Sharp LC-60LE810UN Lamp error

[Eric D.]

Hello everyone!
I just acquired a Sharp Aquos for free.
When I plug it in, it will try to power on, but it fails.
The "error code" is 1 long flash, then 1 short flash, which suggests it is a lamp error code, according to the manuals.
I did a bit of research and did what I found could be the possible issues;
I removed the back panel, checked for continuity on both fuses where the power cable connects, and I get somewhere around 0.05. That should be good.
I also tested the leads going into the psu board from the wall connector; I get 120V.
I disconnected the cable from the main board to the psu board, it stops the blinking, but that obviously doesn't help (I just like to test things out in case there some weird shenanigans happening)
I looked around, some people suggest Vol- Ch+ and Power, others suggests Vol- Input and Power, others suggests Vol- Ch- and Power, other suggests Vol- and Input.... I tried all of these combinations, while the TV is on, and also before plugging it in, it still refuses to power on.
The woman who gave it to me says it was working fine the day before, then she came back from work, tried to power it on and it did that issue.
I'm trying to see if it can be a board issue as those are pretty easy to replace and find, compared to LEDs over here. I cannot seem to find the TK4459P anywhere, but I can find the TK4458P...
What could cause a TV to not want to go into the service mode?

[lotas]

Your TV is blocked due to excess errors, the eeprom 24C02 is full of the lamp error error, erase it on the programmer (fill in FF FF...) and your TV will turn on, but you will need to eliminate this error (repair the backlight).

[Superbee_dad]

Hello Sharp TV experts
Our Sharp LC-80LE642U displays one short one long flash error code which is a backlight error. I went into service mode and there were 8 lamp error counts recorded. I reset the count to 0 and did a reset. The last monitor error cause was 16 B00014639:12. 16 is the code for backlight error. I tried to power the tv up but went back into error mode.

> I checked voltages on the power supply board and they all check out .. including 3.28 volts at the error pin.
> There is power to the cpu and T-CONN and no faults found there. The cpu has a flashing green led.
> I have 110 volts DC at the LED driver MOSFET and 192 DC volts at the L1 LED string input connection. I found a spec for the LED input voltage of 215 volts.
> I removed the front panel and checked the LED strips with an LED backlight tester. I recorded 183 volts at each light strip and all LEDs light up bright. There are 15 rows with 21 to 24 LEDs per row.
> I checked voltages at the FETS on the return circuit. The voltages at the collector pin were 36 volts DC (+ or - 1/2 volt) at every FET. There are 15 FETS, one for each light string.
> This is where I found a peculiarity. I checked the voltage at the emitter of each FET and I also got 36 volts which I would expect … except for 4 FETS all beside each other had double or triple voltages. Three were 70 volts and one had 93 volts. I checked the gate voltages and they all are 5.5 volts except these 3 have 1.5 volts and is one has 18.4 volts. I removed the FETS from the board. There are 4 per heat sink so I removed 8.
> I checked the FETS with a multi meter following an online transistor test procedure. They all checked the same … okay.
Any ideas as to what is going on here and or what my next steps should be????

Thank you in advance. All expert opinions are immensely appreciated.

[Eric D.]

Hello Sharp TV experts
Our Sharp LC-80LE642U displays one short one long flash error code which is a backlight error. I went into service mode and there were 8 lamp error counts recorded. I reset the count to 0 and did a reset. The last monitor error cause was 16 B00014639:12. 16 is the code for backlight error. I tried to power the tv up but went back into error mode.

> I checked voltages on the power supply board and they all check out .. including 3.28 volts at the error pin.
> There is power to the cpu and T-CONN and no faults found there. The cpu has a flashing green led.
> I have 110 volts DC at the LED driver MOSFET and 192 DC volts at the L1 LED string input connection. I found a spec for the LED input voltage of 215 volts.
> I removed the front panel and checked the LED strips with an LED backlight tester. I recorded 183 volts at each light strip and all LEDs light up bright. There are 15 rows with 21 to 24 LEDs per row.
> I checked voltages at the FETS on the return circuit. The voltages at the collector pin were 36 volts DC (+ or - 1/2 volt) at every FET. There are 15 FETS, one for each light string.
> This is where I found a peculiarity. I checked the voltage at the emitter of each FET and I also got 36 volts which I would expect … except for 4 FETS all beside each other had double or triple voltages. Three were 70 volts and one had 93 volts. I checked the gate voltages and they all are 5.5 volts except these 3 have 1.5 volts and is one has 18.4 volts. I removed the FETS from the board. There are 4 per heat sink so I removed 8.
> I checked the FETS with a multi meter following an online transistor test procedure. They all checked the same … okay.
Any ideas as to what is going on here and or what my next steps should be????

Thank you in advance. All expert opinions are immensely appreciated.

Why are you using my post for your issues?

[Superbee_dad]

Sorry, it was my inexperience in using this forum. I was trying to make my first post and couldn’t find where to start. I was reading your post and only saw an area to post not realizing it was responding to yours. Then I couldn’t find out how to remove it.