Read Verify Scan Message on Screen

I started my ipod this morning and got some kind of diagnostic screen, which I tried to negotiate through and now it is completely locked up and says:

Read Verify Scan
Scan takes a while

Battery Check
Volts=476
Level=10

Canceled

MENU to continue

Although pressing menu does nothing and plugging into the computer, it's not recognized. Does anybody know what this screen means?