If I try to wake up the PC from sleep within 2 minutes of putting it to sleep, it will fail to wake properly 100% of the time (lights and fans come back on, but no signal to monitor or AFAIK any processes running etc)
If I try to boot the PC after shutting it down, it will fail to POST around 1 time in every 3 - regardless of when it was shut down (if it's been shut down for 3 minutes or 3 weeks doesn't seem to affect whether it will POST or not). No POST beep is made, nor any error beeps. At no point does the monitor receive signal, and not all the fans start.
Once the PC is working, it doesn't fail - when I've been in Windows etc, it doesn't get hardware issues or crash or anything - it's just waking from sleep too soon or sometimes booting up from shut down!
As I'm sure you can imagine, this is hugely inconvenient, and I can't afford to replace the machine! I've been told in general chit-chat that this is probably a power supply issue, but any help from the experts on here would be hugely appreciated.
Thanks in advance,