Sharp LC-50LB481U replaced bad LED's, still no backlight!
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Sharp LC-50LB481U replaced bad LED's, still no backlight!- RESOLVED
crwdns2934249:0crwdne2934249:0:
Okay I’m back with ANOTHER broken Sharp Roku TV. Model # LC-50LB481U. It had all the signs of a bad backlight- fully functional and you could see the picture with a flashlight. I took the entire TV apart, found the bad LEDs and replaced the strips. After putting it all back together there is still no back light. It seems as if the correct voltage is not being supplied. I can light the LEDs by using my LED tester at the respective harness connector.
I have tested the voltage at the LED harness connector and about 16 volts are being supplied where the LED tester would otherwise supply 59 to bring the LEDs on.
I pulled voltages at the connector from the main board to the power supply (pics below):
Back of Power board: A little blurry, I will take again and repost.
[image|2166251]
=== Update (07/26/2020) ===
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Better picture of back of power board :
[image|2166324]
=== Update (07/31/2020) ===
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Okay after replacement of the power supply board my TV is now operating normally. I am surprised that the TV required both LED strip AND Power Board replacement but it is what it is I suppose.
Sharp LC-50LB481U replaced bad LED's, still no backlight!
crwdns2934249:0crwdne2934249:0:
Okay I’m back with ANOTHER broken Sharp Roku TV. Model # LC-50LB481U. It had all the signs of a bad backlight- fully functional and you could see the picture with a flashlight. I took the entire TV apart, found the bad LEDs and replaced the strips. After putting it all back together there is still no back light. It seems as if the correct voltage is not being supplied. I can light the LEDs by using my LED tester at the respective harness connector.
I have tested the voltage at the LED harness connector and about 16 volts are being supplied where the LED tester would otherwise supply 59 to bring the LEDs on.
I pulled voltages at the connector from the main board to the power supply (pics below):
Back of Power board: A little blurry, I will take again and repost.
[image|2166251]
=== Update (07/26/2020) ===
+
Better picture of back of power board :
[image|2166324]
+
+
=== Update (07/31/2020) ===
+
+
Okay after replacement of the power supply board my TV is now operating normally. I am surprised that the TV required both LED strip AND Power Board replacement but it is what it is I suppose.
Sharp LC-50LB481U replaced bad LED's, still no backlight!
crwdns2934249:0crwdne2934249:0:
Okay I’m back with ANOTHER broken Sharp Roku TV. Model # LC-50LB481U. It had all the signs of a bad backlight- fully functional and you could see the picture with a flashlight. I took the entire TV apart, found the bad LEDs and replaced the strips. After putting it all back together there is still no back light. It seems as if the correct voltage is not being supplied. I can light the LEDs by using my LED tester at the respective harness connector.
I have tested the voltage at the LED harness connector and about 16 volts are being supplied where the LED tester would otherwise supply 59 to bring the LEDs on.
I pulled voltages at the connector from the main board to the power supply (pics below):
Sharp LC-50LB481U replaced bad LED's, still no backlight!
crwdns2934249:0crwdne2934249:0:
Okay I’m back with ANOTHER broken Sharp Roku TV. Model # LC-50LB481U. It had all the signs of a bad backlight- fully functional and you could see the picture with a flashlight. I took the entire TV apart, found the bad LEDs and replaced the strips. After putting it all back together there is still no back light. It seems as if the correct voltage is not being supplied. I can light the LEDs by using my LED tester at the respective harness connector.
I have tested the voltage at the LED harness connector and about 16 volts are being supplied where the LED tester would otherwise supply 59 to bring the LEDs on.
I pulled voltages at the connector from the main board to the power supply (pics below):
Sharp LC-50LB481U replaced bad LED's, still no backlight!
crwdns2934249:0crwdne2934249:0:
Okay I’m back with ANOTHER broken Sharp Roku TV. Model # LC-50LB481U. It had all the signs of a bad backlight- fully functional and you could see the picture with a flashlight. I took the entire TV apart, found the bad LEDs and replaced the strips. After putting it all back together there is still no back light. It seems as if the correct voltage is not being supplied. I can light the LEDs by using my LED tester at the respective harness connector.
I have tested the voltage at the LED harness connector and about 16 volts are being supplied where the LED tester would otherwise supply 59 to bring the LEDs on.
I pulled voltages at the connector from the main board to the power supply (pics below):
Sharp LC-50LB481U replaced bad LED's, still no backlight!
crwdns2934249:0crwdne2934249:0:
Okay I’m back with ANOTHER broken Sharp Roku TV. Model # LC-50LB481U. It had all the signs of a bad backlight- fully functional and you could see the picture with a flashlight. I took the entire TV apart, found the bad LEDs and replaced the strips. After putting it all back together there is still no back light. It seems as if the correct voltage is not being supplied. I can light the LEDs by using my LED tester at the respective harness connector.
I have tested the voltage at the LED harness connector and about 16 volts are being supplied where the LED tester would otherwise supply 59 to bring the LEDs on.
I pulled voltages at the connector from the main board to the power supply (pics below):
Sharp LC-50LB481U replaced bad LED's, still no backlight!
crwdns2934249:0crwdne2934249:0:
Okay I’m back with ANOTHER broken Sharp Roku TV. Model # LC-50LB481U. It had all the signs of a bad backlight- fully functional and you could see the picture with a flashlight. I took the entire TV apart, found the bad LEDs and replaced the strips. After putting it all back together there is still no back light. It seems as if the correct voltage is not being supplied. I can light the LEDs by using my LED tester at the respective harness connector.
I have tested the voltage at the LED harness connector and about 16 volts are being supplied where the LED tester would otherwise supply 59 to bring the LEDs on.
I pulled voltages at the connector from the main board to the power supply (pics below):
Top Row : 6.1V (fluctuating), 3.4V, GND, GND, 12.1V, 12.1V , 12.1V, 0
Bottom Row: 6.7V (fluctuating), 0V (no continuity), GND, GND, 12.1V, 12.1V , 12.1V, 0
As always, thanks for the help!