Re: Sharp LC-80LE844U Blinks 2 slow, 5 fast

Update - I couldn't walk away from it...Don't those type of projects just drive you nuts?

I got the frame separated and can get to the buffer strips without as much hassle as I expected. Visual inspection looks fine. I traced the line connected to the pin I covered up on the ribbon cable. It looks like it traces directly to one of the ribbons connected to the panel. No components that I could potentially replace. So we're down to the physical panel or the unlikely tcon board.

It kind of bugs me to put this much...

Re: Sharp LC-80LE844U Blinks 2 slow, 5 fast

I was able to devote a little more time to this today hoping to narrow down the problem. I used the tape trick to try to isolate where the issue is. Turns out that as long as pin 72 (9th from right edge of ribbon cable when looking at contact side) is covered, the TV powers up. Looks like crap (odd colors/saturation and focus) on the left half, but it operates.

To me, this strongly indicates that it is a panel/buffer board issue, but I suppose there is still a possibility of a circuit issue on the tcon that is hidden when...

Re: Sharp LC-80LE844U Blinks 2 slow, 5 fast

I glanced through the thread, but not in full detail. That all looks fairly similar, but obviously for different models, so the mosfets mentioned don't apply and none of the mosfets on this board appear to be burned or test poorly in-circuit.

Based on what I saw there, I did see a post or video (can't find it again now) where they were able to diagnose the panel by testing resistance at the tcon board. I can't seem to find any comparable documentation for this panel, though. I'd like to do that before I order a tcon board...

It's been a while since I've checked in here or needed input on narrowing down what to replace on a TV repair, but I've got one on my bench now that has me wondering. The lack of part (board) availability means I may need to do some component-level diagnostics, and a second opinion is always good when it comes to that.

The issue - Sharp LC-80LE844U does not display. Power light comes on for a while, then you can hear a relay click off and the light blinks twice slow, then five times fast. Service manual points to 'Panel Power Supply Error' with this code, but isn't much more help...

Re: 42PFL3704D/F7 No picture

I can do some component-level troubleshooting with a little direction, but it seems like it's rarely worth the time anymore, and I don't have an oscilloscope or SMD equipment.

A $25 T-Con board is cheaper than spending much of my time troubleshooting, considering that board seemed to be the resolution for someone else with the same problem, so I took the gamble. If I could diagnose with some confidence which of the other boards or components is also causing issues, I would fix it. Cheaper than a new one, and there is nothing available...

Re: 42PFL3704D/F7 No picture

I apologize for digging up this old thread, but since I am new here, I can't start my own until after I post this...

I am working on a 42PFL3704D/F7 with this same issue - powers on, backlight fires, no picture, but sound comes through. As it appeared that a new T-Con board should give a picture, I ordered one and installed it. The backlight flickered a few times, then turned on. Within a few seconds, it started smelling hot and before I could unplug it, it started smoking. I tried putting the old T-Con board, and it started getting hot...