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1 820-3115-b no backlight issue but has video
I have a MacBook Pro 820-3115-B.
There is no water damage and the customer brought it in for a thermal paste cleaning.
I changed the paste and put it all back together to find out they no longer have backlight…
The LDVS Cable has no damage nor the connector as I checked all the pins for damage….
I shined a light from the back and you see a image just no backlight…
Anyways, I am very little experienced in board level repairs and reading schematics but I did check the fuse… I thought it was that an I removed and ran a micro wire for testing and still no backlight..
However though the fuse reads when turned on and booting 11.7volts which I thought should be 12.5 volts
I also tested:
Capacitor C9710 1 Pin, the voltage is 5V
R9731 and R9715 to split voltage, the voltage measured is 2.9volts
Measure the resistor R9704 2 Pin, it has 3volts
I am not sure if U7901 IC Is blown for some odd reason. I take these MacBooks apart all the time and never had this issue….
Can someone guide me fixing this and what else to check….. I don’t know what else to do
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댓글 12개
@gns_solutions what voltage do you have on L9701 /D9701
oldturkey03 의
With no screen plugged in I tested them in dc mode and get 0 volts
Daniel Ringuette 의
Any other things I can try? I literally just took the board out and changed the paste and put it all back together and the backlight stopped working. It doesn’t make any sense
Daniel Ringuette 의
It may if you accidentally shortened something out on the connector. Have you checked if you get a backlight enable signal? Do you get the 5 volt to your driver from PP5V_S0_BKL? You obviously have the schematic so check the individual traces/components
oldturkey03 의
But how can I short the connector when the battery was unplugged . I plugged cable back in and it was fitting right then I plugged battery back in
Daniel Ringuette 의
댓글 7개 더보기