A2338 820-02020-A 5V, no screen, unable to revive/restore

[yheriatovych]

https://repair.wiki/w/MacBook_Pro_A2...w_at_5V_repair
This resource suggests checking caps around WiFi IC (UL000).
There are two that look suspicious.
Will verify with the power injected, but need some time to make an adapter to use multimeter probes for that.

BTW: What is the best way to clean that epoxy (or whatever that is) around WiFi ic?

[mon2]

Very nice finds on the Rossmann link and now these parts. Personally, would use low heat @ 100C + low air pressure and hover over this area. The heat should case this epoxy to become soft or brittle enough to break off and then grant you access to the SMD pads. Voltage inject + IPA over these parts will confirm if they are the root cause. Do wear a mask as we do not know about what the fumes may lead to in the future.

[yheriatovych]

Update on the case:
Using power injection (1V, 5A) and IPA, I verified that the head was produced from that exact area with the two caps (CL053 and CL002) near the WiFi chip.

I desoldered both and they both were shorting. With those removed the short on PP3V3_S2 rail was gone.
The hardest part was to get through the epoxy/glue around the WiFi chip.

Attaching USB-C power to the motherboard alone switched to 20V (it did not before). After putting the motherboard in the laptop and attaching all the peripherals the laptop turned on, booted and everything is working as expected (including screen, wifi, battery, and fan).

So the case can be considered solved. I will still not fully assemble the laptop as I will buy similar caps and put them back where the bad ones were. Unfortunately, I ripped off one of the pads under the CL053, but it's ok as I can solder it with the CL002, as they are just in parallel.

Thanks mon2 for the help and guidance during this repair.