Sharp LC-70LE745U no backligth no image

[hmendez86]

I got this led sharp 70' inch.....i turn on the tv and i did get the geen ligth pulse on the main board and itblinks and 12v on t-con....on the power supply side am getting 83.4v for leds output....i was thinking that regulator on the power supply but neither too is working fine getting 13.2v

[hmendez86]

Re: Sharp LC-70LE745U no backligth no image







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[nomoresonys]

Re: Sharp LC-70LE745U no backligth no image

Try test #3 below, try to do it just as instructed with the pins numbered and labeled.

[hmendez86]

Re: Sharp LC-70LE745U no backligth no image

I change the power supply.....change power supply cables to main board....and still nothin.....i removed the bar leds and they all work well with my led tester...

[hmendez86]

Re: Sharp LC-70LE745U no backligth no image

Any more suggestions

[budm]

Re: Sharp LC-70LE745U no backligth no image

Read post #3 again and follow the request.

[hmendez86]

Re: Sharp LC-70LE745U no backligth no image

1.pnl-12v
3.gnd-0.0
5.ur-13.2v
7.ur-13.2v
9.gnd-0.0
11.gnd-0.0
13.ac-det-3.3v
15.bus-5v
17.pwm1-0.0v
19.dimmer-0.0v
21.ofl-0.0v
23.pwm2-0.0v
*
2.pnl-12v
4.gnd-0.0
6.ur-13.2v
8.ur-13.2v
10.gnd.-0.0v
12.gnd-0.0v
14.ps_on-3.0v
16pnl-pow-3.3v
18.nc-33v
20.nc-3.3v
22.error-0.0
24.stb-3.3

[hmendez86]

Re: Sharp LC-70LE745U no backligth no image

I already add another set of leds and still not turning on

[nomoresonys]

Re: Sharp LC-70LE745U no backligth no image

"18.nc-33v
20.nc-3.3v" Something wrong there, nc stands for not connected, so check if they are connected.

[budwich]

Re: Sharp LC-70LE745U no backligth no image

try the force on sequence?

[hmendez86]

Re: Sharp LC-70LE745U no backligth no image

Yea i know something is wrong at NC should be not connection and am reading 3.3v on #18, #20 both 3.3v

[hmendez86]

Re: Sharp LC-70LE745U no backligth no image

How do mean to force the sequence ....i try the vol- and chan+ to force

[budwich]

Re: Sharp LC-70LE745U no backligth no image

Yea i know something is wrong at NC should be not connection and am reading 3.3v on #18, #20 both 3.3v

that's "better" than what you wrote previously... 33v on pin 18 :-)
perhaps the NC means that there is no circuit connected at the other end. Check where those go at the other end.... likely no where.

the force on sequence involves holding down some buttons as you indicate but also plugging in power at the same time.

You are sure that you are not getting any flash sequence on the front panel?

[hmendez86]

Re: Sharp LC-70LE745U no backligth no image

The first sequence was one slow one fast means to led problem...but i did force to those buttons and work but no led goes on only main pulse green ligth and t con 12v.

[nomoresonys]

Re: Sharp LC-70LE745U no backligth no image

17.pwm1-0.0v
19.dimmer-0.0v
21.ofl-0.0v
23.pwm2-0.0v Looks like problem there if those are with power on, if ofl is same as bl-on then it looks like the mainboard isn't sending the on signal??

[hmendez86]

Re: Sharp LC-70LE745U no backligth no image

On pin 21-ofl am now getting 3.0v

[nomoresonys]

Re: Sharp LC-70LE745U no backligth no image

Looks better, what about the other 3?

[budwich]

Re: Sharp LC-70LE745U no backligth no image

The first sequence was one slow one fast means to led problem...but i did force to those buttons and work but no led goes on only main pulse green ligth and t con 12v.

sorry, but not quite understanding.
are you getting a "flashing code" from the front panel without doing any "force on"..... OR that was the flash code before you replaced the leds?

[hmendez86]

Re: Sharp LC-70LE745U no backligth no image

No, when i replce the main board for the first time i was getting one slow and one fast..so i did the force button and then the blinking ligth was gone and the main start to function because the green ligth on main started to pulse and t con had 12v on connector. So when all started to work there was no back ligth so i was thinking it was led, i did buy the whole set of led and is doing the same thing so now i am ????

[hmendez86]

Re: Sharp LC-70LE745U no backligth no image

The other 3 pins 17,19,23 they are at 0.0v