I finally spent $60 on a decent PSU tester and it caught a bad 12V rail that a multimeter missed
Client's rig was randomly rebooting and I was about to blame the RAM until the tester showed the 12V rail sagging to 10.8 under load. Anyone else got a cheap tool that ended up saving them from a wrong diagnosis?
Bought a $12 outlet watt meter once just to check if my fridge was dying, ended up finding out my whole apartment circuit was wired wrong. Landlord was not happy about that one.