Sharp 70" LC-70LE734U : No Picture : 2 Slow - 3 Fast

[Inverted]

I took a chance and picked up this tv for $150 in the hopes that I can get it working and can upgrade my 55" plasma(which was also a tv I repaired). So let the games begin!

Anyways, I've read through all of the posts I could find on the 70" Sharp.

The blink code I am getting is 2 slow, 3 fast.

I am getting nothing on the screen, I've never been able to get any backlighting, not even a quick flash. Many times I've taken a flashlight to the screen, but I get nothing.

I have 2 ribbon cables that leave the TCON and go to the lcd. I've attempted disconnecting the ribbon cables individually as well as both at the same time, I get nothing on the screen and no backlighting either. I also noticed that I am not getting any 12V, which explains why the screen isn’t coming on. Since it seems in some posts that the TCON is shorting out the 12V signal, I also attempting completely disconnecting the TCON and still get no 12V reading. In fact, the pinout voltage information below was taken with the TCON completely disconnected. I purchased a replacement power board and the tv exhibits the same behavior and voltage readout info regardless of what board I use. I am not ruling out that the same issue exists on both boards, but doubtful.



Part Numbers for all boards in the tv
---------------------------------------------------------------------------------------------------------
Power Board : DPS-228CP, RDENCA442WJQZ
TCON Board : DLNTKF778WE11/(A)
Main Board : QPWBXF733WJN2, KF733, FM24S
Address Board : DPS160WP(A), KA842WJZZ
---------------------------------------------------------------------------------------------------------


Here is the pinout information as taken from the power board(DPS-228CP, RDENCA442WJQZ)
---------------------------------------------------------------------------------------------------------
PD(V)

1. 0 : PNL_12V
2. 0 : PNL_12V
3. 0 : SGND
4. 0 : SGND
5. 13.03 : UR13V
6. 13.03 : UR13V
7. 13.03 : UR13V
8. 13.03 : UR13V
9. 0 : SGND
10. 0 : SGND
11. 0 : SGND
12. 0 : SGND
13. 3.32 : AC_DET
14. 2.85 : PS_ON
15. 5.06 : BU+5V
16. 0 : PNL_POW
17. 0 : VSYNC
18. 0 : SCL
19. 0.15 : NC
20. 0 : SDA
21. 0 : OFL
22. 0.3 : ERROR
23. 0 : NC
24. 0 : STB

LA(V)

1. 0 : SGND
2. 0 : STB
3. 0 : OFL
4. 0.3 : ERROR
5. 0 : NC
6. 0 : SDA
7. 0 : VSYNC
8. 0 : SCL
9. 13.03 : UR13V
10. 0 : PNL_POW
11. 0 : SGND
12. 0 : SGND
13. 0 : SGND
14. 0 : SGND
15. 65.3 : LED_VCC
16. 65.3 : LED_VCC
17. 65.3 : LED_VCC
18. 65.3 : LED_VCC

---------------------------------------------------------------------------------------------------------


The next post will contain detailed pictures.

[Inverted]

Re: Sharp 70" LC-70LE734U : No Picture : 2 Slow - 3 Fast

First round of attachments.

I've named the images to tell which part of the board they represent. As an example, if we take Power_Board_Front_Top....this means that it is obviously the Power Board, it is the front side of the board, as well as just the top portion of the board.

If it was Power_Board_Front_TopLeft, it would mean that it is the front of the board, but only displaying the top left. There would then be 6 images that made up the entire front side of the power board....front left, front right, middle left, middle right, bottom left, and bottom right. Hope this makes sense.

1. Sharp_LC70LE734U_Back
2. Power_Board_Front_Full
3. Power_Board_LA_Connector
4. Power_Board_PD_Connector
5. Power_Board_Part_Number
6. Power_Board_Front_Top
7. Power_Board_Front_Middle
8. Power_Board_Front_Bottom
9. TCON_Board_Front_Full
10. Main_Board_Front_Full

[Inverted]

Re: Sharp 70" LC-70LE734U : No Picture : 2 Slow - 3 Fast

Second round of attachments.

1. Power_Board_Front_Full_CameraFlash
2. Power_Board_Back_TopLeft
3. Power_Board_Back_TopRight
4. Power_Board_Back_MiddleLeft
5. Power_Board_Back_MiddleRight
6. Power_Board_Back_BottomLeft
7. Power_Board_Back_BottomRight
8. Address_Board_Front_Full
9. Power_Board_Back_Full

[Inverted]

Re: Sharp 70" LC-70LE734U : No Picture : 2 Slow - 3 Fast

Third round of attachments.

1. Main_Board_Front_TopLeft
2. Main_Board_Front_TopRight
3. Main_Board_Front_MiddleLeft
4. Main_Board_Front_MiddleRight
5. Main_Board_Front_BottomLeft
6. Main_Board_Front_BottomRight

[Inverted]

Re: Sharp 70" LC-70LE734U : No Picture : 2 Slow - 3 Fast

Fourth round of attachments.

