820-3437, Won't Detect SSD, Liquid

[SMMRepair]

Dealing with a board that had liquid-damage, but was cleaned very, very well. Hard to tell where all the liquid intruded, but nothing visible damaged/corroded anymore. The only issue with the board (so far) is that it won't detect an SSD.

1. SSD_PWR_EN, PP3v3_s0sw_ssd_flt both present
2. No caps/resistors missing from area or data lines; checked entire board well, no damaged or missing components (this has always been the cause of no-SSD-detect on previous boards, so I looked well)
3. R3700/10 measure out fine

Before I go through and compare all diode measurements and check each data line, I wanted to check to see if there's anything else I should check/do beforehand. Any help appreciated as always, thanks!

 

[aprendiz]

EFI lock? can you boot from external drive???

 

[SMMRepair]

Hey Aprendiz, no EFI lock. PRAM resets fine. Boots to USB drive fine as well. No storage/SSD detected in system preferences or system profiler, etc. SSD also does not seem to get as warm as one normally does (it's warm, but seemingly from proximity to CPU).

 

[dukefawks]

Just to be sure, did you try a known good SSD? Next would be some diode mode readings on the connector and check the traces to the PCIE caps.

 

[SMMRepair]

Hey Duke, thanks. Yeah I tried 3 SSDs just to be safe. I'll get into diode readings tomorrow and will post those; will also check all my continuity on those caps. Will post back tomorrow!