Sharp LC-40LE810UN question

[budm]

Re: Sharp LC-40LE810UN question

As you can see, there are two transformers that supply the power to the LED strings, one per string, It has to be some thing in that LED drive power supply whcih is common to both strings. Bothe transfoemrs primary are connected in series and driven by the the same set of MSOFETs Q7601A/7601A setup as a half bridge drive. Which IC that you blow when you short the Opto? U????

[tibimakai]

Re: Sharp LC-40LE810UN question

I will give it a try. Thank you.
I guess it would be very good if we could start the inverter to make sure that it starts, but I don't know how come last time blew that IC.
You are sure that that's the opto for that?

[olegi]

Re: Sharp LC-40LE810UN question

Last week I had same model 60" (two long 5 short). SHARP 60" has full 4 LED strings .Problem was Only 1 single led of one string. Tv was very hard to disassemble , because of the size (very fragile to ) Hope this helps.
Backlight diodes http://www.sharpsma.com/lighting/led...es/GM2BB45BMAC

[tibimakai]

Re: Sharp LC-40LE810UN question

What else can I try?
I'm becoming frustrated, I have three monitors(2 small TVs) and three TVs that I'm having a hard time fixing them.
42" LG shorted PS, 42" Philips 7422D/37 no power, 24" Asus w/blown components, 22" LG M2262, 22" Samsung w/mystery PWM chip.

[budm]

Re: Sharp LC-40LE810UN question

I do not think it will be bad LED assemblies since there are at least two strings of LED and I doubt that both of them went bad at the same time. Iworked on LED backlights monitor last week and one of the pin on the connector for one of the sting was bent, the other string still lights up.

[tibimakai]

Re: Sharp LC-40LE810UN question

I have tried disconnecting each cable at a time from the T-con, with no change.
At this time I'm suspecting the LEDs in the panel.
I will take it apart.
Replacement power supply/inverter board didn't change anything(hopefully it was a good board from partstore), removing the EEPROM didn't change anything, there is only the LCD panel left.

[Alohamora]

Re: Sharp LC-40LE810UN question

Do you mean on the bezel? If yes ,then yes the same as before two long and five short blinks.
Should I take the LCD apart to check for bad LED?

No. 2 long & 5 short is 12V panel power, i.e. t-con problem or LCD panel short.
Disconnect both of the flat cables between the t-con and the panel, then power it on. What happens?

[tibimakai]

Re: Sharp LC-40LE810UN question

Do you mean on the bezel? If yes ,then yes the same as before two long and five short blinks.
Should I take the LCD apart to check for bad LED?

[tibimakai]

Re: Sharp LC-40LE810UN question

No. I measure 0.009V at the LEDs. At one connector the voltages are positive and at the other are negative. I'm affraid to toch again the opto. It will take more then two weeks to get new ICs.

[tom66]

Re: Sharp LC-40LE810UN question

any LED-ON signal or similar coming up?

[tibimakai]

Re: Sharp LC-40LE810UN question

Ok, I'm back with the error code blinking.
I had to replace the 3BS03LJG IC, I was lucky to have an extra one.

[tibimakai]

Re: Sharp LC-40LE810UN question

I have placed the DMM probes to the LED DRV. pins and I have started it up, then I have touched the two pins on that opto and for a second the light bulb(I have a short circuit tester with a 100W bulb) turned on and then off. Then the V Led did not tun on. All this time the voltage haven't changed, stayed at 0.009V.

[olegi]

Re: Sharp LC-40LE810UN question

What did you do exactly?

[tibimakai]

Re: Sharp LC-40LE810UN question

I couldn't find the diagram. The SM from elektrotanya doesn't show the power supply.
Now I have bigger issues, I have to find the bad component.

Bud, could you please look at the Samsung 2333 please?

[budm]

Re: Sharp LC-40LE810UN question

That opto may be for the voltage regulator feedback, need to find out if that is the correct opto. Need to find the diagram for this board.

[tibimakai]

Re: Sharp LC-40LE810UN question

I have measured the voltages and there is not much change. On the upper connector I had +0.009V on both pins and on the bottom connector I had -0.009V on both connectors.
I have tried the replacement board also, and it measured exactly the same.
When I shorted the opto, the bulb on the short tester outlet lit up and since then I don't have any voltages and no LED light on the front of the TV.
The only voltage that I have is the 170V on the main caps.

[olegi]

Re: Sharp LC-40LE810UN question

Ok. All cables has to be attached (specially those for LEDs led_drv1 and led_drv2) Power up tv,wait ~ 10 sec. Voltmeter has to be attached (neg to ground) ,with positive probe you have to check each pin on LED_DRV (1 an2 , +and -).DC voltage should be ~ +95v -95v depend of different factors .If you have ~0v,then you have to manually turn ON backlight inverter .By looking on yours particular board optocoupler PC 7702,turn backlight On.You have to short with INSULATED scrwdriver ,PRIMARY side of optocoupler as is shown on the picture (don`t short any of the other optocouplers,do not mesure primary side circuit HI VOLTAGE HIGN FREQ),then measure readings.Post result.

[tibimakai]

Re: Sharp LC-40LE810UN question

I have measured the LED voltage, early before I left to work and measured from the secondary ground and I'm getting on all the pins 0.0019V.
From primary ground I'm getting 28.6-28.8V.
But I think that I have to measure from the secondary.
I have tried even without the LEDs and I'm getting the same voltage.
When I will be home, I will try with the replacement board, to see if I'm getting the same voltage.
I guess these voltages should be DC voltages, since the LEDs are diodes.

[olegi]

Re: Sharp LC-40LE810UN question

I read this guide 2 seconds to black
(https://www.badcaps.net/forum/showthread.php?t=10419) and your tv it is bit differant

[olegi]

Re: Sharp LC-40LE810UN question

This Tv, when you press power on button it is dark ~ 5sec then lit up.