Sharp LC-70UQ17U won't power on, 3 long-1 short blink

[emilime75]

Hello. Hoping you guys can give me a hand here. TV was replaced by our service department and was going to be thrown away, so I took it home to see if I can get it working. I work for an AV integrator and the customer called us because the TV failed to power on. We don't repair TVs, and it's out of warranty, so the decision was made to replace it. The techs who went out on the call couldn't get much out of the client as far as info on any other symptoms prior to it not turning on anymore.

Once I got it home and plugged it in to power, it seemed non responsive and no blinking lights. A few minutes after trying to turn it on, it began flashing 3 long, 1 short. Doing a bit of reading around the web, I was quick to make the call that it's most likely a power supply issue, so I ordered a replacement from an online vendor who sells used but "tested" boards. It came today and I installed it as soon as I got home from work...no go. Still the same 3 long-1 short flash. Found a few different button press/apply power sequences, and Vol+, Ch- seemed to have cleared the trouble codes, but TV still would not turn on. After making what I think was 5 attempts to turn it on, the 3 long-1 short flash came back. I also tried shining a light on to the screen to see if any image would be visible, but I did not see anything(could have been doing this wrong).

Can anyone assist in troubleshooting this further?

I've tried uploading photos, but I keep getting a "This PNG image has the incorrect file extension." message. Looking into getting that resolved.

[emilime75]

Re: Sharp LC-70UQ17U won't power on, 3 long-1 short blink













Finally figured out how to attach photos.

[budwich]

Re: Sharp LC-70UQ17U won't power on, 3 long-1 short blink

unplug the cable going to the tcon and see if the blacklights come on either normally or thru force sequence.

[rddube]

Re: Sharp LC-70UQ17U won't power on, 3 long-1 short blink

Tried to upload the service manuals but the files are too large. You can get them here:

https://elektrotanya.com/sharp_lc-60.../download.html

The error code you are referring to seems to be this:

3) Communication failure details (Flashes slowly 3 times and flashes fast)

which sounds more like the main board.

[emilime75]

Re: Sharp LC-70UQ17U won't power on, 3 long-1 short blink

unplug the cable going to the tcon and see if the blacklights come on either normally or thru force sequence.

Yes, I've been doing some more troubleshooting based on yours and freakaftr8's posts.

Got an image to display with issues. I'll do it again and snap photos, and I'll likely also shoot and upload a video to youtube because it's doing some rather strange things.

Two of the symptoms I'm seeing with the tab driver ribbon cables disconnected at either the bottom left/bottom right corners of the panel is...

A. Image is "laggy", on the right side when the image changes a part of it lingers on the TV and slowly fades away.

B. Distortion lines appear all over the panel, but they fade in over time...meaning, turn TV on, backlights fire, no image, but different colored lines slowly fade in to the panel.

I'll come back with better documentation, I know the above doesn't explain it well.

[Michaels3e]

Re: Sharp LC-70UQ17U won't power on, 3 long-1 short blink

Hi guys, I have a question about a sharp TV M# LC-60UD27U This TV when plugged in the front light will stay steady for about 1 to 2 mins and then it goes into the blinking... here's the thing.. it will blink 2 times slow and then 7 times fast .. I cannot find anything on this code I called sharp and they just had me do the reset and the hard reset I think all the resets ave been done but I cannot find anything on this code 2 blinks slow 7 blinks fast .. hope someone can help .. Thank you .. Michael