Dave is trying to update his MacMini with security updates for Mojave, but so far, they've been a disaster. Thunderbolt ports aren't reading his multiple monitors, causing him to reset his PRam. Now there's a new Mojave update and he's having mouse issues. Leo says that kernel panics are a sign of hardware issues. It could be a flakey power supply, a type-C port problem or badly soldered chip. It could be a driver issue, but it's usually indicative of hardware and that points to needing to call Apple.
Fred has a 2008 MacPro Cheesegrater, and he doesn't want to replace it. But it's having kernel panics. What can he do? Leo says a kernel panic is Apple's version of the blue screen of death. And it usually means it has a driver issue or a hardware issue. And sometimes, the first line of the panic will tell you something useful. Bad memory is a common cause of them. Power supply failing is an indicator. Try swapping out single RAM cards. That can tell Fred which RAM is acting up. He could just get one of the latest MacMini's and get a Thunderbolt 3 connection.
Jim is having boot problems with his iMac running Snow Leopard. It's constantly telling him to restart. He can't boot from a startup disk. Leo says it sounds like a Kernel Panic. It means that the computer just can't go on. So that means that there's a serious issue with the hardware. Jim can try zapping the PRAM by rebooting and holding down CMD-OPT-P-R. Sometimes that'll solve it. But it's more likely a logic board problem or a power supply.