M1 MacBook Pro 2021 A2485 - No backlight display

[rcanpolat]

Hi all,

I recently got my hands on an M1 MacBook Pro (2021, A2485) that I suspect suffered some liquid damage. I have a hot air station and the basic tools to work on the board, but I’m new to SMD repair and would love some guidance before diving in.

Here’s what I’ve observed so far:

• When I power it on, I hear the MacBook chime and, with a flashlight, I can see the Apple logo on the screen. However, it never completes the boot and eventually powers off. My plan is to try to get the display fully working first, then tackle the boot issue.
• I did some basic resistor checks on the board around the display area and they seem OK.
• I noticed one component (CP803 – 33µF 20% 16V TANT CASE-T POLY-TANT, drawing number 820-02100-08) looked damaged, so I desoldered it.

I’m considering replacing it with this part from Mouser: T521T336M016ATE050. Is this an acceptable replacement? I’ve measured it with calipers and it seems to match the physical size, but I don’t have a donor board to confirm.

https://eu.mouser.com/ProductDetail/...OHVVSwYA%3D%3D

Some additional info:

• Pre- and post-desoldering that component, measuring between ground and CP834 (XWP801) gives ~7.5V, not the expected 15V.
• My multimeter is an RS PRO RS-12, so no capacitance testing is available. I’m open to buying a capacitance meter if that’s necessary for testing/desoldering the caps.

I’d really appreciate any tips & guidance for a first-timer on what to do next. I have successfully repaired some other (non apple devices) where i could clearly see damaged components but this Macbook is turning into a hard one for me.

Thanks in advance!