Were you synching over USB or ethernet?

It sounds like your primary master disk is a dead duck, bin it and get another one. If it clicks (the heads pulling in) and doesn't spin up, either the motor, the bearings, or the drive motor power circuitry has failed. Is the drive a Fujitsu? A lot of these failed in this way. You may be able to get an exchange drive from your national Fujitsu distributor.

The only other thing it might be is a loose jumper on the drive, but no jumper usually means Master drive anyway, so I doubt that's the problem. This actually sounds like you have the typical "off by one" row or column IDE cable re-connection problem, but since you say the disk was working correctly prior to this, that can't be the case.

I have no idea how a "power surge" could occur without knackering everything, but it is unlikely to have caused the death of the drive. Otherwise, the empeg or the second drive would have died with it. It's likely the drive motor bearings seized solid and the motor went short circuit drawing a high stall current on the 12V power line. The empeg would have survived (self re-setting fuses). Did you notice any smells like burning?

USB is supposed to be isolated with common earth, so I doubt the PC fried the empeg.

The emepg will not boot on what was your slave drive, you would need to either do major surgery (unwise) or re-format with the Drive Prep utility. This is something you have to do with the drive set up as master. See the FAQ.

I would remove both drives. Re-install only the 30G. Make SURE that you have got the cable correctly positioned on both the main board and the drive. Power on the empeg and observe what it says on the screen and also in the serial log. You should use the connector on the end of the cable for the drive, not the middle one, to ensure the drive will function in case the cable is a faulty one (pink stripe with black connectors). You should verify the cble is good by seeing if the other drive powers and spins up on the same cable connector: if not, the cable either needs crimping or replacing. You did say the Slave drive powered up, and I am assuming you mean it did this on the end connector of the cable which would mean it's OK. If you need to re-crimp the cable, read the FAQ.