Sharp Aquos LC-52LE700UN No Sound No Picture

[johns1mj]

I received a tv with no history known. The tv will power on and the backlights will turn on. There is no display and no sound. Not even a logo or menu will display. I tried the input and volume down reset. The blue V will turn on at the bottom of the unit, however, there is no other change to the tv. I hooked up a rca cable connected to a controller with built in games to try to get anything. Obviously I can not determine what input I am on. I have tried to move through the inputs but no results. Next, I connected my phone by hdmi cable. With the tv off the phone will recognize all hdmi ports. With the tv on it will not recognize any hdmi ports. I was thinking a bad PCB board or logic lock. I unhooked the ribbon to the t-con board and the power and optical light will flash indicating some self diagnostic is still possible by the tv.

I have been shocked by TV's. I am a little gun shy about power testing. Any thoughts?

[dick_barton]

Re: Sharp Aquos LC-52LE700UN No Sound No Picture

Does it have a Scart input because many TV's normally recognised a scart signal input and automaticaly swithes over to it.

Service manual

[johns1mj]

Re: Sharp Aquos LC-52LE700UN No Sound No Picture

I do not believe so. But why would that prevent ANY display, no menu, no logo, nothing, just backlighting?
list of inputs.
HDMI®: 4 (v1.3 with deep color)
HD Component: 2 (1080p compatible)
Composite Video: RCA x 2
S-Video: 4-pin DIN x 1
Audio Inputs (L/R): 4 RCA
RS-232C: 1
PC: 1 (15-pin D-sub)
Ethernet Input: 1

[dick_barton]

Re: Sharp Aquos LC-52LE700UN No Sound No Picture

It's just a quick check for sound.
If you download the manual above it will give you instructions for fault finding. I've reached my daily limit for downloading.

[johns1mj]

Re: Sharp Aquos LC-52LE700UN No Sound No Picture

I have already been there. They are a nice reference tool but no aid in diagnosis since it only gives a wire schematic. No test procedures listed in the down load. Thank you though.

[dick_barton]

Re: Sharp Aquos LC-52LE700UN No Sound No Picture

Can you measure the DC voltages on the connector pins and give them with the labels printed alongside.

[johns1mj]

Re: Sharp Aquos LC-52LE700UN No Sound No Picture

I will try, but I have been shocked and fried boards trying this. I will get back after I have checked voltages.

[dick_barton]

Re: Sharp Aquos LC-52LE700UN No Sound No Picture

If you are not confident and are afraid you are getting shocks then may I politely suggest you take your set to the repair shop. It's better to remain alive than have a working set.

[johns1mj]

Re: Sharp Aquos LC-52LE700UN No Sound No Picture

Here are the voltages. Picture one should be the power to input board. Picture two should be power to t-con board. Picture 3 is another power to input board. Picture 4 is the connector on the t-con from the input board.

[johns1mj]

Re: Sharp Aquos LC-52LE700UN No Sound No Picture

This is the most service information I can find but it still doesn't have voltage references.

[johns1mj]

Re: Sharp Aquos LC-52LE700UN No Sound No Picture

I think I found my voltage references on page 8-2.

[budm]

Re: Sharp Aquos LC-52LE700UN No Sound No Picture

What are using for the GND ref point for the meter? Your reports showing Voltages on the GND pins, it has to be measurement error, and some of the readings also show in 100's of Volt! which cannot not be right.
For example:
https://www.badcaps.net/forum/attach...4&d=1462757515
PS-ON pin 10 is shown as 192 Volt?

Sharp RUNTKA604WJQZ (PSD-0697, QPWBS0286SNPZ(96)) Power Supply
http://www.shopjimmy.com/sharp-runtk...er-supply.htm#

Pictures provided by shopjimmy.

[budm]

Re: Sharp Aquos LC-52LE700UN No Sound No Picture

BTW, did you see any error codes?

[Kilroys]

Re: Sharp Aquos LC-52LE700UN No Sound No Picture

This RUNTKA611WJQZ is for LC-52LE700 and 52LE600 european and russia market
The manual should be the same.
Lots of protections in the set so if there is no error codes
it could perhaps be the software.
Does the "heart beat indicator" blinks

[johns1mj]

Re: Sharp Aquos LC-52LE700UN No Sound No Picture

budm
I was using the tv chassis with an alligator clip. I was testing on dc with the measurement on auto. After reading your question I suppose it might have been ideal to have written down if it was measuring volts or millivolts. I will need to recheck the voltages in volts only.

Also, no there is no error code flashed. It will also time out like when no input is detected.

[johns1mj]

Re: Sharp Aquos LC-52LE700UN No Sound No Picture

Kilroys
Yes, the heart beat indicator blinks just over a second each time.

[budm]

Re: Sharp Aquos LC-52LE700UN No Sound No Picture

If you check the resistance between the GND pins of the connector and the chassis, it should all show <1 Ohm, if not you may have loose board mounting screws, or your alligator clips/wire has problem.

[johns1mj]

Re: Sharp Aquos LC-52LE700UN No Sound No Picture

I will recheck, possible clip problem. I have already checked the screws.

[johns1mj]

Re: Sharp Aquos LC-52LE700UN No Sound No Picture

pin 10 is 1.916 V when I adjust the meter.
it doesn't appear to be a ground issue.

[Kilroys]

Re: Sharp Aquos LC-52LE700UN No Sound No Picture

If it blinks it means that the mainboard is ok
You have tried “VOL (–)” and “INPUT” keys at a time,
and plug in the AC cord of the main unit to turn on the power.
Sure you got the right keys on the front ? Nothing.
Try this "channel DOWN and volume UP" and plug in the AC cord of the main unit to turn on the power.
Software problem ?