Sharp LC-C4655U Flashing OPC and Power lights.

[berrmich]

I have the above TV. Black screen. Power blinks 2 times. OPC blinks once. Plug in with channeldown/volup. Powers up with solid green power but no light. I removed, cleaned and tightened the screwed on the inverters. I tested plug coming from the power supply to the inverter board when unplugged. INV12V shows 7.4 V DC. INV60V shows 0.1 or something like that. After plugging in the cable I don't get meaningful voltage from either one. (I measured after booting the TV with channeldown/volup.)

Is this a bad power supply? Or am I measuring something wrong.

-Mike

[zwarder]

Re: Sharp LC-C4655U Flashing OPC and Power lights.

What psu is in it ?
Usually a RUNTKA***** number
Some good info in this thread
https://www.badcaps.net/forum/showthread.php?t=44622

[nomoresonys]

Re: Sharp LC-C4655U Flashing OPC and Power lights.

Good focused straight on pictures of each board and one of the whole back as to see how everything is connected.

[berrmich]

Re: Sharp LC-C4655U Flashing OPC and Power lights.

Thanks! Here are some pictures.

[nomoresonys]

Re: Sharp LC-C4655U Flashing OPC and Power lights.

Check voltages on PD1, meter set to vdc, neg. probe on metal chassis ground, pos. probe on each of the 12 pins, report results as pin 1 sv signal and the voltage, do that for each pin.

[berrmich]

Re: Sharp LC-C4655U Flashing OPC and Power lights.

1 - 0 (13.7V_Signal)
2 - 0
3 - 0 (13.5V_Audio)
4 - 0
5 - 0 (SGND_Audio)
6 - 0
7 - 0 (SGND)
8 - 3.18V
9 - 0 (AC_DET)
10 - 0 (PS_ON)
11 - 0 (BU5V)
12 - 5V (PNL_POW)

Pin number - Voltage measured (Description)

Just to be clear, only pin 8 and 12 had any voltage.

[nomoresonys]

Re: Sharp LC-C4655U Flashing OPC and Power lights.

Not exactly sure what all pins need to be connected but you can try unhook cable from powerboard to mainboard, I do it on mainboard side, trace the wires out from pin 8 and pin 10 take about a 1k ohm resistor and jump from those two at the cable connector end, so the cable will be unhooked at the mainboard leave that end uhnooked for test, put jumper resistor in and retest those 12 pins voltages and see what you get.

[nomoresonys]

Re: Sharp LC-C4655U Flashing OPC and Power lights.

You don't have any voltage on the AC_DET, I'm thinking there should be voltage there on this one but not sure, someone else may remember, haven't worked with a good old ccfl tv much lately.

[berrmich]

Re: Sharp LC-C4655U Flashing OPC and Power lights.

So I measured those without the plug in. When the plug is in I get:

5v on pin 12
0.7v on pin 9 (AC_Det)
3.0v on pin 8

The rest are 0.
This is when starting the TV with channel down / vol up to bypass the error.

[R_J]

Re: Sharp LC-C4655U Flashing OPC and Power lights.

This is the US model board so the pin numbers for plug PD(US) are different than PD1(EU)
1-13.5 (sig)
2,3-13.5 (aud)
4,5 (aud gnd)
6,7 (sig gnd)
8 (ac_det)
9 (PS_ON)
10 (pnl_pow)
11 (sgnd)
12 (BU5V)
To turn on the power supply board (disconnect cable from main board) connect BU5V to PS_ON This should give 13.5v and INV60v

[berrmich]

Re: Sharp LC-C4655U Flashing OPC and Power lights.

Ok. Now I'm a little confused. PD1 is EU. PD is US. Probably makes a little more sense. PS_ON is still only 0.7V. I'll see if I can get a resistor tomorrow and see if 3V will turn everything on? Could be the main board then?

Also PS_ON is only 0.7v if I start it with channeldown/volup. Otherwise it is 0.

