Sharp LC60E79u 2 blinks power/3 Blinks OPC

[Anzio]

I have a Sharp LC-60E79U with the blinking light error (Power and OPC blink 2 times together then OPC blinks 1 time. I read the previous thread on Sharp lc60e79u (https://badcaps.net/forum/showthread.php?t=66913&page=3) with this same issue, but no resolution was posted.

The service manual indicates this as a “DET_5V (33pin) error (L). 5V is not applied.”

I cannot enter service mode by pressing input and channel down and plugging the unit in to power outlet. However, I can override and enter the diagnostic mode if press channel down and volume up and plug the unit into power outlet, I can get a steady power light but back light does not comes on. Nothing happens when I press power and holding power turn unit off (no power light). Pressing power again returns to the blinking light cycle. I measured voltage in the override state at the power supply and got the following values. I noted that there was no value at pins for S14.3V.

Any advice on next step would be appreciated.

Anzio.

SGND 0V = 0V
SGND 0V = 0V
PNL 12V = 0V
PNL 12 V = 0V

PNL_POW = 0V
BV5V = 5.0V
PS_ON = 3.0V
AC_Det = 3.1V
SGND 0V = 0V
SGND 0V = 0V
SGND5 0V = 0V
SGND5 0V = 0V
S14.3 V = 0V
S14.3 V = 0V
UR 14.3V = 14.3V
UR 14.3V = 14.3V

SNGD3 0V = 0V
SNGD3 0V = 0V
SNGD3 0V = 0V
SNGD3 0V = 0V
SNGD3 0V = 0V
INV 24V1 = 24V
INV 24V2 =24V
INV 24V3 = 24V
INV 24V4=24 V

[budm]

Can you upload your service manual? My service manual does not show error codes chart.
PNL 12V = 0V
PNL 12 V = 0V
PNL_POW = 0V

PNL_POW control signal from main board is not present so there will be no PNL 12 V for the T-CON board.

S14.3 V = 0V
S14.3 V = 0V
UR 14.3V = 14.3V
UR 14.3V = 14.3V
Are you 100% sure that S14.3V is not present? This Voltage is from the same out put of the power supply that produces the UR14.4V, you can see how the connections on the bottom side of the board.

Also read this thread for 2:3 blink code: https://badcaps.net/forum/showthread...harp+LC-60E79U

May be you should also provide the pictures of the whole backside of the TV showing all the boards.

[Anzio]

I will check readings again tomorrow take more pictures.

Attaching service manual form the precursor LC6077U which includes what was left out of the LC60E79U service manual. See page 6-19)of LC6077U for error codes 2 blinks power/3 blinks OPC.

[Anzio]

"Are you 100% sure that S14.3V is not present? This Voltage is from the same out put of the power supply that produces the UR14.4V, you can see how the connections on the bottom side of the board."

OK, I checked the S14.3V again and there is no voltage present. I'm attaching pics of the of the whole backside of the TV showing all boards and the bottom view of the Power Board.

Anzio

[Anzio]

Better picture of Power Board top view.

[budm]

Originally Posted by Anzio

"Are you 100% sure that S14.3V is not present? This Voltage is from the same out put of the power supply that produces the UR14.4V, you can see how the connections on the bottom side of the board."

OK, I checked the S14.3V again and there is no voltage present. I'm attaching pics of the of the whole backside of the TV showing all boards and the bottom view of the Power Board.

Anzio

Please look at the marked up I made that shows how 14.3V, UR 14.3V, and S14.3V are generated and how they are connected, as you can see the 14.3V is fed to inductors, one for the UR14.3, another one for S14.3V.
So for you to have UR14.3V but not S14.3V it means that you have open connection in that S14.3V path which you should be able to easily trace it with Ohm meter and visual inspection.

[Anzio]

Budm, I am so sorry I made a measurement error. After making measurements from the bottom of the Power Board S14.3 is present at the bottom solder with a reading of 14.3V.

However when I try to measure from top of board pin connector with a small probe inserted into the where the S13.3 cable connects, there is no voltage present. I wonder if I have a bad cable?

I also measured voltage on Main Board at PD (top of cable and at the pins connected to the board) and the following voltages were detected:

Main Board PD
Pin 1 - 14.3V (UR14.3V wire connected here)
Pin 2 - 14.3V (UR14.3V wire connected here)
Pin 3 - 14.3V (no wire connected here)
Pin 4 - 14.3V (no wire connected here)
Pin 5 - 0V (S14.3 wire connected here)
Pin 6 - 0V (S14.3 wire connected here)
Pin 7 - 0V (no wire connected)
Pin 8 - 0V (no wire connected)
Pin 9 - 3.1V
Pin 10 - 2.9V
Pin 11 - 5.1V
Pin 12 - 0V

I attached a picture of the Main board.

I'm a novice but working hard to learn.

Anzio

[budm]

Your posy # 1
" I measured voltage in the override state at the power supply and got the following values. I noted that there was no value at pins for S14.3V."
So why are you wasting time checking on the Main board connector?
It is obviously that S14.3V is fine so I cannot see why you say you do not have s14.3v at the power supply board, it is fine as far as I am concerned so do not waste any more time on S14.3V.
The connector pin of power supply is not made to match one end to another end.

[Anzio]

Thanks, any suggestions where to look next given the error code "DET_5V (33pin) error (L)?"

[Anzio]

Budm, you referenced in the earlier post to "Also read this thread for 2:3 blink code: https://badcaps.net/forum/showthread...harp+LC-60E79U." Would it be appropriate to take reading on the MOSFET q7120. RebRebel10 use a 330 ohm resister in trying to troubleshoot the Gate issue.