Rock64 generally unstable?

[Sputnik]

For weeks I have been trying to get my Rock64 4GB into a stable system state.

It does not work properly and there are many problems with it. I tried a lot for weeks until I realized that it wasn't the operating system or a program. Even when idle on a freshly installed system (stretch-minimal-rock64-0.7.11-1075-arm64.img), error messages appear on the console after some time and the system hangs.
Copying large files reproducibly brings the system to a standstill. I am using an original power supply, the CPU temperature is not higher than 55°C.Now I suspect a hardware problem.

- Is there a program to check the hardware reliably?
- What else can I try?

Regards, Sputnik


Message from syslogd@nextcloudpi at Feb 25 20:39:10 ...
 kernel:[275628.666184] 3f60: 0000000000000001 0000000000000001 0000007f99e53d88 0000007f99e574c8

Message from syslogd@nextcloudpi at Feb 25 20:39:10 ...
 kernel:[275628.678344] 3f80: 0000007f99e56000 0000000000000001 0000007f99e58a20 0000000000000000

Message from syslogd@nextcloudpi at Feb 25 20:39:10 ...
 kernel:[275628.690489] 3fa0: 0000000000000000 0000007ff3c3dc20 0000007f99d46300 0000007ff3c3dc20

Message from syslogd@nextcloudpi at Feb 25 20:39:10 ...
 kernel:[275628.702503] 3fc0: 0000007f99dafa7c 0000000060000000 0000000000000000 000000000000005e

Message from syslogd@nextcloudpi at Feb 25 20:39:10 ...
 kernel:[275628.714493] 3fe0: 0000000000000000 0000000000000000 0000000000000000 000000000000000