A26

Explanation
A machine check interruption occurred on the only online processor. The machine
check interruption code associated with the interruption is incorrect. No recovery was
possible.

System action
The system issues message BLW006W. The system enters wait state
X'A26'.

Operator response
To recover possible unrecorded machine check error records, write a
stand-alone dump. Retain the dump. Contact hardware support.

Source
Machine check handler (MCH)