Re: 820-3330-B A1286 Image, No Backlight

photos...

Re: 820-3330-B A1286 Image, No Backlight

Update, added some solder to the pads where the missing component was, took R7408 from 820-2530, soldered it to the pads on my 820-3330-B, it isn't pretty, but to my amazement, I now have backlight, so from what I can tell Q9707 is fine besides having that cosmetic damage. Now only time will tell if it'll last.

Thank you for your help mon2!

Re: 820-3330-B A1286 Image, No Backlight

I haven't had a chance to get those measurements, but I looked back at the board today, and comparing it to a 2011 2.4 i7 board (820-2915) I noticed a component next to Q9707 was actually completely missing, and according to this diagram, it looks like that is a point which LCDBKLT_EN_DIV goes through to LCDBKLT_EN_L. I'm going to try to replace the cap/resistor, whatever it may be and see if that fixes it. My donor 820-2530 has two of these:

147K
1%
1/16W MF-LF
402

Will update....

Re: 820-3330-B A1286 Image, No Backlight

I unfortunately do not know if it was nicked before or after, all I know is it is currently nicked. It looks to be linked to the lcd backlight in some ways. From what I can tell it looks like it controls the enabling and disabling of the backlight based on the trace/pin names....

Hey guys,

Looking for a bit of advice here, I'm very new board repair specifically. Randomly the backlight stopped working on my Mid 2012 15" MBP 2.3 Unibody. Had left it for a few hours and came back to the backlight no longer working. To note, I keep the bottom panel unscrewed due to the ram slot issues, so it is a very small possibility something could've gotten nicked. I measured some voltages, so here's what I got:

10.71V on both sides of F9700 (PPBUS_G3H) & (PPBUS_S0_LCDBKLT_FUSED)
Continuity to R9788 & C9782
Q9707 only thing that...

Re: New Members - please post your introductions here

Hi! New here. Been working on electronics professionally since 2018. Looking to access some posts on board repair for my 820-3330 Mid 2012 15" MBP