Proscan PLDED3996A led backlight help

[boxingfan]

hi everyone, i have this Proscan 39 with a backlight that is not working, forgive me if my question is dumb, i can see the menu when i point a flashlight to the screen that's why i think is the backlight. there are four wire(black/red-black/white) going from the power supply to the back of the screen. my question is should i be getting any volts out of these wires? i'm not getting any
any help? thanks

edit:i double checked i have black/white 9v and black/red 59v is that ok?, is there board behind the screen? sorry i'm learnig

[tom66]

Re: Proscan PLDED3996A led backlight help

What do you measure from WHITE/BLACK to RED/BLACK (there appear to be two wires going into the connector, I am guessing they fan out.)

[boxingfan]

Re: Proscan PLDED3996A led backlight help

thank you for reply, i get 9v out of black/white 59v out of red black, how im supposed to measure? i have three pin on the power supply but four wire going out,

[tom66]

Re: Proscan PLDED3996A led backlight help

You have to measure across: red probe on end, black on other. Just measure between the RED/BLACK pin and the WHITE/BLACK pin.

[boxingfan]

Re: Proscan PLDED3996A led backlight help

i have 0.026v with tv on

[tom66]

Re: Proscan PLDED3996A led backlight help

Before, when you reported 9V, and 59V, how were you measuring that? Black probe on chassis?

[boxingfan]

Re: Proscan PLDED3996A led backlight help

Before, when you reported 9V, and 59V, how were you measuring that? Black probe on chassis?

yes black on chassis

[boxingfan]

Re: Proscan PLDED3996A led backlight help

so do you think is volts problem or the light? sorry im new to this

[tom66]

Re: Proscan PLDED3996A led backlight help

Please try across those pins again. Very odd reading. If it is still low, the next step would be isolating the connection to see if the LED strip is possibly shorted.

[boxingfan]

Re: Proscan PLDED3996A led backlight help

Thanks again
First reading tv on, plug out off ps, red on black/red pin black on black/white pin 0.023v
Second reading tv on, plug off ps, black on black/red pin red on black/white pin -0.023v

[boxingfan]

Re: Proscan PLDED3996A led backlight help

edit
0.023v
-0.023v

[tom66]

Re: Proscan PLDED3996A led backlight help

Plug should be in PSU. As if normally installed. If testing directly is difficult/impossible, try inserting a wire or paperclip into each pin of interest.

[boxingfan]

Re: Proscan PLDED3996A led backlight help

with the plug plugged in(the one that goes to the light) and tv on i have almost the same 0.023-0.030 volts

thanks for you help

[boxingfan]

Re: Proscan PLDED3996A led backlight help

Bump, I checked all caps around the backlight connector and all good, I'm really lost here any help will be appreciated, thanks

[boxingfan]

Re: Proscan PLDED3996A led backlight help

What the reading of this resistors should be? i working with this DMM, thanks

[tom66]

Re: Proscan PLDED3996A led backlight help

For the voltage check reading 0.023V, could you take a picture of how you are testing? It's just the readings are counter-intuitive.

[boxingfan]

Re: Proscan PLDED3996A led backlight help

this how i set the DMM when checking for voltages and i got all my reading right when checked the other side of the ps the one to the main board

[tom66]

Re: Proscan PLDED3996A led backlight help

Can you make a picture of how you probe... may require a third hand...

[boxingfan]

Re: Proscan PLDED3996A led backlight help

im here alone my wife be back within 3-4 hours, i took a pic with one hand just so you see where i put the prove, and i know im making contact when i first turn the tv on i get like 0.80v after 2+ mins with tv on i get 0.023v-0.030v
thanks

[boxingfan]

Re: Proscan PLDED3996A led backlight help

one question, one connection on main board says inverter and goes back to the ps is this what send power to the backlight?. reading 1.4 when tv on