iMac Firewire 400 problem/upgrade question

A few years ago I made the switch from PC to Mac and I have a 17" 1.9GHz G5 (iSight) with 2.5gb RAM, but here recently my Firewire ports have both stopped working. Is there anyway to replace this or fix it? Around the same time that the firewire ports quit working 3 lines of dead pixels from top to bottom appeared. It hasn't overheated or anything and there is no flicker or odd behavior or loss of performance from the machine. Any thoughts on what this might be? I have been worried that my logic board might be going out. And aside from upgrading the memory are there any other hardware upgrades that I can perform? My apologies if this isn't in the appropriate category.

I'm afraid there isn't much you can do about the dead pixels. The cure for that is a new display. Dead pixels are not caused by a logic board defect.

As for the non working Firewire ports, run the Apple Hardware Test on your machine to see if it picks up on them: Link The Apple AHT will sometimes miss a hardware defect so keep trouble shooting.

Also check out this thread in another forum and try what he tried. Link Also try repairing permissions.

Regards.