Sharp LC-70LE750U horizontal lines then no picture (Error code: 2-5 blinks)

[CLquasi]

As an owner of 70LE750U, I feel like a trainer of rarest pokemon, I could barely find any information on this model...

Anyway, I have this TV for about 18 months. The issue first appeared to be some distorted picture:



VIDEO: https://youtu.be/EC6z9kbRSBI

In the beginning of experiencing this issue, the picture would be fine for minutes after the TV is just switched on, then it gets worst and good picture would then only last for seconds. Now the TV goes blank when switched on, and the LED indicator gives the error of 2 long then 5 short blinks. According to the service manual from a similar model from another thread (LC60_70LE745U_C7450U_SM.pdf), it's the "Panel power supply error" error:

PANEL_POW
Panel 12V failure
Flashes fast 5 times

DET_PNL12V (34pin) failure (L). Panel power is not
applied.
Detection is started after turning on the panel power and
receiving command; the power is turned off by polling.

Based on the symptoms, I was assuming the issue is power supply related and hoping to resolve the issue by replacing the "Sharp RUNTKB118WJQZ (DPS-254BP-1) Power Supply / LED Board".. well, until I saw the Sharp TECHNICAL TIP 1541 from another thread:

Model :
Almost all Aquos TV’s

Sympton:
TV does not Power ON, exhibiting blink code of 2 Long & 5 Short

Cause:
Defective/Broken Panel, or Tcon defect

I am now unsure how to toggle the issue, it seems it could be the T-con board, power supply, or the worst case... the panel... Any idea what to do next? Any help would be appreciated.

[sordids999]

Re: Sharp LC-70LE750U horizontal lines then no picture (Error code: 2-5 blinks)

Posting pictures of the back of your tv showing the boards with clear pictures may help you more with fixing your problem

[paulstef]

Re: Sharp LC-70LE750U horizontal lines then no picture (Error code: 2-5 blinks)

Start by measuring the voltages coming from the power supply. 12V , 5V etc do you have those?

[CLquasi]

Re: Sharp LC-70LE750U horizontal lines then no picture (Error code: 2-5 blinks)

Posting pictures of the back of your tv showing the boards with clear pictures may help you more with fixing your problem

Thanks for your response. I just opened the back, there are 3 major boards I see:

[CLquasi]

Re: Sharp LC-70LE750U horizontal lines then no picture (Error code: 2-5 blinks)

Start by measuring the voltages coming from the power supply. 12V , 5V etc do you have those?

Hi, paulstef, I do have a multimeter, but I am not sure how to use it... I assume I turn to 20 under DCV? Where do I point the red/black pins to?

(I have done PC assembly and stuffs, I can replace boards, but I am no electrician... Sorry for my lack of knowledge.)

[paulstef]

Re: Sharp LC-70LE750U horizontal lines then no picture (Error code: 2-5 blinks)

Hi, paulstef, I do have a multimeter, but I am not sure how to use it... I assume I turn to 20 under DCV? Where do I point the red/black pins to?

(I have done PC assembly and stuffs, I can replace boards, but I am no electrician... Sorry for my lack of knowledge.)

Yes to 20V DC.

You can connect the black probe to the chassis, which is normally secondary ground. Then measure with the red probe.

[CLquasi]

Re: Sharp LC-70LE750U horizontal lines then no picture (Error code: 2-5 blinks)

Yes to 20V DC.

You can connect the black probe to the chassis, which is normally secondary ground. Then measure with the red probe.

Do I check those 2 spots?

[CLquasi]

Re: Sharp LC-70LE750U horizontal lines then no picture (Error code: 2-5 blinks)

While in process of learning and checking the voltages, I found...



Is that a blown fuse?

[CLquasi]

Re: Sharp LC-70LE750U horizontal lines then no picture (Error code: 2-5 blinks)

Nevermind, it's a ceramic fuse...

[tom66]

Re: Sharp LC-70LE750U horizontal lines then no picture (Error code: 2-5 blinks)

Given you're getting a 2-5 error code, which is panel-related, and a picture fault, I would say it is quite likely the LCD panel has failed - this would generally not be repairable (sorry)

[CLquasi]

Re: Sharp LC-70LE750U horizontal lines then no picture (Error code: 2-5 blinks)

Thank you for the reply... Yah, based on the error code, it does seem hopeless... I guess I was just waiting someone to hit me with the truth... 18 months... This is the shortest lived TV I have ever owned.... (What a shame... Even my 1997 Sony CRT still works like champ!)

Thanks.

[CLquasi]

Re: Sharp LC-70LE750U horizontal lines then no picture (Error code: 2-5 blinks)

Strangely, when I attempt to check the power supply, the TV turned on, the 2-5 code went away, but I still get distorted picture. Is it possible that the issue is somehow not the panel, or am I just beating a dead horse...?

I got 12.55 from the pin below, is that within the acceptable voltage?

[budwich]

Re: Sharp LC-70LE750U horizontal lines then no picture (Error code: 2-5 blinks)

did you do anything more with this? I (my friend) have a lc-70le757u with the same 2-5 code. The "shop estimator" basically indicated a "panel replacement". Got the service manual for the set but it doesn't include the schematic of the PD board (the others are there). I just got the set in a place that I can start with the disassembly but your statement about the sharp technical tip isn't very encouraging... :-(

I too, can't believe a set that is basically 1.5 years old has a panel failure from basically just sitting there. His set never had any picture problems and basically was turned off at the end of day and then next day, there was no "turn on".

One question, besides checking you voltage (which appears correct based on my reads), is have you removed the board and looked at the components on both sides to look for issues. The reason I ask, is top side things look fine but on the bottom side, there appears to be a diode (MUR260) that appears to have a "changed solder state" (ie. looks cold as opposed to the shiny others). Without the schematic, I don't know what that particular one does but there is a significant count of them on the board. I hope to start metering those along with some voltage checks as soon as I can figure out how to get at the connector pins safely.

[jetadm123]

Re: Sharp LC-70LE750U horizontal lines then no picture (Error code: 2-5 blinks)

Seen quite a few Sharp 70" failed panels on this forum. I wonder if all their 70" models are using the same panel?

[tom66]

Re: Sharp LC-70LE750U horizontal lines then no picture (Error code: 2-5 blinks)

I think the LE6xx and LE7xx have to be Sharp's least reliable models for sure.