PC freezes randomly and does not post afterwards

Hello all! Can someone please help me?

The problem I've been having for the past few days is basically summarized in the title. It doesn't seem to matter what I'm doing on the PC (either writing a document or playing videogames), it freezes for an undefinite amount of time. I then have to manually turn off or reset the computer, only for it to not boot up. Sometimes I get to the splash screen before freezing again, but most often the monitor doesn't even get a signal. Only the fans spin in these moments.

I'm pretty sure it's a hardware problem, because it happens with both the Linux and the Windows partition. I think it's a problem with my motherboard, but I'm not sure.

I moved the RAM stick to all other slots to no avail. I tried to boot up with no peripherals whatsoever (with the exception of the monitor and keyboard), but thst didn't work either. I cleared CMOS a bunch of times, and even removed the battery twice, and that seems to mitigate the problem (the PC generally boots up afterwards), but it doesn't fix it completely.

I have not tried with a different motherboard, CPU, RAM or PSU because I don't have access to extra components.

Here are my specs (both OS's are fully up-to-date):

• CPU: AMD Ryzen 1600AF (using the stock cooler);
• Motherboard: Gigabyte AB350-M DS3H-V2;
• GPU: AMD Radeon R5 230;
• RAM: Crucial Ballistic 16GB at 2666MHZ (single channel and XMP is disabled);
• SSD: Adata Swordfish 250GB (Linux - Pop_OS)
• HDD: Western Digital 1TB (Windows 10)
• PSU: Gigabyte P550B ATX 550W
• UPS: SMS Revolution II