Random no startup.

[57chevy]

So this just started happening last week and today was the 3rd time it happened.  Just randomly the next day after a shutdown, my pc wouldn't start up.  Nothing at all on power button press.  Tried all the known troubleshooting tips and tricks. And the one thing that eventually worked was just unplugging the system, holding down the power button to drain any residual energy, and then trying to start up 30 minutes later. It's not a CMOS clear though.  I noticed my wireless earbuds charging light would turn on for a second or two after the unplug procedure.  I'd plug the the PSU back in and flip the power switch on the PSU and the earbuds would light up then turn off.  So it seems like power was going through the mobo and feeding the USB ports for a split second.  After doing the unplug procedure a couple of times, the system starts up no problems at all.  Is this signs of a motherboard failure in the near future? I haven't gotten any BSOD's in months so I don't know if this is a possible hardware failure. Gonna build a new system in the future but just need this bad boy to last a few more months to get the money.  Any help or insight would be greatly appreciated.  Thanks in advance. 

 

i7 7700

ASRock H270M Pro4 Micro ATX mobo (BIOS Fully updated)

Windows 10 64 bit

Seasonic 550 Watt 80+ Bronze

G.SKILL Ripjaws V Series 16GB (2 x 8GB) 288-Pin DDR4 SDRAM DDR4 2400

MSI Radeon RX 570 8GB GDDR5 Armor OC

 

Troubleshooting tips already performed:

Plugged directly into wall outlet

Clear CMOS (also replaced CMOS battery)

PSU swap (also did the paperclip trick to both PSU's to make sure they worked) 

Pulled a RAM stick

Disconnect GPU

 

Possible variable: My case is about 2 feet above a window air conditioner.  The previous owners decided an air conditioner near the floor was pure genius.  Anyway, the air blows under the case and into the room.  Could there be a moisture issue?