LC 65LE643U no video

[mars11]

Got this tv. sharp lc 65le643u without video or sound . Power up and back-light work. Screen start to get white from center to edge 3-4 seconds after start.
My dilemma start after i replace main board (used) based on fact that was no sound, no video. Replace board and i think tv start when i plug in the power cord.I can see on screen (right upper side) text" no signal" and i turn back to plug a hdmi cord . When i look back i can see the screen get white again ,still
with this board i have sound .
i order a t-con board that does not change anything . anybody run in this problem? Should i return that main board that look it fail .
main board voltage (19v) is 19.46V ; 12V for t-con is ok .
The screen look good also . i have a voltage regulator on main board (the replacement) 5v to 3.3 that is not working. Thanks for any advice


https://www.badcaps.net/forum/attach...1&d=1485104578

.https://www.badcaps.net/forum/attach...1&d=1485104592

https://www.badcaps.net/forum/attach...1&d=1485104592

[dskall]

Re: LC 65LE643U no video

Did you have white screen problem originally or after mainboard replacement? Do you have voltage on both sides of fuse on t-con

[mars11]

Re: LC 65LE643U no video

With the old board i did not have sound or video and the screen is changing white slowly ,the same with the replacement main b. even i have sound. I change t-con board and nothing change. Yes i have 12v after fuse on both t-con . Not sure if the white screen is the the result of defective main or i need to look/check something else before i decide to return the board. hard to believe that both t-con are defective but possible. Trying to find service manual also .Tomorrow i check more on main board thanks .

[mars11]

Re: LC 65LE643U no video

With the old board i did not have sound or video and the screen is changing white slowly ,the same with the replacement main b. even i have sound. I change t-con board and nothing change. Yes i have 12v after fuse on both t-con . Not sure if the white screen is the the result of defective main or i need to look/check something else before i decide to return the board. hard to believe that both t-con are defective but possible. Trying to find service manual also .Tomorrow i check more on main board thanks .

[mmartell]

Re: LC 65LE643U no video

Unplug one side of tcon at a time and post results.

[mars11]

Re: LC 65LE643U no video

Unplug left side bottom cable ( to screen) that side of screen remain dark and the other half get white . With the right side disconnected, right side screen remain dark the other side get white.
when i disconnect the top cable (from main b.) left side , the screen get white . when disc. right side- screen stay dark(that is the side that power the t-con). -

[mars11]

Re: LC 65LE643U no video

I mention that i am missing a 3.3v on the replacement board (main), i am not sure how that happen. it is the UP18, that circuit should drop 5v to 3.3v and feed UP4 3.3v to 1.8v .serial on circ. is RSAIH or RSAHU ( different board). Can't find this online any suggestion ? that circuit is defective for sure.

[dskall]

Re: LC 65LE643U no video

Have you tried swapping 3.3v reg from old board?

[mars11]

Re: LC 65LE643U no video

Not yet ,on replacement board i have 60 day warranty and if i do that probably i will void that. waiting for a service manual found on "paradise manual.

[dskall]

Re: LC 65LE643U no video

You could apply external 3.3v voltage and see if it works

[mars11]

Re: LC 65LE643U no video

I think about that .I will try and post back. Found the actual part name LA8013ACD.I search for it with little success.

[mars11]

Re: LC 65LE643U no video

Back with good news . I connect 3.3V from an external p.s.u and video work. Had to replace the LA8013 defective with one from old board, did that and work . Thanks for feedback . Problem solved.

[Shane711]

Re: LC 65LE643U no video

WOW, I have the same problem and I am shocked to see mars11 fixed it. That gives me hope. I thought for sure the screen was gone, but I do have a line in it I hope I can fix it with some brain surgery. OK, so I have 3.3 volts at UP4 and I have 1.8 Volts coming out so I am guessing my T-Con board is bad. Here is a video of it, I would like some feedback. Thank you. https://youtu.be/zDhK1EHwynM