Mac Mini not waking up correctly

I hope this is in the right place. I don't know if it's hardware/firmware or software. I do know the Mini is a desktop, so I think this might be the place

My shiny new Mac Mini doesn't wake up properly.
If it's only in sleep mode for a short while all is OK, but if it's in sleep mode for an hour or more it either doesn't wake up the screen, or if it does wake up the screen I get a black screen with a white (outline) mouse pointer. The mouse pointer will move if the mouse is moved.
I can shut the machine down and put it to sleep again, using the keyboard shortcuts, but it still won't wake properly.
The "Genius" in the local Apple store, tells me to re-intsall Snow Leopard.
I'd rather not have to do this, as I've just spent the best part of a week installing and re-intsalling Tiger on my son's G5 PPC, and I've had enough of re-installing OSX!!!!!

Any ideas?

I really don't want to have to shut the machine down everytime I leave it, as the power buton in on the rear of the mini and it's difficult to get to as the mini is in it's own liitle home, tucked out of the way.

TIA

Darren

It might be a graphics card issue. Get the OS install disc, and then find Disk Utility, followed by Apple Hardware Check. This will check to see if the graphics card is the issue. If not, then the Genius might be right- you'll have to reinstall the OS. I sincerely hope you backed up all of your stuff.

Thanks I will give it a go.
As for backing stuff up... There's nothing to back up as yet. Anything I want to use gets pulled off the network, so the machine itself only carries the software that came with it.

I've noticed something...
This morning, I woke the Mini up and as usual, I got nothing on the screen, but the mac itself did wake up as the light went from slowly fading to full on.
I then sent the machine back to sleep using the keyboard shortcut and rather than go to sleep, the machine rebooted.
Is there a deep sleep mode for longer sleep durations?

If this happens all the time I'll be happy. I can't get to the power button that easilly, so as long as the machine starts up without me taking the stack apart then I'm happy. I will try the hardware check and maybe the re-install, as I have nothing to lose but time.

Thanks again

Darren

Hi Darren,

Just so you know, my new mini's sleep function works very well, overnight or days at a time.

I tend to agree with Chris that it's a video driver issue ... what monitor are you using and now old or new is it ?

Mac and other computer makers do not announce it, but there are several stages to the sleep mode, some of which you may already know.
Stage one: Screen Dims. Happens after inactivity.
Stage two: Screen Shuts off. This is normal. HDD and all other components remain active.
Stage three: Peripherals, Applications with saved work, minor active programs are shut down.
Stage four: Processor begins to slow. Unsaved work is automatically saved on the drive as an open window with text. Graphics Cards/Accelerator slows.
Stage five: Processor at 'sleep' speed. Graphics off. HDD Parked. Fans off.
These stages all happen within a very short time, the time depending on how hot the computer is, how many programs you're running, and how many things have not been written to the HDD yet. In a case like yours, the computer may be suffering from a prolonged 5th stage, in which outside stimulus will not start the HDD.
Windows 98 and XP both suffer from this, but Mac cases are rare. Try hitting the power button very briefly to start it up.

TechTool Pro

You could also, if you have TechTool Pro, go in and do a "volume rebuild", in eDrive mode, this will usually fix the problem and save you a complete reinstall.