Sharp LC-52LE640U - DET_PNL12V failure

[budm]

Re: Sharp LC-52LE640U - DET_PNL12V failure

One of these is your board.
http://www.shopjimmy.com/catalogsear...=QPWBXF975WJN1

[Snwboardr9876]

Re: Sharp LC-52LE640U - DET_PNL12V failure

Here is the label:





Also, I have 12v to ground on both sides of this...

[budm]

Re: Sharp LC-52LE640U - DET_PNL12V failure

OK that looks like low Ohm resistor. I still cannot see the fuse on that board yet, but at least we know that it is receiving the 12VDC feeding the board but we do not know if all the sub power supplies on that T-CON boards are working or not.
There are so many version of the KF975. Your looks to be 'FM08'.
Try disconnecting the two white ribbon cables going to the LCD panel to see if the error will go away.

[Snwboardr9876]

Re: Sharp LC-52LE640U - DET_PNL12V failure

So should my next move be purchasing a new T con board and swap it out?

[budm]

Re: Sharp LC-52LE640U - DET_PNL12V failure

Try disconnecting those two ribbon cables going to the LCD panel to see if the error will go away first.

[Snwboardr9876]

Re: Sharp LC-52LE640U - DET_PNL12V failure

The two big ribbons on the bottom of the board?

[newtothis]

Re: Sharp LC-52LE640U - DET_PNL12V failure

yes the 2 next to each other

[Snwboardr9876]

Re: Sharp LC-52LE640U - DET_PNL12V failure

Okay that's what I thought, yes I already tried this in the beginning. Removed one at a time and saw no change in my outcome and tried with both disconnected as well.

[budm]

Re: Sharp LC-52LE640U - DET_PNL12V failure

Well, I would say try new T-CON board then. I hope the Sharp error code is correct.

[Snwboardr9876]

Re: Sharp LC-52LE640U - DET_PNL12V failure

Just finished swapping in the new T-con board. Got something different. Plugged it in and received the same flash code. Hit the power button and some very faint lines came up vertically across the lines. I mean you could BARELY see them. This lasted for a about 5 seconds before they went off and the led went back to flashing again.

During the time that the lines were on there, there was also a faint buzzing noise. I was able to replicate this whole process 5 times in a row and then all of a sudden it stopped doing that. Now it's back to totally blank black screen for 10 seconds when I hit the power button and then back to flashing.

Again, here's the meaning for the code

Anybody have any suggestions?

[budm]

Re: Sharp LC-52LE640U - DET_PNL12V failure

Since it acts different, try disconnecting the cable to the LCD panel again.
The buzzing sound remind me of the bad panel (LG) that causes the inductor on the T-CON board to buzz.
I hope the panel did not damage the new T-CON.

[Snwboardr9876]

Re: Sharp LC-52LE640U - DET_PNL12V failure

I tried disconnect each ribbon cable again but I didn't get to try it until after the lines didnt come up any more. It made no difference when I disconnected the cables. I have a feeling it may have ruined the TCon board like you said.

Okay so I have a question, when I hit the power button and the LED turns solid for 10 seconds and I'm able to read all my voltages, what would be causing it to disappear after the 10 seconds?

The "note" says "the power is turned off by polling" any idea what that means?

[budm]

Re: Sharp LC-52LE640U - DET_PNL12V failure

I have no idea on how this TV goes about detecting and polling the errors.

[Snwboardr9876]

Re: Sharp LC-52LE640U - DET_PNL12V failure

Any other thoughts on where to go from here?

[budm]

Re: Sharp LC-52LE640U - DET_PNL12V failure

Nothing, I think your panel has shorted circuit some where that takes out the T-CON board.

[newtothis]

Re: Sharp LC-52LE640U - DET_PNL12V failure

I have to agree with budm, The lines coming up like they did and then the set failing to pre-board swap says the panel is defective.

[ggil44]

Re: Sharp LC-52LE640U - DET_PNL12V failure

Sorry to resurrect this one more time but I also have a LC-70LE650U with the same symptoms, 2 blinks, 5 winks. I read the posts and tried disconnecting the ribbon cables from the t-con to the panel and found the led lights came on. I looked for any cracks but did not find any. I unplugged the set and then I reconnected the right side ribbon connector (as you view it from the back of the set) and the same side of the panel came on and generated a raster. Then unplugged, I then connected the left side ribbon cable and got the 2 blinks and 5 winks. So I again unplugged and only connected the left side ribbon cable and again got the 2 blinks and 5 winks. Any ideas where I should look (try) next?

Thanks in advance for the help

[budm]

Re: Sharp LC-52LE640U - DET_PNL12V failure

You have bad panel.

