Dear Gurus, Mr. Davis wrote: "DTT , Brian, says he is 99% sure it is the I/O board. I assume this is the same power I/O board others have had replaced. He says $150 and i should be up and running." I've torn my 2400 down once and sent it twice to DT&T for an I/O board and a CPU repair. Their prices were reasonable and their turnaround speed was remarkable - both times I had my 2400 back within ten days. When people talk blithly about upgrading to OSX or complain about the cost of fixing an older (but otherwise satisfactory) machine, I shudder. If I sell my 2400/240 instead of getting it repaired and buy one of the new PB G4's, I lose 7.6.1, 8.6 and all the apps specific to them. I must upgrade, load and tweak all my apps: hundreds of dollars and days of my time adjusting a tool instead of using it to make my living. Send it to DT&T. Donald McCaig