Little Help with Sharp LC-80LE642U

[Robottom]

Re: Little Help with Sharp LC-80LE642U

The reason that there is no listing for the boards is that they aren't replaceable as there is bonded cabling between the board and the panel which is a "one time assembly / manufacturer". Anyways, I would look closer at the edge especially going from the tcon to the panel at the bottom. Your issue may be related to how the edge boards are interconnected which could be good or bad depending.

OK, you're right there are boards and cables buried inside the plastic rim.
Unfortunately the plastic rim is sandwiched between the backlight panel frame and the LCD panel frame, screwed to the LCD panel frame.
The only way to get to the edge boards is to separate the LCD and backlight panels ... again.
That it's going to make it near impossible to stage the pieces somehow to have them all connected.
The Tcon ribbon cables aren't anywhere near long enough to set things where they'll fit in the room.
And there isn't enough room to lay everything out side by side.
Not to mention that I'm struggling to work up the courage take the two panels back apart again.
I think I'll wait until the new main board arrives, see if my money was well spent on the tv tech.
If that doesn't pan out, it's out to the garage at best, it'll be Goodwill or the trash if momma has her way.

[budwich]

Re: Little Help with Sharp LC-80LE642U

fingers crossed for the replacement main board.... :-)

not sure what to say but I wish you were on my street and garabage day was dry / not rainy... :-)

some people have had luck with reseating the cables that interconnect the edge boards. The "signal" travels along the bottom and then up each side. There are "clampable" flex / ribbon cables on those interconnections... some times they aren't set well for what ever reason... as you have found with the tcon cables, it can be hard to ensure perfect alignment. Further, some people have found capacitor blown on the edge boards that are somewhat "serviceable" albeit with not very much access... but still doable. Since your problem appears to have arrived with "powering" coming into your location, it is possible that there may be an issue there.
Anyways, not sure what else to say other than "here is hoping".

Lastly, your comment about access to the edge boards is somewhat wrong. I know from my work on a sharp 70 that you only have to deal with the bezel (black plastic) on the side and a removeable plastic protection / frame member along the bottom.... you don't have to seperate the leds from the panel. In fact, I was surprised that your went "there" (ie. led and panel seperated) on such a large panel.

[Robottom]

Re: Little Help with Sharp LC-80LE642U

Initially the reason I separated the halves was to test the LEDs, I couldn't see them to know if they were all working any other way.
After finally convincing myself they were not the problem, I put the two panels back together.

I'll look again to see if I can remove the plastic bezel without separating the panels. If you have done it that way, I'll certainly give it a shot. I do know that there are a separate set of screws holding the bezel. I can remove only those and see if it comes out exposing the edge boards.

Thanks for all the help. If I can't get it going I'll strip it for parts anyway. I have a friend with an 80" and I have a 70" in another room. So it won't go completely to waste. Just a shame and a waste of money.

Will let you know where I end up the end of the day Tuesday anyhow.

[Robottom]

Re: Little Help with Sharp LC-80LE642U

Well, the new main board showed up earlier this week, SOS DD, so I'm throwing in the towel.
I've completely stripped all of the parts, and need to recover a few dollars, so make an offer if you want otherwise eBay.
I will definitely put one set of boards up for sale and some of LED strips too.

The LCD panel is not physically damaged but I have to believe that it's the problem, nothing else seemed to change.
I looked at the edge panels but couldn't see anything that looked frazzled and all the connectors seemed tight.
Anyway, free, if anyone in the Orange County CA area would like to pick it up in the next few days, please PM me.
Same for the big metal and plastic mechanical parts.

If I don't get any requests will begin breaking those things down into small enough pieces to get into a trash can.

Thank you all once again for your help, and best of luck with any future projects.

Thanks,
Tom

[schem7]

Re: Little Help with Sharp LC-80LE642U

you have a bad panel... I have a 60" sharp here that would turn on and screnn flashed and out with no backlights. I did battery test on the LED`s and was all good. I then disconnected one of the ribbon cables from the t-con that was going down to the driver board and plugged set in... set came on and back lights stayed on. But I had half screen working and other half white. I then replugged that one and unplugged the next one... same thing everything worked.. I then replugged bot of the ribbon cables and I am watching the tv since yesterday with full screen. It indicates to me something is wrong on driver board. There is a way to fix the drivers and that is what I am searching for. I think once the drivers are replaced the set will be like new

[football0062]

Re: Little Help with Sharp LC-80LE642U

Was reading up one these 80" models last few days as i have come across the same issue. First its not a bad panel, even if it was it wouldnt have anything to do with the LEDS going into OVP. The issue is on the 80s there are 15 LED strips, but the LED driver has 16 channels. Channel 9 is used in only the 90" versions that use the same board, but because the 80" has one less channel that one is open. i could not find a datasheet on the LED driver chip but if you look at the 9th channel you will see it is the only one that has a sensing line on it returning back to the chip from the drain pin. This is Q7623 btw. and its R7Q07 that feeds that return. Now tricking the LED driver into thinking this pin is running normal by isolating the mosfet and connecting the sensing lines onto another set of pins is the correct way of doing this, but i have gone through 2 boards using a 70" versions to access the service menu, set the board to 80" and numerous amounts of models available, just to keep getting the same OVP with that set up. SO i set it to a 90" screen in the service menu, piggy back that sensing line for channel 9, and it works fine. would much rather not mess with jumper wires and do this correctly but even grabbing both the Nand and eeprom chips from the old original board(communications error, wouldnt boot) it still would give me the 1-1 code. I couldnt find the .USB and .MSB files needed to try and program fresh, but if someone out there has them and wants to send them my way i will give that a go as well and see if that does any good. i will attach picture of 9th channel mosfet and the jumpers i made.

[football0062]

Re: Little Help with Sharp LC-80LE642U

again though, the panel size on page 29 in the service menu needs to be set to 90! anything less it will still give you 1-1 and go into OVP

[football0062]

Re: Little Help with Sharp LC-80LE642U

here are the files