Pin 1 - 0 (13.7V_Signal)
Pin 2 - 0 (13.7V Audio)
Pin 3 - 0
Pin 4 - 0 (SGND_Audio)
Pin 5 - 0
Pin 6 - 0 (SGND)
Pin 7 - 0
Pin 8 - 3V (AC_DET)
Pin 9 - 0.7v (PS_On)
Pin 10 - 0 (PNL_POW)
Pin 11 - 0 (SGND)
Pin 12 - 5V (BU5V)

[R_J]

Re: Sharp LC-C4655U Flashing OPC and Power lights.

If you are carefull and don''t connect B5V to ground, you don't need a resistor, there already is a 10kΩ (R7300) on the board

[nomoresonys]

Re: Sharp LC-C4655U Flashing OPC and Power lights.

The resistor is just for safety so nothing shorts out in case you jumper the wrong pins, not needed if it's jumpered correctly, so looks like you want to jumper 12 and 9, then see if you get those missing voltages.

[nomoresonys]

Re: Sharp LC-C4655U Flashing OPC and Power lights.

Ok. Now I'm a little confused. PD1 is EU. PD is US. Probably makes a little more sense. PS_ON is still only 0.7V. I'll see if I can get a resistor tomorrow and see if 3V will turn everything on? Could be the main board then?

Also PS_ON is only 0.7v if I start it with channeldown/volup. Otherwise it is 0.

Pin 1 - 0 (13.7V_Signal)
Pin 2 - 0 (13.7V Audio)
Pin 3 - 0
Pin 4 - 0 (SGND_Audio)
Pin 5 - 0
Pin 6 - 0 (SGND)
Pin 7 - 0
Pin 8 - 3V (AC_DET)
Pin 9 - 0.7v (PS_On)
Pin 10 - 0 (PNL_POW)
Pin 11 - 0 (SGND)
Pin 12 - 5V (BU5V)

Those voltages are correct, this is what you should see when the tv is plugged in and just in standby, then when you turn it on you would get the rest of the voltages, when you jumper those pins if you get the missing voltages and the correct voltage on ps-on, then you know that part of the powerboard is ok.

[berrmich]

Re: Sharp LC-C4655U Flashing OPC and Power lights.

Pin 1 - 13.2V (13.7V_Signal)
Pin 2 - 13.2V (13.7V Audio)
Pin 3 - 13.2V
Pin 4 - 0 (SGND_Audio)
Pin 5 - 0
Pin 6 - 0 (SGND)
Pin 7 - 0
Pin 8 - 3.2V (AC_DET)
Pin 9 - 5v (PS_On)
Pin 10 - 0 (PNL_POW)
Pin 11 - 0 (SGND)
Pin 12 - 5V (BU5V)

With Pin 9 and 12 Jumpered.

Mike

[R_J]

Re: Sharp LC-C4655U Flashing OPC and Power lights.

Check the back of the board for IC9703 (BU5V to B3.3v) regulator, that feeds Q9701 (lower left corner in picture)
One other thing to check would be if Q9702 is being triggerd by the OV_VLT line
LC42d65u service manual has the schematic of the main board

Did you check that both fuses are ok on the inverter board?

[berrmich]

Re: Sharp LC-C4655U Flashing OPC and Power lights.

I don't see IC9703 or Q9701 on my main board. Yes I am getting INV60V and 12V with the jumper.

My main board is KE716 XE716WJ

Thanks!

[berrmich]

Re: Sharp LC-C4655U Flashing OPC and Power lights.

Picture.

[berrmich]

Re: Sharp LC-C4655U Flashing OPC and Power lights.

Pin 5 on IC9703 reads 3.3V
Not sure how to check the second thing you said.

I did not see fuses there. I checked the one on the power board.

[R_J]

Re: Sharp LC-C4655U Flashing OPC and Power lights.

Something may be causing the power suuply not to turn on, It may be due to an error from the inverter board. If you force the tv ON with the button combination, do you have the inv12 and inv60v? if you do and you don't have backlights, the fault may be on either the inverter or maybe a bad ccfl or bad ccfl connection in the panel. and NOT the main or power supply boards.

Fuses on inverter board are in front of plug LA (post 4 second picture) Check for voltage (60v) on L7500A and L7501A

Q9701 should have 3.3v on pin4 and when the power button is pressed pin3 should also be 3.3v, Pin 2 should also change when the power button is pressed