My MythTV based PVR rig took a hit about 6 months ago during a major power surge and needed a motherboard replacement (​GA-B450M-K V2.0).

It initially appeared that the Athon 200GE CPU and RAM we're still functioning correctly, but I'm seeing regular stability issues. In addition I was trying to compile some new DVB debugging tools and the compiler keeps crashing out at random points.

I've tried stress-ng and memtest+ and whilst memory appears to be OK after 12+ hours the stress test shows a couple of issues

stress-ng --cpu 0 --verify --verbose --timeout 15m

stress-ng: debug: [86249] cpu: [86249] started (instance 30 on CPU 1)
stress-ng: debug: [86218] 32 stressors started
stress-ng: debug: [86250] cpu: [86250] started (instance 31 on CPU 1)
stress-ng: fail:  [86223] cpu: drand48 error detected, failed sum
stress-ng: fail:  [86221] cpu: drand48 error detected, failed sum
stress-ng: fail:  [86227] cpu: drand48 error detected, failed sum
stress-ng: fail:  [86245] cpu: drand48 error detected, failed sum
stress-ng: fail:  [86224] cpu: prime error detected, number of primes has been miscalculated
stress-ng: debug: [86223] cpu: [86223] exited (instance 4 on CPU 1)

I've now swapped out the CPU for a brand new Ryzen 3400G, but I'm see seeing compiler errors and ongoing errors with stress-ng

stress-ng: fail:  [18743] cpu: gray code error detected, sum of gray codes between 0x00000 and 0x10000 miscalculated
stress-ng: fail:  [18734] cpu: prime error detected, number of primes has been miscalculated

It doesn't look like a system overheating issue, so I'm going to try a memory swap next. 

Meanwhile I'd be interested to hear any other debugging tips.