When the iPod is plugged into my Mac it behaves perfectly well, I can sync and update without problems. As soon as I...

The iPod was connected to my MacPro via a Firewire 800/400 adapter which got kicked, the 800 end broke resulting, in a...

I have been running High Sierra on my 3,1 2008 8-core Mac Pro since September 2018, using DosDude1's installation. Has been relatively problem-free, though sometimes feels slower than El Capitan. One fault that took me a while to fix was random logouts for no apparent reason, but I pinned it down to a conflict between my GPU's. I have an unflashed EVGA Nvidia GTX 760 which performs well, and gives me CUDA in Photoshop and After Effects, but when problems do arise it's handy to be able to see the EFI boot screen, which I can't do with the PC Nvidia card, so I left the old ATI Radeon 2600XT installed powering a small monitor. This never caused any problems in El Capitan, but seems to be the cause of the random logouts, as they haven't occurred since I removed it. I installed a later Atheros Wifi card shortly after buying the machine, as the machine came without Wifi, and there have been no problems with High Sierra and WiFi. DosDudes Patch Updater allows AppStore system updates to run. I ran a security...

Try a hard reset before doing anything that involves opening the case. Press menu and the centre button together and hold for a few seconds and the apple should appear, and the system should restart. With luck this should be enough to fix the problem.