Can anyone help with this problem I'm having?

I received an SE last week and it has a 50MB Quantum internal HD. I immediately copied over all of the software that was on it to an external just in case.

So I ran the SE with the internal fine for several days.

I let it sit for a few days and tonight it won't boot off that internal drive.

SCSI probe sees it at location 0, Norton utilities sees it but I can't mount it. I can't format it if I can mount it.

Any ideas?

Thank.

Paul