Sharp LC-70SQ15U - Problem disguised as a 3-1 Blink Code ?

[SpeedAddiction]

Hi All -

Trying to get things working again after a very inconsiderate lightning strike. Immediately after I started getting a 3-1 blink code on the Sharp (it was off during the strike) which is a Main Board communication error. I ordered another main board before starting to diagnose since the lightning killed everything else hooked into the TV.

After extensive BadCaps and internet tutelage this is what I have...

Sharp 3-1 blink code :
"Initial communication from the main CPU is not received. (Request for the monitor model No. is not received after canceling the reset.) → Communication line error or main CPU start-up failure."

(All tests run on both Main Boards just in case)

Unplug > Hold Vol-/Input > Plugin : Same 3-1 blink code
Unplug > Hold Pwr > Plugin : Constant fast blinking
Unplug > Hold Vol+/Ch- > Plugin : No blink code/no backlight/no sound/no picture(flashlight)

New Main Board : Same 3-1 blink code
Unplugged Pwr/LVDS from TCon : Get 2-5 blink code
Only Flex cables from TCon to Panel unplugged : Backlight and sound working
Only Left side(looking at back) Flex cables unplugged : Same 3-1
Only Right side(looking at back) Flex cables unplugged : TV springs to life on the side still plugged into TCon. White on other half.

I've read this normally leads to a TCon or Panel issue (most likely panel) but why do I keep getting a 3-1 blink code instead of a 1-1 or 2-5 blink code?

What am I missing on this?

[budwich]

Re: Sharp LC-70SQ15U - Problem disguised as a 3-1 Blink Code ?

when you unplug the "flex cable" which I assume are the small cables at each corner of the panel, you need to have ALL the tcon cables connected. If things happen (ie picture), then you can go from there.

[SpeedAddiction]

Re: Sharp LC-70SQ15U - Problem disguised as a 3-1 Blink Code ?

So with everything plugged in and only the flex cable on the right side corner(facing back of tv) unplugged...

We have a result! Not my preferred one if I'm honest, but a result. The TV shone in all it's brilliance... on one side as it trailed to a glow on the other...

So by other threads it looks like I only have one course of action. The tabs/boards on the trouble side have gotsta go, don't they?

[budwich]

Re: Sharp LC-70SQ15U - Problem disguised as a 3-1 Blink Code ?

So... now you notice that you no longer have any flashing codes.... AND you have a picture. Good / bad :-) Of course, this means that you have a tab issue on the dark side of the set (ie. the side that is not connected to get a picture). Removing the tabs will get you a clear and "back to normal" picture. The set will operate OK in this mode.
There are no other solutions that have been found to get around the problem. When you are looking at the tabs, it is likely that you will notice ones that are "stressed" and likely the cause for the problem.... but they have to be removed to stop them interfering with the panel drivers of the other side.

[SpeedAddiction]

Re: Sharp LC-70SQ15U - Problem disguised as a 3-1 Blink Code ?

Perfect. Thanks for the help and confirming my fears! Time to mentally prepare myself to go operate on the TV later.

Still a little curious why it decided to throw a Main Board communication error. The world may never know...

[budwich]

Re: Sharp LC-70SQ15U - Problem disguised as a 3-1 Blink Code ?

the faulty drivers put stress on the system and the error code system isn't the most "rocket science" developed by the manufacturer.... :-)
good luck... its a big tv so make sure your setup for taking apart the frame and getting at the side is good so that the panel stays relatively flat with no flex.

[SpeedAddiction]

Re: Sharp LC-70SQ15U - Problem disguised as a 3-1 Blink Code ?

Just wanted to disclose that the surgery was a success and the patient is back in action.

Thanks for the help Budwich!

[budwich]

Re: Sharp LC-70SQ15U - Problem disguised as a 3-1 Blink Code ?

great.... another one DOESN'T bite the curb!

[RJARRRPCGP]

Re: Sharp LC-70SQ15U - Problem disguised as a 3-1 Blink Code ?

Looked like failed LEDs...

[miataz]

Re: Sharp LC-70SQ15U - Problem disguised as a 3-1 Blink Code ?

Mine was a 3-2 blink, caused by excessive current draw on the 3.3V supply provided by CH2 of U6802, a Rohm BD81002, 96-pin flat pack 6-channel supply & VCOM IC on the T-con board.
I pulled the right-side tabs on my LC-70SQ15U after troubleshooting to the corner cable and reading freakaftr8's thread on the vizio 70" failures. (before, with bottom right cable disconnected: thumb2) The bottom right drive chip was bad, judging from appearance of the chips on the ribbon cables (thumb4) After picture was restored (thumb3), I re-attached the right-side bezel and began re-assembling the tv. Maybe I got one of the plastic moldings that support the side of the LCD in wrong, but the next morning, while watching, a 5-pixel high horizontal dark line appeared in the middle of the screen, followed a few minutes later by another, about 16 pixels below it. I loosened the side bezel screw in the middle, but the lines persist. (thumb1)

Any guesses?

Also, in retrospect:
I noticed when I was troubleshooting - before I got the tip on Freakaftr8's thread - that the 12V supply current to and from the T-con board was not balanced: supply current was about 1.8A; return current was only about .5A, measured with my Extech AC/DC Mini Clamp Meter, which would easily fit around the outrigger boards which feed the drive chips. Has anyone tried using a clamp meter like this on the outrigger boards to identify the specific chip and just cut out that ribbon and chip instead of removing all 5, with no way to go back if a failure on the other side occurs?

[budwich]

Re: Sharp LC-70SQ15U - Problem disguised as a 3-1 Blink Code ?

I don't think leaving the "bad side" tab bonds in place, at least any you "think" are still good is an option as I think freakaftr8 / others tried similar "efforts" before arriving at the "current solution".

As for you issue, I would check the removal areas to ensure that they are clean PLUS ensure that any cabling the you played with along the way has been correctly restored.... use your glasses ... :-) as some people have been "less than good" at reclamping cables / connectors properly... even though they "look good".