Vizio E470i-A0 - FL test ok, half bl working

[anthonystv]

Re: Vizio E470i-A0 - FL test ok, half bl working

I just put the front escution back on its working and I have done NOTHING to fxi it

[budm]

Re: Vizio E470i-A0 - FL test ok, half bl working

Your TV has dynamic contrast control (Faked Dynamic contrast spec), the backlights level will vary with the Video signal.
But the amount of variation you are seeing is not big at all, 0.380 ~ 0.404V it is less than 10%.
Look to see if you can turn off the Dynamic contrast function in t he OSD user settings menu

[anthonystv]

Re: Vizio E470i-A0 - FL test ok, half bl working

Is there any way the Main Board could Instruct the one channel to shut down even if its a malfunction on that control line ?

[budm]

Re: Vizio E470i-A0 - FL test ok, half bl working

No, typical backlights protection circuit in the LED driver will shut down All output if one or both loads are not present, it will also shut down if one or both detect over current.
Some TV will send the error signal to the main board when the protection circuit kicks in so main board will set the error code.

[budm]

Re: Vizio E470i-A0 - FL test ok, half bl working

BTW, in your video where you show the test points using the leg of the R9110, R9210.
It shows that low (0.38V ~ 0.44V) because that is the vdrops on the current sensing resistor, the Voltage will be higher if you measure the Voltage at pin 1 and pin 5 of the LED connector.
Can you check the resistance value of R9110 and R9210?

[anthonystv]

Re: Vizio E470i-A0 - FL test ok, half bl working

ill do that monday it is higher on the pin did you watch all the videos I uploaded ?

[anthonystv]

Re: Vizio E470i-A0 - FL test ok, half bl working

So we still have a mystery because only the one channel is affected by the video not the other and I agree with you can't see why it would be designed that way. But you saw it. And the channel that is affected is the channel we were having issues with shutting down .

[budm]

Re: Vizio E470i-A0 - FL test ok, half bl working

1) Your post #32: STEADY VOLTS
So 105v >>>>>>>27 LEDS .7 VDC ,,,,,,,back to power board
thats from the set that works with no issues.
My reply on post #33:
"As you can see it does not add up, and you get the same result with replacement power supply.
But you indicated that you have working TV for comparison so if you transfer the board from non-working to the working TV one at a time then you can see if the boards from the bad set are good or not."
You never reply to let me me know if you have done that or not, that will tell you if the symptom will change or follows the board or not.
2) Your post #47:
So we still have a mystery because only the one channel is affected by the video not the other and I agree with you can't see why it would be designed that way. But you saw it. And the channel that is affected is the channel we were having issues with shutting down .
Answer, that will easy to prove by checking the working set to see if it does the same thing all not.
3) You have two same model TV one is working and one is not working correct with backlights that go out, that should be easy to do comparison test and do the board swapping.

[anthonystv]

Re: Vizio E470i-A0 - FL test ok, half bl working

I have one tv I have 2 sets of power boards ...actually 3 but IM ignoring that one completley as it was the original board in the tv and is actually different but crosses to the boards were working with
The resistor values you asked for a are 1.8 ohm and 1.7 ohm with about .4 ohm error on shorted probe 0 check The tv is running this morning and the volatges are as follows 105 at initial start up then when i get picture drops to 100v both channels

[anthonystv]

Re: Vizio E470i-A0 - FL test ok, half bl working

Im going to button this up the customer is stoning me for his tv ... both boards react the same .. I have the kit from Shopjimmy

[anthonystv]

Re: Vizio E470i-A0 - FL test ok, half bl working

Since its working it came right on this am with no issues it worked all day sat with no issues Im going to call it fixed but this is good information for anyone trying to repair these boards..
Thanks for your help

[anthonystv]

Re: Vizio E470i-A0 - FL test ok, half bl working

The color codes on the resistors make no sense to me since I calculate 15 ohms
but that is obviously wrong

[anthonystv]

Re: Vizio E470i-A0 - FL test ok, half bl working

Spoke too soon acting stupid once again
https://www.youtube.com/watch?v=Ofel9i31FY0

[anthonystv]

Re: Vizio E470i-A0 - FL test ok, half bl working

well its related to hdmi signal somehow
https://www.youtube.com/watch?v=5TIVgQVMQts

[anthonystv]

Re: Vizio E470i-A0 - FL test ok, half bl working

Pin 11. 2.5 v pin 10. .119. Short pin 10 to pin 11 and ch 2 starts up. Plug to the main board

[anthonystv]

Re: Vizio E470i-A0 - FL test ok, half bl working

to my surprise The BL adjustment still works

[anthonystv]

Re: Vizio E470i-A0 - FL test ok, half bl working

conclusion BAD MAIN BOARD

[anthonystv]

Re: Vizio E470i-A0 - FL test ok, half bl working

left the jumper and its going out the door! DONE