39L22U Toshiba LED TV

[budm]

Re: 39L22U Toshiba LED TV

You need 1K between 5V and the DIM PIN also, you are going to do force on of the power supply board without having the main board connected.
So what happen to this suggestion" ACD = AC Detect, the signal is used to tell the main board the condition of the incoming AC feeding the TV.
"DIM 0v" 0v = no backlights. So have everything hook back up but not the DIM wire connected to see if the backlights will stay on. 0V on the DIM pin is not normal."

[Gonnafix]

Re: 39L22U Toshiba LED TV

Any thoughts on what could be preventing voltage to the DIM port? Nothing on it looks bad.. I guess I'll trace the circuit and begin testing individual components.

[Gonnafix]

Re: 39L22U Toshiba LED TV

Will retest now.... Thx!

[Gonnafix]

Re: 39L22U Toshiba LED TV

I don't want to waste your time so I'll say here I am a bit confused.

You're asking for:

1K between 5V and the DIM and 1K between PWON to 5V for forced power on?

ACD is 5V

Do I connect BLON to 5v as well?

I completely appreciate your time here, my apologies if I'm not catching on w this.


Thank you!

[budm]

Re: 39L22U Toshiba LED TV

DIM to 5v and PWON to 5 v connected.

You miss one, the BL-ON.

[Gonnafix]

Re: 39L22U Toshiba LED TV

Connected BLON, backlight stays on now.. 11.9v on 12v ports. So it looks like it's switching on..

[budm]

Re: 39L22U Toshiba LED TV

So I like suggest, hook up all the connector back together except the DIM wire, leave that wire off the connector but still have it connected to 5V through the resistor and see what happen.
You are missing the DIM command signal.

[Gonnafix]

Re: 39L22U Toshiba LED TV

Nothing happens.. I'll try and trace that circuit. Thanks!

[budm]

Re: 39L22U Toshiba LED TV

Nothing happens.. I'll try and trace that circuit. Thanks!

No, that does not make any sense because per you reading when you have everything hook up before you have the correct Voltages and signal, the only thing missing is the DIM signal. You MUST disconnect the DIM wire going back to the main board for you to be able to use the resistor between DIM pin on the power supply board and the 5V pin, otherwise the main board will not allow the DIM pin to go high.
We already proof that when you have all the signals the backlights and the power supply do function.
"Connected BLON, backlight stays on now.. 11.9v on 12v ports. So it looks like it's switching on.."

[Gonnafix]

Re: 39L22U Toshiba LED TV

I just pulled the DIM cable from the socket going to main board and jumped w 1k ohm resistor back to PSU 5v connection. Still nothing. Do the other two 1k's have to be connected as well?

[budm]

Re: 39L22U Toshiba LED TV

I just pulled the DIM cable from the socket going to main board and jumped w 1k ohm resistor back to PSU 5v connection. Still nothing.

OK, so you still have all these Voltages?
That your report in the other post

BLON 5v
DIM 0v, You should have about 5VDC at this pin with the resistor in place and the wire is not connected to the main board.
ACD 5v
PWON 4.9v
5vcc 5v
12cc 11.9v
12Va 11.9v

"Do the other two 1k's have to be connected as well?" No ,because the main board should supply all those signals that you have as shown above.
All we are doing is to force the DIM pin high with the resistor, the other controls pins Voltages are supplied by the main board.

[Gonnafix]

Re: 39L22U Toshiba LED TV

BLON 0
DiM 5
ACD 3.5
PWON 0
5V 5V
12Vcc 0
12Va 0

[Gonnafix]

Re: 39L22U Toshiba LED TV

BLON 0
DiM 5
ACD 3.5
PWON 0
5V 5V
12Vcc 0
12Va 0

[budm]

Re: 39L22U Toshiba LED TV

BLON 0 -= BAD
DiM 5
ACD 3.5
PWON 0 = BAD
5V 5V
12Vcc 0 = BAD
12Va 0= BAD

Are these the reading you are getting with all the board and the connectors back in place,? if it is AND THE POWER SWITCH IS ACTIVATED, then something went out on your main board.

[Gonnafix]

Re: 39L22U Toshiba LED TV

I agree with you 100%. Crossing the PSU w 1k jumpers enables it to function properly. So my guess it may be a component on the main board.

[budm]

Re: 39L22U Toshiba LED TV

You better recheck all the connections again.

[Gonnafix]

Re: 39L22U Toshiba LED TV

I've looked everywhere for a schematic to no avail.. This will be my last toshiba TV. Thank you for your time!! Have a great night. By no means am I finished working on this TV

[wldock]

Re: 39L22U Toshiba LED TV

I justed picked up the same set with the same issue. The previous owner said there was a major lightning strike/ power surge. It took out the TV and his Roku. Same symptoms, the power LED turns on and no picture. After checking over the unit, it looks like I don't have 12 Va on the P802 connector but all other voltages look good. The fuse is good but there seems to be several bad diodes top and bottom. Through-hole D201, ZD501, D501, D903 and SMT D105, D104, D906, Q906.

I will give it a go to see if I can repair the board.