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Old 08-20-2018, 02:27 PM   #1  
What is HD?

Join Date: Aug 2018
Posts: 1
Default Toshiba 50L2300U- LED s Go off

Toshiba 50L2300U- LED s Go off

My son has the above TV. When the TV turns on, the LEDs power up for a second and then turn off. You can see the picture using a flashlight and the sound is working. All the LEDs, in each of the groups, are working when you supply voltage.
My son replaced the power board himself as an attempt to repair the TV. It did not work. The LED power cord comes out of this board and feeds the power strip that all the LED banks are connected to.. I'm assuming all of the LED components are on this board, but not certain. I have not tested the components of the new board to check for proper voltages. I little confused as to why the new board did not remedy the situation.
I measured the voltages on the power board from the cable from the main logic board and got 12 volts where it was noted 12 volts should be, EXCEPT for the terminal "12v-LNB" which was 0.0 volts. On three other terminals marked:
BL on/off 3.2 v
Power TV 3.2 v
AC_detect 3.4 v
There was no noted values, so I don't know if these are correct.
On LED cable out to LEDs,:
L1+ 77.1
L1- 13.2
L2+ 77.2v
L2- 8.5 v
These voltages don't seem to agree with the voltages on the videos(Tampatec) I've been watching. According to him, you're looking for 100v. If you get 130 v, the back lights are bad. Mine are all lit. If 0.0v, a section of the LED driver section is bad. I don't know if these voltages vary from manufacturer to manufacturer. My electronic knowledge is limited so any guidance is appreciated. I'm waiting for a capacitor reading meter(Excelvan M6013 Digital Auto Ranging Capacitance Meter Capacitor Tester Professional 0.01pF to 470000uF) to check out individual components.
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