Westinghouse wg55ur4100 no response

[microvibe]

I have a Westinghouse TV, when I plug it in the green light comes on no backlight no video showing on the screen with flashlight listed below are the voltages.

There is no response when pressing buttons on tv or remote.

Cn201
V12= 12.3v
V12= 12.3v
Gnd
Gnd
Gnd
V5= 5.1v
V5= 5.1v
Stb= 5.1v
Ps-on= 3.1v
V5= 5.1v
V5= 5.1v

Cn202
V24= 24.6v
V24= 24.6v
Gnd
Gnd

Led2+ 0v
Led1+ 0v

Led2- 0v
Led1- 0v

Cn206

Bk= 0.1v
Adj= 0v
Gnd
Gnd

[nomoresonys]

Re: Westinghouse wg55ur4100 no response

With tv unplugged from power, unhook cable from powerboard to mainboard, plug tv into power, see if backlight comes on and stays on.

[budm]

Re: Westinghouse wg55ur4100 no response

Bk= 0.1v. Bad, there is no BL-ON from main board to turn on backlights circuit.
Adj= 0v. Bad, there is no Dimming control control signal from main board.

[microvibe]

Re: Westinghouse wg55ur4100 no response

So find new main board. Or possible trouble shoot bl on circuit?

[budm]

Re: Westinghouse wg55ur4100 no response

Try heating with hair dryer and cooling (use canned airduster upside down) the main board to see what will happen.

[microvibe]

Re: Westinghouse wg55ur4100 no response

Tried heating and cooling no change.

[CapLeaker]

Re: Westinghouse wg55ur4100 no response

Looks like the TV is actually running, just no backlights...

BLon is generated on the main IC on the main board. :-(
You could try to unhook the BLon at the PSU, and jump STBY or PSon to it via a 1k or so resistor. Just make sure you don't backfeed power. I'd either cut the BLon wire or take the wire with the pin out of the connector.

[nomoresonys]

Re: Westinghouse wg55ur4100 no response

Test results from post #2??

[microvibe]

Re: Westinghouse wg55ur4100 no response

No backlights doing what says in post 2

[microvibe]

Re: Westinghouse wg55ur4100 no response

Jumped bl on still no backlights. The led connector showing 3.5v on led1+ thats it. I cant find a 12v supply on tcon ethier

[nomoresonys]

Re: Westinghouse wg55ur4100 no response

Probably need to use a resistor on each pin ps-on and BK and maybe ADJ too, going to 5v standby, so 3 resistors, one going from each of those pins to 5v stndby. That might bring backlights on to verify backlights and powerboard.

[nomoresonys]

Re: Westinghouse wg55ur4100 no response

But most of the time when those voltages are low or missing it's just a faulty mainboard as mentioned.

[budm]

Re: Westinghouse wg55ur4100 no response

Jumped bl on still no backlights. The led connector showing 3.5v on led1+ thats it. I cant find a 12v supply on tcon ethier

Did you disconnect the BL-ON wire before jumping it? I hope you did otherwise you will damage the main board, which at this point it already has problems.

[nomoresonys]

Re: Westinghouse wg55ur4100 no response

Probably need to use a resistor on each pin ps-on and BK and maybe ADJ too, going to 5v standby, so 3 resistors, one going from each of those pins to 5v stndby. That might bring backlights on to verify backlights and powerboard.

Oh shit, forgot to say if you do this MAKE SURE the cable/s from powerboard to mainboard are unhooked.

[microvibe]

Re: Westinghouse wg55ur4100 no response

Ill try jumping all 3 to stby. I did unhook main.

[microvibe]

Re: Westinghouse wg55ur4100 no response

Jumping all 3 to stby worked for backlights. So guess need find main board unless possible to trace where issue on main is.

[nomoresonys]

Re: Westinghouse wg55ur4100 no response

Nice job, yes sure looks like the main is the problem.

[microvibe]

Re: Westinghouse wg55ur4100 no response

Cant seem to find replacement main board, be nice if these main boards could be repaired.

[microvibe]

Re: Westinghouse wg55ur4100 no response

Would main board from50" work or one from 55" element?

[CapLeaker]

Re: Westinghouse wg55ur4100 no response

Well, there are too many main boards. You have to look after an CV838H-B from a 55 inch tv. I could cut it down to 6 different main boards. Anyway, maybe take the main board out and see if there is a sticker on the back of it.