Hi Sam;
Getting the Iomega Jaz drive connected to your G5 is going to require a host adapter card to give you a SCSI port to connect it to. These are becoming more and more difficult to find. As far as I know about the only ones still available are probably much more costly then the Jaz drive is worth.
Having said that if your system is having "finder" problems that you suspect are being caused by motherboard problems, I would suggest that you forget about the Jaz drive until you get those problems resolved first. Getting SCSI working on a G5 without any problems is a bit of a job all by itself. In your case with these other problems I think it would an insurmountable task.
Allan
