C84 lost phantom power

[Mewzishun]

The unit is a Rev 1.9.2

I have 2 of these C84's loaded in my rack. One of them lost phantom power. They've been racked since 2009. Although I'm not getting any phantom power, signal still passes using dynamic mics and anything else not requiring phantom.
I measured the output XLR pins and not getting anything, 0v. The known good C84 is showing 46v potential on the out pins.
The bad unit shows 47v up to the neg side of D19 then nothing after R71. With power off, R71 reads 149 ohms. I replaced C40 because I noticed 39ohms when measuring positive side of C40 to ground, but after replacing C40, it's still reading 39ohms. Something is definitely going on. I ordered a new MPSA06A and MPSA056A hoping this will fix the issue (should be here in a few days).

I don't understand why the phantom would just go out like that. Been using these for years now. Any thoughts or further suggestions?

[Mewzishun]

So I de-soldered Q12 (MPSA56A) from the board. Checked the MPSA56A base/collector junction and found the 39ohm short. Looks like that's the culprit. Without that Q12 installed, the base/collector junction on the PCB is in the Mohms. Gonna have to wait until I get the new part in before I know for sure, but I feel confident that PNP transistor is the issue. I'm going to leave Q11 alone.
Again, don't know how the part failed, but shit happens I guess-- parts fail from time to time.

[Mewzishun]

To conclude this thread...
Got the MPSA56A from Digikey yesterday. I soldered it into Q12 and resolved the issue. Phantom power has been restored.