Toshiba 55ZV650U No power

[fatkid66]

I went to turn it on one day and nothing. I opened it up, and using advice from tampatec found no standby power at all, which explains no leds lit or anything on the tv. Standby should be 5 vdc, fluke reads 0. The 120vac is there on the board, and the 2 replacable glass fuses are ok, there are 3 fusable resistors on the board, one of which was bad. I have replaced that, but still no standby power, also the voltages on the bridge rectifier are not right either. If this is a power board problem, I would be fine in replacing the whole thing. Any advice?

[CapLeaker]

Re: Toshiba 55ZV650U No power

Right now you have a PSU problem. If you don't get any stby voltage on the PSU, nothing is going to work. also try to disconnect the main board and check the stby voltage again. I guess we need high res pictures of the front and back of the PSU if you want to repair it.

[fatkid66]

Re: Toshiba 55ZV650U No power

I'm a bit of a noob to this, and as they say, a little knowledge can be dangerous! I am not sure where the psu is located, should it be obvious? Is it a board or a component? Also, is the main board the one the power cord directly attaches to or is it the one with all the vid/aud inputs?

[CapLeaker]

Re: Toshiba 55ZV650U No power

PSU = Power Supply

[fatkid66]

Re: Toshiba 55ZV650U No power

Yes i understand that. I suppose you are referring to the entire board that the power cord attaches to. I will try to get some good pics of it tonite if possible, thanks for the assistance.

[nicholas1110]

Re: Toshiba 55ZV650U No power

It is very common for one of the fuseable resistors to open on these boards. You must also either clean or replace the relay that is on the same circuit as the resistor. Search the board number on the forum and you will find a few posts about this board in the 46" version of this tv.

[budm]

Re: Toshiba 55ZV650U No power

Borads:
http://www.shopjimmy.com/catalogsear...shiba+55ZV650U

[CapLeaker]

Re: Toshiba 55ZV650U No power

did you check F840? what resistor did you replace?

[fatkid66]

Re: Toshiba 55ZV650U No power

ok, long story, but I replaced the fused resistor R850, and have my 5v standby power. When I plug it in, relay SR80 changes state, but I get no leds on the tv. power button does nothing. After unplugging, relay SR80 again changes state after a short time delay. Power at bridge rectifier is 122vac and 166.8 vdc. None of the caps on the board are leaking or bulged, and there is little to no heat damage on the board. Any ideas?

[CapLeaker]

Re: Toshiba 55ZV650U No power

maybe the main board is bad too. Who knows until you check PSon with the mainboard connected. You also can disconnect the mainboard, leave the backlights plugged in and force on the PSU and the backlight. Then check all the voltage rails. After that you know if you still have a PSU problem or a mainboard problem.

[fatkid66]

Re: Toshiba 55ZV650U No power

Noob question : the main board is the one with the vid/aud inputs right? Cleaned relay sr80, still same. With power on n all boards connected i still have no leds, only sr80 changing state. I will unplug the main board, how exactly do I force the psu on with the power button out of circuit.

[CapLeaker]

Re: Toshiba 55ZV650U No power

I don't know without any high resolution pictures that show the pin out of the connectors on the power supply or a schematic. Unfortunately the SJ picture does not show the pin out.
The main board is the one with the audio / video inputs.

[budm]

Re: Toshiba 55ZV650U No power

Is this your board?
http://assets.shopjimmy.com/media/ca...4752-top_2.jpg
The POW_TV is the PS-ON pin.

[CapLeaker]

Re: Toshiba 55ZV650U No power

ooops. I looked at a PSU pic for a different TV, thanks budm.

[fatkid66]

Re: Toshiba 55ZV650U No power

That is my board exactly. Which pins do i need to jump out? I only have the 5vdc, no 12v, no 18v

[CapLeaker]

Re: Toshiba 55ZV650U No power

Take a 1k resistor and jump 5v1 STBY to pow-TV. That should get the other power rails going. No main board connected.

[fatkid66]

Re: Toshiba 55ZV650U No power

K, ill give that a try tomorrow, thanks.

[fatkid66]

Re: Toshiba 55ZV650U No power

Does the wattage of the resistor matter?

[budm]

Re: Toshiba 55ZV650U No power

1/4 W will be just fine, no need for high Wattage..

[fatkid66]

Re: Toshiba 55ZV650U No power

K thanx im trying to keep 5 balls in the air at once, its taking me time to get back to this...