Hi. My sister gave me this Insignia 42" NS-L42Q-10A flat screen. At first, I thought it'd be an easy fix. It doesn't power on at all. I looked an the main board, and capacitor C743 was blown. I replaced it but still nothing. I have attached some pictures and the service manual. On the power board, there's a connector that goes to the main board. It's CN903. I've tested the voltages with the TV off and turned on. This is what they read:
CN903 ON OFF
ON/OFF 0.5mv 0.5mv
PDIM -0.2mv -0.2mv
+12V 14mv 18.6mv
+12V 14.1mv 17.8mv
Gnd
Gnd
Gnd
24V 12.1mv 11.4mv
24V 12.1mv 11.5mv
PS_ON 125.3mv 125.4mv
5V 5V 5V
5V 5V 5V
I also tried doing some tests on what I think are the voltage regulators. With the TV turned off, I tested the resistance between pin 3 and ground and then the long tab at the top of the voltage regulators and ground. This is what I get:
Pin 3 - Gnd Long Tab - Gnd
U709 654 ohm 1.236Kohm
U708 4.6Mohm 0.654Kohm
U703 1.65Kohm 153.1ohm
U702 0.4ohm 0.3ohm
U708 on pin 3 just kept climbing. Also, U703 on pin 3 kept on climbing too. I just didn't hold it there for very long. Shouldn't U702 be reading higher? Does this mean there's a short some wheres? And is U708 so high because it's bad?
Also, I pulled off this little cover and was looking at some of the stuff under it and it looks like some of the surface mount stuff might of leaked. C401 and C451.
My sister, when she gave it to me, she said it had a blue line going all the way down the middle of the screen and someone told her it was dead pixels. Didn't really make sense to me why dead pixels would die in a straight line and be blue but I guess my sister says the guy claims to be a professional with these TVs. I was thinking maybe those two caps, C401 and C451 might of caused the blue line?
She also said she had the XBOX 360 hooked up to the TV via HDMI and all of the sudden the TV just shut off and the 360 started making a weird buzzing noise. She took the 360 back to the store, they tested it and said it was shot and they replaced it for her. It wasn't storming out or any thing and nothing else was effected. I believe the 360 and TV where on surge protectors. Could anyone please help me figure out how to fix this TV? I'd greatly appreciate it.
CN903 ON OFF
ON/OFF 0.5mv 0.5mv
PDIM -0.2mv -0.2mv
+12V 14mv 18.6mv
+12V 14.1mv 17.8mv
Gnd
Gnd
Gnd
24V 12.1mv 11.4mv
24V 12.1mv 11.5mv
PS_ON 125.3mv 125.4mv
5V 5V 5V
5V 5V 5V
I also tried doing some tests on what I think are the voltage regulators. With the TV turned off, I tested the resistance between pin 3 and ground and then the long tab at the top of the voltage regulators and ground. This is what I get:
Pin 3 - Gnd Long Tab - Gnd
U709 654 ohm 1.236Kohm
U708 4.6Mohm 0.654Kohm
U703 1.65Kohm 153.1ohm
U702 0.4ohm 0.3ohm
U708 on pin 3 just kept climbing. Also, U703 on pin 3 kept on climbing too. I just didn't hold it there for very long. Shouldn't U702 be reading higher? Does this mean there's a short some wheres? And is U708 so high because it's bad?
Also, I pulled off this little cover and was looking at some of the stuff under it and it looks like some of the surface mount stuff might of leaked. C401 and C451.
My sister, when she gave it to me, she said it had a blue line going all the way down the middle of the screen and someone told her it was dead pixels. Didn't really make sense to me why dead pixels would die in a straight line and be blue but I guess my sister says the guy claims to be a professional with these TVs. I was thinking maybe those two caps, C401 and C451 might of caused the blue line?
She also said she had the XBOX 360 hooked up to the TV via HDMI and all of the sudden the TV just shut off and the 360 started making a weird buzzing noise. She took the 360 back to the store, they tested it and said it was shot and they replaced it for her. It wasn't storming out or any thing and nothing else was effected. I believe the 360 and TV where on surge protectors. Could anyone please help me figure out how to fix this TV? I'd greatly appreciate it.
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