1. Main_Board_Back_TopLeft
2. Main_Board_Back_TopRight
3. Main_Board_Back_MiddleLeft
4. Main_Board_Back_MiddleRight
5. Main_Board_Back_BottomLeft
6. Main_Board_Back_BottomRight

[dskall]

Re: Sharp 70" LC-70LE734U : No Picture : 2 Slow - 3 Fast

You read this post? https://www.badcaps.net/forum/showthread.php?t=50180 . Same blink codes

[Inverted]

Re: Sharp 70" LC-70LE734U : No Picture : 2 Slow - 3 Fast

@dskall,

Yep, I've read it. In order to get the pinout readings from above I used the vol+ & ch- trick, this gives me a solid boomerang light instead of the 2 long, 3 short error code. I've also held the power button and caused the light to go off, but unlike the originator of that post, mine did not miraculously start working

I've also tried the vol- & input trick, but that does nothing for me.

[Inverted]

Re: Sharp 70" LC-70LE734U : No Picture : 2 Slow - 3 Fast

Is it an issue with the PD connector which runs to the main board, showing 0.3V on the ERROR pin?

If I jumper this to ground through a resistor, is there any potential harm in doing this?

If I do jumper it, can I do it after I power up the tv, or do I need to have the jumper in place before I power on the tv?

[Inverted]

Re: Sharp 70" LC-70LE734U : No Picture : 2 Slow - 3 Fast

I made progress. I figured it was most likely the main board not allowing the 12v to come up, so I ordered a used main board. Now I get a 1-1 error code. Bypassing the error code with vol+ channel- I get the tv to start up. However, I've attempted several different methods of entering the service menu that I've found on this forum and none seem to work. I'd like to get into the service menu to attempt to reset the lamp error counter. Any ideas?

[mmartell]

Re: Sharp 70" LC-70LE734U : No Picture : 2 Slow - 3 Fast

Then you've tried holding Input/Vol- while plugging in ? Try Menu-2-4-8-9, it won't get you into service mode but if it works you can try a factory reset.

[Inverted]

Re: Sharp 70" LC-70LE734U : No Picture : 2 Slow - 3 Fast

Yep, I've tried Vol- and input while plugging in, as well as menu 4725, as well as menu 999,222. When I plug in the set normally it immediately goes to flashing 1-1. However, if I use Vol- and input while plugging it, it goes solid for 7-8 seconds, nothing comes on the screen, and then it flashes 1-1.

So I just tried menu 2489. What am I supposed to see happen? I hit menu on the remote and it obviously brings up the tv menu, then when I hit 2, it starts acting like I am entering a channel to go to, once I enter 2489 and then wait about 2 seconds it just goes back to displaying the current channel number that it is on.

[vinceroger69]

Re: Sharp 70" LC-70LE734U : No Picture : 2 Slow - 3 Fast

just read this in another thread (same set as yours) maybe worth speaking too the sellewr of the mainboard too see if they have another as you cant seem to re set it

new mainboard showed up with a 1-1 error. According to the service manual, everytime the error is thrown, it triggers a counter. If the counter gets to 5 without being reset in the service menu, it looks like the main board needs to be replaced.

[Inverted]

Re: Sharp 70" LC-70LE734U : No Picture : 2 Slow - 3 Fast

Is that listed in a service manual somewhere? That seems like the dumbest design ever. If it throws a 1-1 5 times the board can never be reset period?

[vinceroger69]

Re: Sharp 70" LC-70LE734U : No Picture : 2 Slow - 3 Fast

can be re set in service mode but as you cant access it not sure how you can go about it would a firmware update help?

[Inverted]

Re: Sharp 70" LC-70LE734U : No Picture : 2 Slow - 3 Fast

I actually updated the firmware yesterday in hopes that it would fix the issue. So how do I know that the issue doesn't still exist with my backlighting and that putting in a brand new board won't start throwing the 1-1 again?

[vinceroger69]

Re: Sharp 70" LC-70LE734U : No Picture : 2 Slow - 3 Fast

if you could get into the service menu i think all would be fine once reset i just dont understand why it wont let you access it.

[vinceroger69]

Re: Sharp 70" LC-70LE734U : No Picture : 2 Slow - 3 Fast

Yep, I've tried Vol- and input while plugging in, as well as menu 4725, as well as menu 999,222. When I plug in the set normally it immediately goes to flashing 1-1. However, if I use Vol- and input while plugging it, it goes solid for 7-8 seconds, nothing comes on the screen, and then it flashes 1-1.

So I just tried menu 2489. What am I supposed to see happen? I hit menu on the remote and it obviously brings up the tv menu, then when I hit 2, it starts acting like I am entering a channel to go to, once I enter 2489 and then wait about 2 seconds it just goes back to displaying the current channel number that it is on.

in the tv menu settind does it say factory rest?

[Inverted]

Re: Sharp 70" LC-70LE734U : No Picture : 2 Slow - 3 Fast

It has a reset under "initial setup" and "picture settings" in the menu. I've attempted to reset both of them. Under initial setup reset it asked for a 4 digit pin code from the prior user, which I didn't have, but I found a way to override that in the user manual. It basically just reset all the saved channels and whatnot.

I just threw the original main board back in, goes back to throwing the 2-3 error.

[budm]

Re: Sharp 70" LC-70LE734U : No Picture : 2 Slow - 3 Fast

I would like to know that DCV do you get at the ERROR pin of the PD connector now when the TV is working.
I believe it should be >3VDC when there is no ERROOR occur if I am right, I am trying to verify.
It is related to this one:
https://www.badcaps.net/forum/showthread.php?t=60015

[Inverted]

Re: Sharp 70" LC-70LE734U : No Picture : 2 Slow - 3 Fast

HAH! @budm I actually had that thread open and I was comparing the voltages. I'll have an answer for you shortly.