and i have checked all of them and all are getting proper voltage

[budm]

Re: Vizio va320m no picture

So what DC voltage do you have at the INVR_ON (BL_ON)?

[trainhunter]

Re: Vizio va320m no picture

where is that located

[budm]

Re: Vizio va320m no picture

Post the label of the connector (cn902?) pins of the power supply board, you indicated that you get the correct voltages, but what are they labeled with?

[ChrisV]

Re: Vizio va320m no picture

when i power the tv on the vizio light goes from amber to white but there is no picture. i put the tv in a dark room and shined a flashlight on and saw nothing

I'm having a similar problem with a Vizio plasma. Will you please explain how to do the test with the flashlight and what you are checking for?