Last year the FireWire port on my iMac had a little adventure and ceased to work, as did the computer. It then decided to work the next day before I took it to be repaired. Anyway, Apple repaired it and they even replaced the screen. Now recently I have tried to use the port with an external drive and several other devices. All of the devices light up suggesting that they are being powered up none of them mount to the computer. Any ideas on what the cause could be, if I could fix it myself or do you think I'll have to trek it back to the Store for repair again. Note: I have tested it with multiple peripherals and none of them work with the iMac but do work with any other Macs I use them with.