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Dan
Dan, Master Tech and Repair Facility Trainer
Category: TV
Satisfied Customers: 7203
Experience:  USAF trained; A.A.S Electronics; A.A.S. Education; Currently teaching advanced troubleshooting and repair for the DoD.
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Same issue power board didn't fix it. What's next?

This answer was rated:

Same issue power board didn't fix it. What's next?

Welcome to the site! I'm Dan, and I'd be happy to help. What's the full model number of the TV? What's the part number on the board you installed?

Dan

Customer: replied 1 month ago.
lc-70ud1u
RDENCA471WJQZI have tried 2 power boards, 1 main board, and 1 frc+drc board
Customer: replied 1 month ago.
When I disconnect the cable going to the power board from the frc+drc board the flash pattern doesn't occur but obviously the tv still doesn't work
Customer: replied 1 month ago.
BTW the flash pattern is 2 power 5 red

2 long, 5 short? Do you have a meter to measure voltages? Where did you get the boards from, and do you have a service manual?

Sorry, a lot of questions. Just need to make sure I'm understanding your issue.

Customer: replied 1 month ago.
It flashes 2 blue and five red. I got the boards from different places. I have measured the 13v supply and when the one board is disconnected it reads 13v when it's connected it reads 12.6v. I do not have a service manual

OK, thanks for that info.

On this chassis, that 2/5 error code you're seeing is almost always caused by a defective power supply board, or a failed display panel. Sometimes it's the LED driver board, and in very rare cases, I've seen the main board or the FRC cause it, but only once or twice.

Since you've already replaced the power supply, main and FRC, you could try the LED driver (>>link<<). Considering how much work you've already put into this fix, I would go ahead and do the LED driver. It's about $50, and the only other possibility (that you haven't already tried) is the display panel itself.

The panel would be pretty bad news, sorry to say. Replacing the panel is possible but it wouldn't be cost effective. $1,000+ just for the part.

I hope that answers your question. Let me know if I can do anything else, and please remember to rate the service I've provided. I hope it was excellent!

Dan

Customer: replied 1 month ago.
Is there a way to prove a bad panel? I'm struggling with this being the issue because when I disconnect the frc board from power the TV doesn't give the error but disconnecting the t-con board from frc, which is between the panel and the frc still gives the error. When I disconnect the led driver from the power supply makes no difference, still get the error. Please advise.

There is not a reliable test to prove a bad panel in this case. I understand it being difficult to accept, particularly without black and white verification.

The FRC test you performed was a good idea, but really doesn't help since you've already replaced the FRC. And, that type of test isn't as good as it used to be on older TVs or other electronics. The micros on these modern TVs will trip and act funny when something is disconnected from the system, so when you think you've found the problem, you haven't... it's just a symptom of the item you disconnected being out of the loop.

I'm not normally in the business of second-guessing whether or not replacement boards are "also bad" or I'd go crazy. Not that it's impossible, of course. It's just not typically advised. You could always try another FRC if you really think that's the problem.

I would roll with the LED driver (regardless of whether or not it changed when disconnected) and hope that's the issue. Otherwise, I'm afraid the panel is your problem.

Customer: replied 1 month ago.
you would just do the led driver and not the t-con?

The symptoms aren't really lining up with a typical Tcon failure, and Sharp is really picky about the Tcon & panel addresses so a lot of times it's not really a replaceable part (without also replacing the panel). I suppose it's possible.

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