vizio vf55 power surge

[scottafl]

I have a Vizio VF550XVT1A - Had a pretty good lighting storm today TV was on and power cycled very quickly, "VIZIO" flickers continually, unplugged for 10 min. no help. everything i have read online says the main board needs to be replaced - main board 3655-0012-0150(2B)

I am good with a soldering iron but only have multi-meter. I am willing to replace the board but would like to be certain it is the problem. 5V to main board is good.

Any help would be greatly appreciated, don't mind smart asses...

[scottafl]

Re: vizio vf55 power surge

Need some help guys! please let me know if you need more info...thx!

[t.j.]

Re: vizio vf55 power surge

did ya check fuses?

[multimeter]

Re: vizio vf55 power surge

first steps would be to check fuses, output voltages on the psu,large cap should be around 3-4 x your line voltage,if no output voltages present,check bridge,transient diodes (if any),varistor,if these check good,and psu voltages are good,then most likely ,a spike has fried the cpu on the main board

[scottafl]

Re: vizio vf55 power surge

here are some pics of the main board

[tom66]

Re: vizio vf55 power surge

There are two fuses near the power connector. With the metal caps on the end. Check if they are okay.

[scottafl]

Re: vizio vf55 power surge

thanks for responses, and patients!! fuse is good. large cap is shielded is there a test point for this puppy?

[tom66]

Re: vizio vf55 power surge

What's the voltage on each end of the fuse, with the black probe grounded to the case of the TV?

[scottafl]

Re: vizio vf55 power surge

found 1 fuse near pwr connector it is good, here is pic of the power board and another of the main board

[scottafl]

Re: vizio vf55 power surge

124 ac on both ends of fuse

[tom66]

Re: vizio vf55 power surge

Sorry - miscommunication - I meant test voltage on mainboard fuses.

[scottafl]

Re: vizio vf55 power surge

1 is 5vdc the other is less than .1vdc. s/b 24vdc correct?

[tom66]

Re: vizio vf55 power surge

So you have your problem here, 5V standby is up (hence Vizio logo working), but 12V is dead. Probably 24V too. Is there a pin marked PSON on power supply?

[scottafl]

Re: vizio vf55 power surge

F1 is 5.04/4.89 vdc F2 is .0036/.0034

[scottafl]

Re: vizio vf55 power surge

Yes CF5 - should i remove connector and check voltage?

[scottafl]

Re: vizio vf55 power surge

should the 12 and 24v be on to the main board with plugged in power off?? pressing power switch does nothing.

[scottafl]

Re: vizio vf55 power surge

PSON assume this is PWR ON correct? does it need 5vdc jump to power up power up power board?

[scottafl]

Re: vizio vf55 power surge

hey guys just need to diagnose to board level. is this the main board or the power board??

[scottafl]

Re: vizio vf55 power surge

hello is there anybody out there

[scottafl]

Re: vizio vf55 power surge

just node if you can hear