Vizio e470i-a0 - blank screen, goes straight to standby

[jjjacer]

I am trying to repair a Vizio TV for a friend, about half a year ago i replaced its mainboard/tcon board as the PSU was not getting the PWR/BL signal from it. and all voltages looked good (got backlight when manually jumping the PSU)

Well it stopped working again, was told they had sound but no image. I got it and i cant even get the device to get sound. the power LED comes on and fades away. I have 3.3v~ on both the PWR and the BL pins, 5.1v on the 5v rails and 11.9v on the 12v rails. However at the time i had no voltage to the LED's

Replaced the power supply, same results. same voltages except at least now im getting power to the LED's, LED1 is getting 99v and LED2 is getting 130-136v.

Its sounding like bad LED's but I cant see any image with a flashlight although that could be me being bad at seeing things.

Any Ideas? Im hoping its not the LED's as its going to make this TV not worth the extra repairs and I just replaced that motherboard not to long ago however it is out of the initial 90day warranty.

[realdealthill]

Re: Vizio e470i-a0 - blank screen, goes straight to standby

I have repaired about 6 of the same model tv within the 2 weeks, with the exact same problem. They all had bad leds..Very cheap fix , but time consuming

[realdealthill]

Re: Vizio e470i-a0 - blank screen, goes straight to standby

Tear tv down to led stips

Solder 2 AA batteries together, Neg to Pos

Solder leads to other sides, and solder the thickest sewing needles you can find at the ends

Test each led by, pericing the Pos lead to the right pad and neg to left pad. Appy good pressure and a couple of wiggles to make connect under plastic

[budm]

Re: Vizio e470i-a0 - blank screen, goes straight to standby

Be careful using batteries testing LED without current limiter due to if the applied Voltage is applied with wrong polarity to the LED, the protection diode in the LED will heavily conduct if the polarity is not observed and it will shorted out and you will damage good LED. So make sure you have verify the correct polarity of the LED first.

[Andrew F. Ali]

Re: Vizio e470i-a0 - blank screen, goes straight to standby

Be careful using batteries testing LED without current limiter due to if the applied Voltage is applied with wrong polarity to the LED, the protection diode in the LED will heavily conduct if the polarity is not observed and it will shorted out and you will damage good LED. So make sure you have verify the correct polarity of the LED first.

Yes I think LEDs bad also....I used an analogue meter on RX1 to test LEDs like that...........I bought the LED Tester and use that instead, now.