Internal HD Keeps Disappearing?!

[GMontag]

I've a HTPC Win7 Ultimate x32. Added a 1tb drive to the already loaded (with HD's) system and it will show up at boot (most times) and as I watch the drive via Explorer or am copying files to it, it disappears. Need to reboot it to see it, albeit or a short time.
Ideas? I've never seen anything like this.

 

[samuria]

How many hard drives have you got my first thought was power problems

 

[GMontag]

An SSD and 2 3.5". It's a 400+ watt P/S.
I thought of that and figured if it WAS a P/S problem why only that drive?

 

[samuria]

Use makers test software to check drive first job

 

[GMontag]

That was the first thing I did.
It's fine.

 

[samuria]

Change sata cable port

 

[GMontag]

We ARE thinking alike. That was the 2nd thing I did (the cable), then changed the port.
Today I change the P/S rail.
Same thing.
I'm beginning to suspect the drive, but it came OUT of this machine (HTPC) and has sat on the shelf for 6 months - doing nothing.
I think I've got to get into another machine and see.


************** UPdate ****************
Bloody HD failed just sitting on the shelf! Put a VERY old 500gb in it's place and it's dandy, man o' man.