Today, when I clicked shutdown on my computer, the screen went blank and was unresponsive, but the power remained on. I couldn't get the screen to come back and had to power it down manually. Just got a new PSU, and monitor is good, any thoughts?
Similar thing happened to me from day one of bring home my new build, only mine would shut down okay, I just couldn't restart Windows. If I clicked "Restart" I lost the monitor signal, but the PC remained on but unresponsive. Every time a software installation requested a restart I had to click "No" and shut down instead. - I suspected a faulty or incompatible PSU so I ripped it out and fitted a different one, this time a dearer one with a trusted brand name. Problem solved.
Your problem is slightly different but may be caused by the same thing (the PSU).
The one I removed was a cheap unit with a brand-name I'd never seen before, fitted by the guy who built my PC (local computer builder). He went on holiday the very day I brought it home (typical), so I fixed it myself.
I think it might be a problem with the PSU as well. I recently sent this computer back with a faulty PSU and they replaced it, but I saw the receipt and they only payed 42$ for it. I know that manufacturers may get some discounts, but I think 42$ is a little cheap.
I mean the PSU works fine a seems to be powering my PC ok, but I know it can't be good to not allow your computer to shutdown ever. Regardless, I'm not sending a PC back to them again because they take an entire month to get it back to me. I'm taking it into a computer repair shop this weekend, I'll tell them to put a quality power supply in there if it is truly the problem.