Hi,
I've been using this laptop for 7 years and then out of nowhere, I came home one day and it was turned off. I went to boot it back up and received a kernel panic right on the apple screen:
Safe mode:
https://www.dropbox.com/s/3tohvmelm7...20PM.jpeg?dl=0
Normal boot:
https://www.dropbox.com/s/8ei9e62wrv...20PM.jpeg?dl=0
After trying SMC resets, NVRAM resets I couldn't get it to boot. It would boot into recovery ok but it wouldn't reinstall el-capitan. Then, after the 9th or 10th reboot, the backlight started to become non-uniform along the bottom of the screen. Then the screen wouldn't turn on at all. Shining a light behind the apple logo shows that the screen is not displaying anything.
During this whole ordeal, the MBP would always chime everytime it panicked and continues to do so now that the screen is dead.
I've found the schematics: https://www.dropbox.com/s/6bjyw337t2...-2530.pdf?dl=0
and the board view: https://www.dropbox.com/s/rft4m8adl1...-2530.brd?dl=0
From poking around a little bit I've found that Q9806 has 0V at the drains despite having voltage at source and gate. I know fets aren't likely to give up the ghost unless provoked but I'm unsure what direction I should proceed in. I discovered the issue with Q9806 while measuring voltage on PPBUS_S0_LCDBKLT_PWR which was 0V.
The fuse (F9800) measures 12.6V on either side. The voltage divider (R9731 and R9715) receive 0V. Before replacing the fet I was going to try to find the issue that killed the fet in ther first place but with no voltage downstream of Q9806 I'm unsure how to proceed with my diagnosis.
I know everyone says that they didn't spill anything on it but I really didn't! I can post photos of the board if anyone is curious. Can anyone shed any light on this for me? Any components I should check and probe?
I've been using this laptop for 7 years and then out of nowhere, I came home one day and it was turned off. I went to boot it back up and received a kernel panic right on the apple screen:
Safe mode:
https://www.dropbox.com/s/3tohvmelm7...20PM.jpeg?dl=0
Normal boot:
https://www.dropbox.com/s/8ei9e62wrv...20PM.jpeg?dl=0
After trying SMC resets, NVRAM resets I couldn't get it to boot. It would boot into recovery ok but it wouldn't reinstall el-capitan. Then, after the 9th or 10th reboot, the backlight started to become non-uniform along the bottom of the screen. Then the screen wouldn't turn on at all. Shining a light behind the apple logo shows that the screen is not displaying anything.
During this whole ordeal, the MBP would always chime everytime it panicked and continues to do so now that the screen is dead.
I've found the schematics: https://www.dropbox.com/s/6bjyw337t2...-2530.pdf?dl=0
and the board view: https://www.dropbox.com/s/rft4m8adl1...-2530.brd?dl=0
From poking around a little bit I've found that Q9806 has 0V at the drains despite having voltage at source and gate. I know fets aren't likely to give up the ghost unless provoked but I'm unsure what direction I should proceed in. I discovered the issue with Q9806 while measuring voltage on PPBUS_S0_LCDBKLT_PWR which was 0V.
The fuse (F9800) measures 12.6V on either side. The voltage divider (R9731 and R9715) receive 0V. Before replacing the fet I was going to try to find the issue that killed the fet in ther first place but with no voltage downstream of Q9806 I'm unsure how to proceed with my diagnosis.
I know everyone says that they didn't spill anything on it but I really didn't! I can post photos of the board if anyone is curious. Can anyone shed any light on this for me? Any components I should check and probe?
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