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...
Robottom
Member
Last Activity: 08-08-2017, 12:34 PM
Joined: 06-25-2017
Location: HB, CA
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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....Leave a comment:
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Re: Little Help with Sharp LC-80LE642U
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....Leave a comment:
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Re: Little Help with Sharp LC-80LE642U
I only see a black rim around the LCD section.
I haven't taken that apart but have inspected it pretty carefully and there are no visible boards or cables.
Is it possible that the edge panels and cables are integrated into the LCD Panel Module Unit on this model?
Have a look at the Cabinet Layout attached.
These pages are extracted from the LC-80LE642U Service Manual
I don't see anything that I don't recognize in the PCB or Parts lists either.
At least the TV isn't complaining...Leave a comment:
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Re: Little Help with Sharp LC-80LE642U
No but she's threatening to make that one my permanent bedroom....Leave a comment:
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Re: Little Help with Sharp LC-80LE642U
I have been scratching my head and wondering what edge boards and corner cables were.
I found this ([url]https://www.badcaps.net/forum/showthread.php?t=49281&highlight=corner+cables&page=6[/url]) scroll down to #105 - 106, and some other threads which I think explain but I don't have any of those boards or cables.
Here's what my LED back panel looks like and here's what my LCD panel looks like. Although this pic is just one corner, believe me, there are no connections or boards except for the ones...Leave a comment:
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Re: Little Help with Sharp LC-80LE642U
Thanks for the encouragement, I'm pushing back.
I finally decided to hire someone to come out and help troubleshoot.
Drops another $50 into the bucket but if I can get it working beats the heck out of $2K or more.
I bought the tester several posts back, the exact same one in your link.
That's what I used to test and post the results that the LED strips were reading 174 - 175VDC.
ALSO .... I'm still curious about your (Martino) previous comment about chips burning up, pulling...Leave a comment:
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Re: Little Help with Sharp LC-80LE642U
With
BUSV (pin 15) jumped to PS_ON (pin 14) through 1K Ohm resister,
STB (pin 24) jumped to PS_ON (pin 14) through 1K Ohm resister and
PNL_POW (pin 16) jumped to PS_ON (pin 14) through 1K Ohm resister
I get a short flash of the LEDs at power up and again at power down.
Nothing seems to keep the LEDs on longer than a short flash.
Are there any other tests than powering the strips with the LED tester that I can run on the LED strips to be 100% sure that they're not one and only problem?Leave a comment:
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Re: Little Help with Sharp LC-80LE642U
Question... Assuming that I can get the power board to light the LEDs without being connected to the main board, where do I go from there?
I've already replaced all three boards and have exactly the same symptoms as from the beginning.
Assuming that the boards are OK, something else must be wrong.
Example: overcurrent from the LEDs or possibly LCD panel error of some kind via TCon. (would mean that the flashing icon 1 short 1 long is misleading).
Are there any chips or components in the...Leave a comment:
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Re: Little Help with Sharp LC-80LE642U
Just trying a couple of things to get the LEDs on using the power board, I went back to this idea that I talked about earlier: See attached pic.
This guy actually powers up STB as well as PS_ON from BU5V but no resistor.
Anyway same as what you said he's also powering something else PWM1.
But I don't see anything on this power board with those markings or the markings BL_ON you mentioned.
I tried powering STB through the resistor from BU5V too and still same, no LEDs lighting up.
...Last edited by Robottom; 07-24-2017, 01:50 PM.Leave a comment:
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Re: Little Help with Sharp LC-80LE642U
With BUSV pin 15 jumped to PS_ON pin 14 through 1K Ohm resister, I'm still not getting the LEDs to turn on, and measuring only 14 - 15mV at STB pin 24....Leave a comment:
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Re: Little Help with Sharp LC-80LE642U
Nothing, the power board doesn't even try to output to the LEDs.
There must be some other signal from the main board that tells the power board everything is OK. Do you know what other signals from the main board I would have to fake?
And as for being no expert, I'm sure that I have you way beat, thanks anyway!! :-)Leave a comment:
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Re: Little Help with Sharp LC-80LE642U
No, I asked if there was a way to do that in my original post, "Fool the power board" but didn't get any feedback.
Will go try that now and let you know what happens.
Thanks...Leave a comment:
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Re: Little Help with Sharp LC-80LE642U
BUMP
Does any one know what / where these chips are that Martino mentioned?
If there's an easy fix of any kind, I'll give that a try but pretty much tomorrow is the end game for this thing. I promised we'd have our TV back by then, so it's off to Costco for a new one and parts for sale after that.
Thanks,
TomLeave a comment:
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Re: Little Help with Sharp LC-80LE642U
This all started after a power outage, is it possible that both side chips blew out at the same time?
Where are the chips located?...Leave a comment:
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Re: Little Help with Sharp LC-80LE642U
Disconnected left ribbon cable from the tcon, reset start.
Got one bright flash of the backlight LEDs and a few seconds later the power board shut down and the icon light returned to blinking. (Same as previous)
Reconnected left ribbon cable disconnected right ribbon cable, reset start .... same as previous.
Disconnected both ribbon cables, reset start ..... same as previous.
Disconnected cable between main and tcon reset start got one bright flash of the backlight LEDs but the power board stayed...Leave a comment:
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Re: Little Help with Sharp LC-80LE642U
OK, well here's my last attempt asking for help. The wife is loosing it. I'm going to have to literally pull the plug and buy a new TV if this doesn't work.
After all of the above, I broke down and bought a refurbished Main Board, no joy.
Figured what the heck I'm this far into it, bought a used but good TCon board, still no joy.
Last ditch effort I repined L2 to match what the power board says and still no joy.
(note from above the mismatch between board as marked and L2 as pinned)
So, to...Leave a comment:
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Re: Little Help with Sharp LC-80LE642U
Thought I'd try something on my own while waiting for a some feedback on signals posted previously.
I unpinned PD - 22, the ERROR signal and tried resetting, (plugging in with "Input" & "Vol -" held down). I was hoping that the lack of the ERROR signal would allow the power board to light the backlight LEDs and keep them lit. Unfortunately it didn't change anything so I have to assume that the power board is not seeing some signals in whatever order it wants or it's detecting some error on it's own that...Leave a comment:
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Re: Little Help with Sharp LC-80LE642U
These readings were taken with the LCD panel disconnected.
The only way I could get "Power On" was to repeatedly keep resetting.
Meaning that I would unplug, hold "Input" & "Vol -" and plug back in.
The LEDs would all flash on then go out and power would only stay on only for a few seconds.
Then the power board would click and the Icon light would start flashing again.
Also, not below, I might have missed pin 16 PNL_POW on the on tests.
I have it recorded...Leave a comment:
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Re: Little Help with Sharp LC-80LE642U
Performed three different checks this morning, no other indication than normal. Running out of ideas.
Connected backlight tester black lead to chassis ground.
Then put red lead on every connected pin on L1 to see if anything lit up. Nada.
Tested continuity from every connected pin on L1 to chassis ground. Nada.
Tested continuity from every connected pin on L2 to chassis ground. Nada.
Just as a follow up, here's pictures of the connectors and actual pinout verses what's marked on the board....Leave a comment:
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