It's hard coded to wait a certain number of seconds before giving up. I don't know how many seconds, they keep changing it with each software release.

After two hard disks respond, it continues the boot process. If only one hard disk responds, it waits a few more seconds for a second one to respond, then continues.

For this reason, a two-drive player will boot quicker than a one-drive player (since it continues the boot process as soon as two hard disks are found).

If you have a one-drive player, it is possible to hack the kernel so that it doesn't even bother to wait for a second drive. There were some features related to this in prior hijack versions, but I don't know if they're still there.