Chosen Solution
When i power on the mac with the mouse and keyboard coencted to USB the MAC don´t start and tell me a setup USB error. If i disconect the USB mouse and keyboard the computer boot fine, but if i conect the USB mouse or keyboard the computer give me a screen with “you have to restart the computer”, restart and don´t boot again.-…please help!!! i thought this was caused by damage on the logic board, so i buy one on ebay, replace it and the same problem again. Maybe it is somewthing with software or OS, but i can´t do anything without a mouse or keyboard!!!! please help me!!! don´t know what to do
Change the keyboard and mouse, they may be trying to draw to much power.
If you have access to another PowerPC based mac, retrieve your harddisk from your G4 and connect it to the other mac. Do a clean install on it and see if that fixes your problem. Otherwise a PCI USB card may do the trick, but you already tried two logicboards, so i’d rule out a software error first.
