Aquos LC-C5255U

[Techboxcomputer]

Hi All -

I need a opinion. I have this Sharp TV that will not power up and has the 5 and 2 blinking light. I believe I have it narrowed down to the power board or the T Con but I want to be absolutely sure. The T Con is much cheaper. I have nothing but a black screen, no image with a flashlight at all. If I press the volume up and channel down while plugging in I can light all the backlights and they will stay on until I unplug it and power it back up then it goes back up again black with the blink codes. I have read this is a 12v panel error. I am trying to measure the voltage from the 4 wire cable feeding the Tcon from the power board, I am getting no measurement but I may be doing it wrong. Logically, this should be a power board failure as this happened after a wind surge. There is a 40.00 difference between the 2 boards so I am trying to be exactly correct.

Thanks as always.

[dskall]

Re: Aquos LC-C5255U

You will need to force power board on and check voltages

[budwich]

Re: Aquos LC-C5255U

or... disconnect one of the tcon to panel cables and power up and see if you get something happening... then try the same thing with the other cable.

[Techboxcomputer]

Re: Aquos LC-C5255U

You will need to force power board on and check voltages

I assume in order to do this I will need to redo what I posted above? (vol up channel down)

[dskall]

Re: Aquos LC-C5255U

Remove connector from main board to power board. Jump from ps-on pin to standby voltage pin

[budm]

Re: Aquos LC-C5255U

How about the pictures of the power supply board and the Voltage readings of the connectors?
I.E. PNL-POWER command signal and PNL12V output to the T-CON with and without T-CON connector connected/not connected.
There are more than one versions.
http://www.shopjimmy.com/sharp/lc-c5255u

[Techboxcomputer]

Re: Aquos LC-C5255U

How about the pictures of the power supply board and the Voltage readings of the connectors?
I.E. PNL-POWER command signal and PNL12V output to the T-CON with and without T-CON connector connected/not connected.
There are more than one versions.
http://www.shopjimmy.com/sharp/lc-c5255u

OK I will get you more, but here is what I have so far
I forced the power to the board with the volume up channel down I believe and measured the connection from the power board to the tcon board. All I got was a .40 from the top pin of the 4 pin connection.
Thanks, I will attach more pictures soon

[Andrew F. Ali]

Re: Aquos LC-C5255U

On the T-CON Bd look for a tiny fuse near the connector that comes from The Main Bd. You should see 12Vdc on both sides of the fuse wrt chassis GND and you could do a continuity test on the fuse with the TV unplugged from the wall ac outlet.

[Techboxcomputer]

Re: Aquos LC-C5255U

OK, will do. Here are pictures of power, tcon, and mainboard

*update - I do not see this fuse on the TCON anywhere.

[Andrew F. Ali]

Re: Aquos LC-C5255U

How about the pictures of the power supply board and the Voltage readings of the connectors?
I.E. PNL-POWER command signal and PNL12V output to the T-CON with and without T-CON connector connected/not connected.
There are more than one versions.
http://www.shopjimmy.com/sharp/lc-c5255u

I'm not sure but I believe the PNL12V output to the T-CON is that voltage.

[budm]

Re: Aquos LC-C5255U

Yes it is, he should be able to see 12V on that PNL12V pin.

[budm]

Re: Aquos LC-C5255U

What we need from you right now is to have everything connected back up then turn on the TV and see if you do have >2VDC at the PNL-PWR pin and 12V at PNL12V or not.
No PNL-PWR command = no 12V at PNL 12V period, that is what I ask you to do at post #6, just follow the instruction.

[Techboxcomputer]

Re: Aquos LC-C5255U

OK - if I am doing this correctly I am getting no voltage. I grounded my one lead on the metal of the tv (tried a board mount screw also) and pushed the other down through each of the wires one at a time on the lower jack I have pictured below. I believe the set is on I am getting the blinking pattern i stated earlier. I also tried to get a read by touching the contacts on the bottom of the jack where it mounts to the board with no result either. Let me know if I am making a mistake. TIA

[Techboxcomputer]

Re: Aquos LC-C5255U

The picture that was supposed to be attached...

[Techboxcomputer]

Re: Aquos LC-C5255U

In addition to what I posted above, we did this. We forced the TV into bypass mode which lights the backlights. Here are our pin results;
Pin 1 12.8
Pin 2 12.9
Pin 3 12.8
Pin 4 0
Pin 5 0
Pin 6 0
Pin 7 0
Pin 8 2.9
Pin 9 2.9
Pin 10 0
Pin 11 0
Pin 12 0

The backlights will stay up until TV is unplugged and re powered

TIA

[budwich]

Re: Aquos LC-C5255U

I do believe you need to be a little more "precise" in your reading procedure. You need to monitor the test point (12v pin) for power all the time from attempting to power up because if the set is "errored", then powering is removed fairly quickly.

IF you never see the 12v on the pin, then as suggested by budm, you need to then monitor the pnl-pwr to see if it gets any voltage (something more than 2v).

Further, the "blink pattern" is TOO LATE... by that time, the system has determine an issue and has removed powering from various areas.


Passing ships on the internet.... :-) your new post indicates 12v is there.... maybe not... what are pin 1 ,2,3 on that connector... your picture is cut off.
PNL-POW is 0 still.

[budm]

Re: Aquos LC-C5255U

What we need from you right now is to have everything connected back up then turn on the TV and see if you do have >2VDC at the PNL-PWR pin and 12V at PNL12V or not.
No PNL-PWR command = no 12V at PNL 12V period, that is what I ask you to do at post #6, just follow the instruction.

I gave up.
BTW: Always put down the pin name so we can easily know what each pin function are.
Those 12VDC Voltages are not the PNL12V, PNL12V is on the other connector.

[Techboxcomputer]

Re: Aquos LC-C5255U

Bud, I printed your instructions and tried to follow them to the letter yesterday which is why I measured every pin and included a picture. I am sorry if I am not understanding or doing something correctly. I now see in your smaller font it appears I am measuring the wrong connector, I will try again.

[Techboxcomputer]

Re: Aquos LC-C5255U

OK, I tried again this morning I hope I got it right. I plugged in the TV, measure the PL pin and get .3 v until it clicks and dives to zero. Same thing happens with same procedure on PNL 12v .3v to zero after click.(relay or just tv switching off?)
Be patient with me if I am once again incorrect. I can repair any computer you put in front of me and have done it for 20 years, but the TV thing is new to me and I would like to learn it. Thanks for the continued help.

[Techboxcomputer]

Re: Aquos LC-C5255U

This is a edit for the last post by me

"OK, I tried again this morning I hope I got it right. I plugged in the TV, measure the PL pin and get .3 v until it clicks and dives to zero. Same thing happens with same procedure on PNL 12v .3v to zero after click.(relay or just tv switching off?)
Be patient with me if I am once again incorrect. I can repair any computer you put in front of me and have done it for 20 years, but the TV thing is new to me and I would like to learn it. Thanks for the continued help."

Since that last post I now realize the PNL 12v is on the lower jack and gave you that measurement of .3v to zero before it died,(2nd pin named PNL 12v) and the PNL power is on the upper jack and it measures a 2.9v (8th pin named PD1-12 PNL_PWR ) I hope this helps