Vizio VO47L-FHDTV10A turns on and then off (3 seconds)

[cliff_hootarski]

Re: Vizio VO47L-FHDTV10A turns on and then off (3 seconds)

1.You must measure the inverter input voltage( labeled 24v on the power supply) between 24v and SGND.(DC)
It should be 24v with the TV on and while the main filter caps measure 391volts.
If it measures 24v, you also have an inverter problem.(No backlight)

2. Not being able to turn your TV Off with the power switch indicates a main board problem as well.

[Naturallyk2]

Re: Vizio VO47L-FHDTV10A turns on and then off (3 seconds)

So I re-measured the 24v rail off the PS and both slave and master side are putting out 24v. So It looks like I'm trying to figure out why the Mainboard isn't telling the inverters to kick on (since there is no voltage on pin 13 on the main board)

[vinceroger69]

Re: Vizio VO47L-FHDTV10A turns on and then off (3 seconds)

This certainly sounds a mainboard issue did you check all the other voltage regulators for correct voltages? also i wonder if a corrupt eeprom could cause this as they can cause odd behaviour, What mainboard number is used in this set? you may have to match it to any sticker numbers too so it matches the lcd panel used in your set.

[cliff_hootarski]

Re: Vizio VO47L-FHDTV10A turns on and then off (3 seconds)

OK, the main board also sends a "backlight on" signal to the inverters. No "on" signal, coupled with the "unable to turn off the TV" problem certainly leads to a main board problem.

I suggest you try to source a replacement board.

eBay has at least one available:

item# 252404909170 $28.50 shipped.

[Naturallyk2]

Re: Vizio VO47L-FHDTV10A turns on and then off (3 seconds)

Yea, I guess I'll have to bite the bullet and try a main board replacement.

[Naturallyk2]

Re: Vizio VO47L-FHDTV10A turns on and then off (3 seconds)

This certainly sounds a mainboard issue did you check all the other voltage regulators for correct voltages? also i wonder if a corrupt eeprom could cause this as they can cause odd behaviour, What mainboard number is used in this set? you may have to match it to any sticker numbers too so it matches the lcd panel used in your set.

Vince, when you say eeprom, are you referring to the one on the mainboard? I hope so, because I just ordered a replacement mainboard today.

[vinceroger69]

Re: Vizio VO47L-FHDTV10A turns on and then off (3 seconds)

yes the eeprom is on the mainboard sometimes shopjimmy sell a pre programmed one if you look on there websiste it also tells you what faults it may fix too.

[Naturallyk2]

Re: Vizio VO47L-FHDTV10A turns on and then off (3 seconds)

Hoooooly smokes look at that. Fixed. Not sure if it was the EEPROM though. Swapped out the main board with another one and bam! It works. Will upload the picture of the back of the main board on one IC. It looks damaged from the old board.

Sidenote: The main filter cap reaches 435vdc when the TV is on. I'm not sure if that's good or bad since the cap is rated at 390vdc. Any thoughts?

[budm]

Re: Vizio VO47L-FHDTV10A turns on and then off (3 seconds)

Hoooooly smokes look at that. Fixed. Not sure if it was the EEPROM though. Swapped out the main board with another one and bam! It works. Will upload the picture of the back of the main board on one IC. It looks damaged from the old board.

Sidenote: The main filter cap reaches 435vdc when the TV is on. I'm not sure if that's good or bad since the cap is rated at 390vdc. Any thoughts?

That is not good if your meter is showing that much Voltage, do not run it like that, the feedback in the PFC circuit may be bad.

[Naturallyk2]

Re: Vizio VO47L-FHDTV10A turns on and then off (3 seconds)

I'm going to test it again with a different meter just to validate that reading. What do you mean by the PFC circuit?

[budm]

Re: Vizio VO47L-FHDTV10A turns on and then off (3 seconds)

Just search the forum for 'PFC Voltage booster'.
Or searc the web for 'PFC VOLTAGE Booster in LCD tv'
I.E.
https://cdn.badcaps-static.com/pdfs/...d13ffed70f.pdf

[Naturallyk2]

Re: Vizio VO47L-FHDTV10A turns on and then off (3 seconds)

That is not good if your meter is showing that much Voltage, do not run it like that, the feedback in the PFC circuit may be bad.

BUDM, nvm. I just used my other multimeter to validate the 430 reading and it was flawed. We are sitting at a nice 389vdc now .

[budm]

Re: Vizio VO47L-FHDTV10A turns on and then off (3 seconds)

Good, the battery is probably low in the bad meter.

[Naturallyk2]

Re: Vizio VO47L-FHDTV10A turns on and then off (3 seconds)

Good, the battery is probably low in the bad meter.

LOL. BUDM you are 100% correct. The battery is in fact low in the other meter.