POST Errors Occurred (6027) again

[Szabolcs Petho_1]

I read through other threads but I haven't found any reason for what can be wrong with our BL20p G3 servers.

If I reboot the servers I don't see any POST error coming up at POST screen.
All IML entry is marked to repaired and no POST errors exist there.
There is no ACU errors.
There is no disk firmware version problem.
These servers have no array controller battery.
We are running the latest PSP 7.40.

Time to time this error occurs in HP SIM. Is there any idea what to check, how to determine the source of this error? We have plenty of these servers and the issue is general, but still the servers seems to be healthy.

Thanks in advance.