PS4 Pro beeps, shows blue light for a second, and doesn't boot.

Previously working PS4 Pro does not turn on after disassembling and cleaning. It beeps, a blue light shows on the console for a split second, and then nothing happens.

Background:

Got a new-to-me PS4 Pro and it was running loud, so I decided to take it to the computer shop I work at and do some cleaning on it. I followed this guide on PS4 Pro teardown and removed both the fan and heat sink to brush and blow them both out sufficiently. The heat sink was about 50% clogged with dust, so it was no wonder the thing was running so hot and loud. So while I was at it, I figured I'd go ahead and replace the thermal paste. After putting it back together and bringing it home, I experienced the problem listed above.

I tried a different power cable that I knew worked (from my PS4), I tried different outlets, etc. So I brought it back to work and plugged it up to test it here, and it was still doing the same thing. Beeps, blue light comes on for a second, and then nothing happens.

Things I've tried:

1. I've obviously tried unplugging it for 30 seconds, draining residual power, and trying the power button again.

2. I've tried holding down the power button until a second beep can be heard in order to rebuild the database- I held it down for 60 seconds and never heard a second beep.

3. I've re-opened it to ensure that all Wi-Fi antennae and ribbon cables are connected. I've ensured that the fan and power supply are both connected. I've unplugged and reconnected all of these components to ensure that they're making firm connections.

4. I've unscrewed the screws on the back of the APU to various levels of tightness as some users have suggested.

5. I have tried knocking it and bumping it as some have suggested.

The only thing I could think would have happened would have been that I damaged the PSU in some way. The most likely way it would have happened is when I was removing the PSU. I lifted it, but it wouldn't come out easily so I had to somewhat force it. I didn't do damage to or unplug either end of the PSU connector when this happened, but the metal clips that hold it in place got a little bent. I bent them back into place more or less, but they still look wonky when the PSU is out.

So unless correct contact by those clips is required for booting, then I don't know what could be the issue. The only other thing I could thing of is maybe I damaged the PSU when I was brushing out dust, but I was pretty careful and I'd like to think a small paintbrush wouldn't be enough to destroy a PSU. But if a component is bad, I'm betting it's the PSU in this case since the APU fix isn't working. Just looking for advice, suggestions, or confirmation that I need to replace the PSU. Thanks.