Sharp LC-46LE830E Blinking light.

[Moreno83]

Hey guys ,

Got this tv that won't turn on. It's a led tv with leds on top side and bottom side.

When the mains is plugged in the V logo starts to blink immediately. Looks like a 1 blink that repeats forever.

I only measure 5v going to the mainboard. All other voltages on the connector from PS to mainboard are 0V.
Already replaced the mainboard , tv turned on for 2 / 3 seconds and is now also doing the same....

Any suggestions?

[ReeceyBurger123]

Re: Sharp LC-46LE830E Blinking light.

Backlights is one blink from what I remember, checked the Led drive and return voltage ?

[Moreno83]

Re: Sharp LC-46LE830E Blinking light.

Yes i was thinking the same. Where is the LED driver? The leds are connected directly to the PS

[ReeceyBurger123]

Re: Sharp LC-46LE830E Blinking light.

Lol the driver is built into the Psu buddy, the pins on that are labeled, does it state what the voltage should be per string ?

[Moreno83]

Re: Sharp LC-46LE830E Blinking light.

Sorry , new to these led tv's. Got a attic full with plasma's and 1 led tv

No they don't list the voltages. There is absolutely no voltages on that area except 5v on diode D7918 and a optocoupler.

[ReeceyBurger123]

Re: Sharp LC-46LE830E Blinking light.

Hmm seems like Psu fault too me, so nothing else apart from 5v on the motherboard connectors too ? Also what are the Pson and Blon signals doing when you try to power the set up ?

[Moreno83]

Re: Sharp LC-46LE830E Blinking light.

I got +/- 13V on the primary side of the optocouplers/diode's but only 5v on the secondary side. Looks like mainboard problem to me? New one does not work either so im confused.

[Moreno83]

Re: Sharp LC-46LE830E Blinking light.

Nothing , the led on front that looks like a V starts blinking immediately.

[Moreno83]

Re: Sharp LC-46LE830E Blinking light.

Ok , i found a shorted resistor on the power supply. Its R718. So looks like a bad power supply.

[Moreno83]

Re: Sharp LC-46LE830E Blinking light.

So after repairing some plasma tvs i decided to take another look at this LED tv.

I got another mainboard and now the tv somehow turns on. The white V led stays on.

One of the 4 led strips did not turn on as on the picture so i replaced that strip. Now all 4 strips light up as on the picture. The led strip on the picture comes out of a working led tv so im sure its ok.

The led on the mainboard next to the cpu is flashing.

The voltages on the connector going to the led strips are 88v , 143v , 88v , 143v , 57v , 143v and 88v. One or more leds are dead?


Any ideas?

[Moreno83]

Re: Sharp LC-46LE830E Blinking light.

On all sides the led strip turns on very faint. Some leds are completely off and the other ones are on. But very dimmed light.

On the new strip all leds are on but also dimmed. I think some leds are pulling the voltage down?

[mmartell]

Re: Sharp LC-46LE830E Blinking light.

How do you have seven measurements if there are only four strings ? Try measuring the value for each +/- pair.

Are you sure the resistor you replaced was shorted and not just a low-ohm value ?

[Moreno83]

Re: Sharp LC-46LE830E Blinking light.

Aah ofcourse! As i said , im new to these led tv's.
I just measured every wire lol. It would mean that 1 strip is not returning voltages or not correct voltages.

[mmartell]

Re: Sharp LC-46LE830E Blinking light.

Yes the leds should be uniform in brightness, might be indicative of failing leds.

[Moreno83]

Re: Sharp LC-46LE830E Blinking light.

Replaced all 4 strips , still same symptom. when i remove the small white cable going from T-con to the mainboard when the tv is on , the backlight comes on and then it goes into protection. ( Because it cant find the t-con ).

The LCD panel is disconnected from the tv at the moment. Tv must work without the panel right ?
It looks like a bad t-con....?