Vizio VF550XVT1A Constant Black Screen.

[budm]

Re: Vizio VF550XVT1A Constant Black Screen.

I want you to check the Voltage between the chassis GND and each end of that fuse.

[budm]

Re: Vizio VF550XVT1A Constant Black Screen.

I think it is time for you to buy the working MASTER and the SLAVE inverter boards.

[seananamous]

Re: Vizio VF550XVT1A Constant Black Screen.

I think it is time for you to buy the working MASTER and the SLAVE inverter boards.

Ok I checked both ends of the fuse with the ground. I got 0.4 for both chips.

Should I still purchase the inverter boards?

I found a set for $60 - http://www.ebay.com/itm/LG-55LH40-UA...gAAOSwepJXWJs9

[budm]

Re: Vizio VF550XVT1A Constant Black Screen.

Ok I checked both ends of the fuse with the ground. I got 0.4 for both chips.

Should I still purchase the inverter boards?

I found a set for $60 - http://www.ebay.com/itm/LG-55LH40-UA...gAAOSwepJXWJs9

What chips? We are talking about fuse here, may be you should look up what fuse is and what it is for.
One end of that F1 fuse is connected directly to those VIN pins so no way you can have 0 Volt at both ends of the fuse, operator error to me, not to have at least 24VDC at one end of the fuse, the big fat trace from VIV pins to one end of the fuse must have blown up big time which I doubt it.
This is post #24 and we still do no get good answer about the DCV reading on the fuse which started at my post 9.
I will let someone else chime in at this point.

[dick_barton]

Re: Vizio VF550XVT1A Constant Black Screen.

With the meter set to DC volts and the black lead connected to chassis use the red lead and measure the voltage on each side of the white fuse in turn as shown in the attachment and report what you find.

[seananamous]

Re: Vizio VF550XVT1A Constant Black Screen.

Well I just noticed the TV turned off as I was testing it the first time.
Now I get a reading of 23.8 for the fuse - master & slave.

When I said both chips the first time I was testing the fuse but referring to the master & slave chip.

[vinceroger69]

Re: Vizio VF550XVT1A Constant Black Screen.

Well I just noticed the TV turned off as I was testing it the first time.
Now I get a reading of 23.8 for the fuse - master & slave.

When I said both chips the first time I was testing the fuse but referring to the master & slave chip.

please confirm that its 23.8 volts too both sides of the fuses

[seananamous]

Re: Vizio VF550XVT1A Constant Black Screen.

please confirm that its 23.8 volts too both sides of the fuses

Yes I checked it again. 23.8 for both sides of the fuse "F1" for the master & slave chip.

[seananamous]

Re: Vizio VF550XVT1A Constant Black Screen.

So if both sides of the fuse are good does that mean the problem is not the inverters?
Thanks

[dick_barton]

Re: Vizio VF550XVT1A Constant Black Screen.

Have 2 out of 3 of those capacitors (680uF,35V) on the inverter board been leaking? It could be flux on the capacitor legs but hard to tell from a picture.

[seananamous]

Re: Vizio VF550XVT1A Constant Black Screen.

Have 2 out of 3 of those capacitors (680uF,35V) on the inverter board been leaking? It could be flux on the capacitor legs but hard to tell from a picture.

I see nothing leaking out of the capacitors. I think it's the flux.

[seananamous]

Re: Vizio VF550XVT1A Constant Black Screen.

Update:
Got the inverters in and exchanged both. Still black screen...
What could be the issue now?

[vinceroger69]

Re: Vizio VF550XVT1A Constant Black Screen.

could a back light itself be at fault ? i guess this is a ccfl type and not a led set

[budm]

Re: Vizio VF550XVT1A Constant Black Screen.

Did you verify that all the signals and the Voltage are present with the new board?
The caps on the new boards look fine, any sign of them being replaced.
Did you even see the backlights flash on for seconds? If you have bad lamp/s the inverter should still try to fire up the lams FIRST then the protection circuit will kick in AFTER.

[sgeorge]

Re: Vizio VF550XVT1A Constant Black Screen.

I have fixed 3 or 4 of your vizio tv every single one of them had a bad main board. had the same symptoms as yours. steve

[vinceroger69]

Re: Vizio VF550XVT1A Constant Black Screen.

in post 12 it says you have swopped the mainboard if this is a common issue i guess you could of got another bad one. Budm do you think this could possibly be a mainboard issue? or are the correct signals/voltages being sent already by the mainboard too the invertor board.

[budm]

Re: Vizio VF550XVT1A Constant Black Screen.

His post 14 shows what he has with his old board, so what is he getting now with the new boards? The dimming signal is on a low side but at least he should see the backlights flash on.

[ecking767]

Re: Vizio VF550XVT1A Constant Black Screen.

I agree with sgeorge, The main board could be the problem, I would measure the voltage regulators on the main board and the +12 fuse in standby mode

if +12v is present then there is a problem somewhere on the main board. and not all of the voltage regulators should be active in standby mode.

[ReeceyBurger123]

Re: Vizio VF550XVT1A Constant Black Screen.

I think your new inverter is still at fault, retest if you have the voltages there.

[madlee357]

Re: Vizio VF550XVT1A Constant Black Screen.

I see images on my set but dark