[ggil44]

Re: Sharp LC-52LE640U - DET_PNL12V failure

Ouch! Then there is no economical fix? The TV is just basically junk, right?

Well, thanks for the help. At least I won't have to spend a lot more time on it

[mp3car]

Re: Sharp LC-52LE640U - DET_PNL12V failure

Add me to the list with the 70". I just started another thread prior to seeing this one, but perhaps I should add a link to this thread and we should stick to this one since it's a similar issue. I say similar because I have seen symptoms that are slightly different...

I have a few more things to add... My set first started (with the previous owner prior to giving it to me) showing horizontal banding on the full screen, like "shadowed" bands across the image... Then, it went out and started the error code. He replaced the t-con board, but it still gave 2-5 code, I don't believe the set ever came back...

Fast forward 4 months, to now, after [presumably] sitting unplugged... I get it and hook up a source and the screen looks great! But 10 minutes later, the horizontal banding the previous owner saw showed up again. I shut it down and took off the back. I turn it back on and image is good again... While running, I checked temperature of various ICs. The ASIC on the t-con board was too hot to touch for more than about 5s. I "manually" cooled the IC (wetting tip of finger and touching the IC every few minutes), it ran for a good 30m no issues, I turned it off. Now come next evening (note, another variable, close lightning occurred this day, but no signs of any damage to any other devices in the house)... I turned it on, no sharp logo, backlit but blank (black) screen, just a second or so later, backlighting goes out, and no time for t-con ASIC to get warm. Then, with a dark screen 10s or so later, it gives me the 2-5 blink code. Note again, that the prior evening it ran for 30m with a perfect picture (I also reset settings and updated firmware while it was up).

Now for some troubleshooting... I have the 12v at the t-con until it declares error code... I disconnected both ribbon cables to panel and have full white screen, no error code. Running on either half alone (i.e. only one ribbon wire connected), I saw the same behavior regarding no code thrown, but now only half screen was white (the disconnected half) and the connected half was black (but full backlighting). Then, several power cycles later and various probing with my o'scope, I powered it on with only "side A" (right side when facing front of the panel) plugged in, now it showed right half of the sharp logo on the plugged in side of the screen, white on the left (unplugged side). I repeated this, alternating which half, and it was repeatable: the right half showed the last half of "sharp" when only side A plugged in, left half white, no code - I can see the right half of OSD menu, etc... I was hoping maybe I'm getting somewhere since previously these same steps resulted in the right half being black (but lit) and left white. I switch to only the left side plugged in and now right side is white, but black/blank left side (NOT the first half of "sharp" splash screen). I would suspect an issue with the t-con's left side drive, except, why would plugging in the right [apparently working] side of the panel (A) with the the left cause a shutdown, but not the left side alone, if the issue were to be with the left side of PANEL?

The question I asked in the thread I started, AND WHAT I AM ASKING NOW, is if the left and right drive out of the t-com board are the same pinout, which would allow me to drive the left half of panel with the right side (Side A) output of the t-con board, which I know works because it shows the right half if sharp... My expected result if panel is good would be that the last (right) half of "sharp" would be displayed on the left half of the screen, if the left half of the screen is good...

As I mentioned, it ran fine without any issues (other than the t-con ASIC running hot) for 30m... No apparent cracks. I have taken plastic bezel off and don't see any signs of damage to panel. I took left side black metal trim panel off the panel, and again, didn't see any signs if damage, but I have not taken other metal bezels off. The ribbon cables along the left side of panel (the white one at the bottom left corner where it rounds the corner from bottom to run up the left side, and the brown kapton ribbons between the two disconnect boards that run up the left side, and the ribbons between disconnect boards and panel) all appear fine.

One thing I wonder is if the left side of panel has issue (which is why I took front left bezel off), but why wouldn't having just the left side plugged in trip the error??? UNLESS, there is a problem with left side of panel, but it's not drawing enough total current from the t-con/ps that it shits down, BUT if the functioning right side is plugged in also, then it's too much of a draw and shuts down.

To reiterate what I said at the beginning, the previous owner already replaced t-con, but also as a reminder, it didn't work for him and just gave blink codes, but after sitting for 4 months (and being moved) it gave me a functioning picture...

Anyhow, if the left and right side are the same, that will be my next step... I would suspect maybe a panel problem caused left side driver to fail, but if that were the case, why did it still show failed for him, but then when I got it, it worked for me at first... I guess I need to verify with him if he still saw blink codes after replacing t-con, OR if he got the same result after running, and never ran it long enough to potentially kill left side drive of t-con... But did I really run it long enough to kill it since it worked all the way up until I unplugged it?