Vizio e470va No Picture

[at1105]

Re: Vizio e470va No Picture

OK, the standby power supply is working and the main board is sending out the ps_on a and the bl-on, so now you need to check the dcV on the main filter cap's legs to see if it has >360Vdc on its two legs, you need that for the power supply to produce 12V for the main board and 24V for the inverter board.
Do not touch anything with your hands or body.

Both large caps on the middle of the power board are reading 389v.

[budm]

Re: Vizio e470va No Picture

Good, so check and see if you do have 24V feeding the inverter board and 12V feeeding the main board, if not, remove the cables to the inverter board and check again to see if the 12V/24V are present.

[at1105]

Re: Vizio e470va No Picture

Good, so check and see if you do have 24V feeding the inverter board and 12V feeeding the main board, if not, remove the cables to the inverter board and check again to see if the 12V/24V are present.

23.9v at the connector on the inverter board and 12.10v/23.9v at the connector on the main board.

[budm]

Re: Vizio e470va No Picture

OK, now we need good clear pictures of the inverter board without the metal shield, you need to check the fuses on the inverter board.

[newtothis]

Re: Vizio e470va No Picture

Original post says the backlights initially display but no image, voltage at lower end of LVDS cable yet no power at tcon fuse either side, Is the cable passing signal ok?

[at1105]

Re: Vizio e470va No Picture

ok, now we need good clear pictures of the inverter board without the metal shield, you need to check the fuses on the inverter board.

[newtothis]

Re: Vizio e470va No Picture

F1

[CapLeaker]

Re: Vizio e470va No Picture

How did we go from a main board LCD problem to a backlight problem? I thought the backlight is working fine?

[at1105]

Re: Vizio e470va No Picture

OK, now we need good clear pictures of the inverter board without the metal shield, you need to check the fuses on the inverter board.

no voltage on the fuse

[nomoresonys]

Re: Vizio e470va No Picture

wonder if the mainboard is sending proper signal to tcon?

[nomoresonys]

Re: Vizio e470va No Picture

could be bad cap on inverter maybe?

[at1105]

Re: Vizio e470va No Picture

How did we go from a main board LCD problem to a backlight problem? I thought the backlight is working fine?

Yes. Backlight works perfect. Just not getting a display.

[CapLeaker]

Re: Vizio e470va No Picture

You got to figure out why the main board isn't properly turning on. I bet, if you would check the LVDS cable with an oscilloscope right now, there wouldn't be any signal either.

[newtothis]

Re: Vizio e470va No Picture

You got to figure out why the main board isn't properly turning on. I bet, if you would check the LVDS cable with an oscilloscope right now, there wouldn't be any signal either.

This is what I am thinking

[newtothis]

Re: Vizio e470va No Picture

no voltage on the fuse

Are you using your meter correctly as when the backlights are on you WILL have voltage at that fuse

[budm]

Re: Vizio e470va No Picture

How did we go from a main board LCD problem to a backlight problem? I thought the backlight is working fine?

That what I thought in the first in post 1 but some how I thought we lost the 24V and the 12V which nay be why one of the regulator on the main board shows <0.050V).
Now we do not know if the meter is good or if it is being used correctly.
The 24V should be at the fuse if he does have backlights, this is really frustrating and confusing when we do not get correct readings.

[CapLeaker]

Re: Vizio e470va No Picture

this is really frustrating and confusing when we do not get correct readings.

amen!

[at1105]

Re: Vizio e470va No Picture

That what I thought in the first in post 1 but some how I thought we lost the 24V and the 12V which nay be why one of the regulator on the main board shows <0.050V).
Now we do not know if the meter is good or if it is being used correctly.
The 24V should be at the fuse if he does have backlights, this is really frustrating and confusing when we do not get correct readings.

Apparently my meter skills are lacking severly in this dept. I was checking it with the positive lead on one side and the neg on the other. I'm assuming that was incorrect as I put the negative lead on the ground wire coming in on the inverter board and the positive at the fuse and got 24v on both sides. is that correct?

[at1105]

Re: Vizio e470va No Picture

Are you using your meter correctly as when the backlights are on you WILL have voltage at that fuse

Apparently my meter skills are lacking severly in this dept. I was checking it with the positive lead on one side and the neg on the other. I'm assuming that was incorrect as I put the negative lead on the ground wire coming in on the inverter board and the positive at the fuse and got 24v on both sides. is that correct?

[CapLeaker]

Re: Vizio e470va No Picture

which fuse on what board? Just trying to keep things straight. To test the fuse, put the negative lead to chassis ground and the positive lead on each side of the fuse. DMM in DC setting.