now I can't get past the gray screen. I have not tried the firewire link but I am wondering if something failed. I have remove the two cards USB and SATA controller and the extra HD in slot 2 under the main HD. the DVD drive has been unplugged as well. I took the battery out and put it back. I have also resetted the pram but to no avail. I only have a Tiger disc so is it possible to boot from that and repair permissions and HD or do I need to track down a Leopard disc? What would be the signs if the motherboard, logic or any other boards were failing?