Vizio e470vl logo turns white but no picture

[ruben6805]

ive been reading post and searching for solutions for my problem.
so the amber stand by light is on. when i power on the vizio light goes from amber to white. But the back light does not come on. i tested the power outputs at cn201

Power off

DIM __0__Volts
LAMP__0__Volts
On/Off__0.05__Volts
PS_ON__0.08__Volts
12V__0__Volts
12V__0__Volts
12V__0__Volts
GND
GND
GND
GND
+5V__5.15__Volts
+5V___5.15__Volts
+5V__5.15___Volts

Power on
DIM __2.80__Volts
LAMP__0__Volts
On/Off__0.50__Volts
PS_ON__2.22__Volts
12V__12.27__Volts
12V__12.27__Volts
12V__12.27__Volts
GND
GND
GND
GND
+5V__5.12__Volts
+5V___5.12__Volts
+5V__5.12___Volts

i received thus tv from a co worker that said it just stopped working one day. looking for direction on what to check for.

[Ltank]

Re: Vizio e470vl logo turns white but no picture

It appears that the Main Board is not sending the Lamp Command to the P.S. If the Lamp
Pin is not shorted to ground (resistance check with power off-road unplugged) The Lamp pin can be jumped with 100 to 500 ohm resistor to the 5 vdc standby pin and powering set up. This will let you know it all works except for that Lamp on command. Then you can take a closer look at that problem.

[ruben6805]

Re: Vizio e470vl logo turns white but no picture

as i left the set plugged up and powered on the screen did flicker on for about 5 secs and back off. i checked tosee if it was shorted to ground by unplugging and ohming out. got 58 ohms. so i read another post that i can get the jumpers from radio shack.

[budm]

Re: Vizio e470vl logo turns white but no picture

"On/Off__0.50__Volts " That is the BL_ON pin that needs to be jumped to 5VSTBY with resistor.

"LAMP__0__Volts" I believe this is the feedback signal from the inverter back to the main board to tell if the lamps light up or not.
Can we see the pictures of the back side of the TV to see how all the boards are connected?

[ruben6805]

Re: Vizio e470vl logo turns white but no picture

trying to upload photos as an attachment but getting an error

[ruben6805]

Re: Vizio e470vl logo turns white but no picture

[ruben6805]

Re: Vizio e470vl logo turns white but no picture

"On/Off__0.50__Volts " That is the BL_ON pin that needs to be jumped to 5VSTBY with resistor.

"LAMP__0__Volts" I believe this is the feedback signal from the inverter back to the main board to tell if the lamps light up or not.
Can we see the pictures of the back side of the TV to see how all the boards are connected?

I used a resistor to jump the "On/Off__0.50__Volts" from the 5VSTBY and it worked.

[budm]

Re: Vizio e470vl logo turns white but no picture

So you get the backlights to stay on?
At this point you need to troubleshoot the main boards, I see two fuses, and voltage regulator ICs which need to be tested and report the voltage readings of each regulators.

[ruben6805]

Re: Vizio e470vl logo turns white but no picture

yes when i powered the tv on with the jumper it stays on

so thats on the main board and not the PS board? correct?

[budm]

Re: Vizio e470vl logo turns white but no picture

I edited my post #8.

[ruben6805]

Re: Vizio e470vl logo turns white but no picture

7805CT
RAB004
pin1- 12.13
pin2- 0
pin3- 487

M131
G1084
pin1- 2.03
pin2-3.28
pin3-4.99

M165
G1084
pin1- 0.59
pin2- 1.83
pin3- 3.28

EH11A
012N28
pin1- 2.05
pin2- 3.30
pin3- 5.05

EH11A
012N28
pin1- 2.06
pin2- 3.31
pin3- 5.01

EH11A
012N28
pin1- 0
pin2- 1.25
pin3- 3.28

EH11A
012N28
pin1- 2.05
pin2- 3.30
pin3- 5.01

this is what i got testing 7 voltage regulators.

[budm]

Re: Vizio e470vl logo turns white but no picture

They all look good except the 7805 which should have 5V output.
7805CT
RAB004
pin1- 12.13
pin2- 0
pin3- 487

Recheck that 487??? again.

[ruben6805]

Re: Vizio e470vl logo turns white but no picture

rechecked

7805CT
RAB004
pin1- 12.23
pin2- 0
pin3- 5.02

[budm]

Re: Vizio e470vl logo turns white but no picture

That is good, so that is about it that I can suggest, you can look real close at the board to see if you can see any burnt or broken parts, otherwise get the new board.

[ruben6805]

Re: Vizio e470vl logo turns white but no picture

so a new main board should fix it? not the power supply board correct?

[budm]

Re: Vizio e470vl logo turns white but no picture

Yes, since you are getting the 5VSTBY, 12V, and can force backlights on using resistor.
BTW, when you force on the backlights, did you still have the cable connected between the main board and the power supply? if you have it connected, did you see pictures on the screen?

[ruben6805]

Re: Vizio e470vl logo turns white but no picture

ok cool ill try to find one and report back here when i do. thanks budm!!!!

[ruben6805]

Re: Vizio e470vl logo turns white but no picture

yes when i forced the backlights on cable was connected and picture and sound came on.

[budm]

Re: Vizio e470vl logo turns white but no picture

OK, if you want to save money, you can wire up a switch to apply the 5VSTBY through the resistor to the BL_ON pin (you should cut that wire so the main board will not load down that BL_ON line), or build circuits to supply the signal.

[ruben6805]

Re: Vizio e470vl logo turns white but no picture

so if i leave the resistor in there and that should be fine? what line should i cut?