Vizio E470Vl no backlight problem

[chandonh]

can see image with flashlight but can get backlight to come on.

Here are the measurements i get from board #3647-0292-0150 (3J)

Dim 1.40
Lamp 0
On/Off .09
PS On 2.21
12v 12.20
12v 12.20
12v 12.20
SGND 0
SGND 0
SGND 0
SGND 0
+5VSB 5.09
+5VSB 5.09
+5VSB 5.09

any help is much appeciated,thanks

[budm]

Re: Vizio E470Vl no backlight problem

You need to upload good clear pictures of the whole backside of the TV so we can see all the boards, right now you do not have BL-ON (ON/OFF) signal from the main board to turn on the backlight circuits.

'On/Off .09'

[chandonh]

Re: Vizio E470Vl no backlight problem

ok here it goes

[budm]

Re: Vizio E470Vl no backlight problem

I need to see the whole backside so I can see how all the boards are connected together.

[chandonh]

Re: Vizio E470Vl no backlight problem

here they are,sorry about that

[chandonh]

Re: Vizio E470Vl no backlight problem

were these good enough pics,thanks

[budm]

Re: Vizio E470Vl no backlight problem

OK, there are 3 white fuses with Gold ends on the main board close to the white connector with wires that go to the power supply board, check and see what DCV do you have at both ends of those fuses with reference to the chassis GND when the TV is turned on.

[chandonh]

Re: Vizio E470Vl no backlight problem

ok checked them the one at position F1 is 5.05 on both ends of the fuse.the other two fuses measure 12.20 on both ends of both fuses.thanks

[chandonh]

Re: Vizio E470Vl no backlight problem

ok i tested the voltage regulators that were all numbered the same the had the same digits at the top which started out with like a backwards C and the number at the bottom were all 1117 so i assume they should all be the same voltages but i have 1 that is putting out voltage that isn't close to the others.All were taken with tv plugged in and turned on
Here's what they were

U2 1117
P1-2.04
P2-3.27
P3-5.03

U4 1117
P1-0.00
P2-1.25
P3-3.25

U7 1117
P1-2.04
P2-3.28
P3-4.99

U46 1117
P1-2.05
P2-3.30
P3-4.99

THEN I HAVE THESE TOO

U3 G1084
P1-2.01
P2-3.25
P3-4.98

U8 7805CT-RAT021G
P1-12.19
P2-0
P3-4.99

TU5 M113-G1084
ADJ-0.00
0-0.00
I-0.00

[chandonh]

Re: Vizio E470Vl no backlight problem

any help would really be appreciated-thanks

[chandonh]

Re: Vizio E470Vl no backlight problem

bump please

[chandonh]

Re: Vizio E470Vl no backlight problem

any help

[chandonh]

Re: Vizio E470Vl no backlight problem

Desperate for help

[ecking767]

Re: Vizio E470Vl no backlight problem

you need to trace out the back-light signal path using a multi-meter in the continuity function. I had this problem before and I remember some caps and resistors make up the circuit and then to the main processor.

if those caps and resistor are good then its the processor failing to send the voltage to turn on the lamps

you will need magnifying glass 10x or better

[chandonh]

Re: Vizio E470Vl no backlight problem

well i was hoping someone would give me an idea what to check without spending hours looking at traces.i have voltage throughout the board but it just isn't enough to kick on the backlights

[budm]

Re: Vizio E470Vl no backlight problem

well i was hoping someone would give me an idea what to check without spending hours looking at traces.i have voltage throughout the board but it just isn't enough to kick on the backlights

Unless you have the diagram of the main board, then yes, it is VERY time consuming.

[chandonh]

Re: Vizio E470Vl no backlight problem

I signed up for this forum for help not to be told to find the problem and fix it yourself.

[chandonh]

Re: Vizio E470Vl no backlight problem

does anyone know where to buy the 1117 voltage regulators for this tv,thanks

[budm]

Re: Vizio E470Vl no backlight problem

I signed up for this forum for help not to be told to find the problem and fix it yourself.

WTF! Really? Lest see now I do not have the exact same board in front of me to trace, that is right, I have done many tracing and reverse engineering many time before for lots of people here for FREE by spending many hours of my own times!
So good luck with your repair if you do not want to do some work.

[chrismurphy]

Re: Vizio E470Vl no backlight problem

https://cdn.badcaps-static.com/pdfs/...2234c11cc4.pdf