mac mini start up noises

[alastaircmd]

My MacMini running OS X 10.5 has started causing trouble. It There have been a couple of kernel panics and then it started making a funny noise when starting up - it sounds like the normal start up sound but it gets cut off straight away. It does this three times and then starts. Programmes like Adobe Photoshop CS are quitting unexpectedly and Safari suddenly won't run. Last time the finder wouldn't even open. I have tried all the recommended fixes that I know of and have finally erased and re-installed on the macintosh volume (Windows Vista is on the other volume).
I thought I had fixed things with the reinstall but wanted to load Photoshop Elements 6. This loaded fine on my iMac but will not do so on the MacMini. It goes through the process of installing and then tells me it couldn't do it.
Now the computer has started making those funny start up sounds again.
Can anyone suggest anything new?

 

[blodwyn]

Funny mechanical noises can normally be attributed to either the hard disk or the cooling fan. If it were the cooling fan then problems would not start to show up until the cpu heated up, i.e. a few minutes, so maybe the hard disk is the culprit if the problems show up straight away.

If the funny noises are coming from the speaker, then I would suspect a memory issue, which seem to be the other main cause of system problems besides the hard disk.