I need a refresher on getting to post

[Invizibleyez]

My dad has a computer that is not posting. He asked me to take a look at it for him, which I gladly said I would. It's been a while since I've seen this problem, and If I recall correctly, a motherboard should be able to at least display that there is no system disk with no cpu/memory installed. I tried with those installed and it won't post, but I am now unsure what will happen if I just power up the empty motherboard. I fear the power supply could be to blame and it is a non-standard HP Pavilion Slimline s3037c TV PC. Any advice?

[The Teej]

In my experience, I've usually done a "bare bones" boot-to-post build with just a PSU, mobo+cpu, and a stick of RAM. Can't remember the last time I tried a pure mobo+cpu/psu build, although I seem to remember my mobos not liking that it hasn't got any RAM in there.

It's unlikely considering it has been working previously, but also do an out-of-case build too, just to make sure something isn't shorting the mobo inside the case.