HP ProOne 400 G1 Maintenance & Service Manual page 166

Table 10-1 Numeric Codes and Text Messages (continued)
Control panel message
Invalid Electronic Serial Number
Network Server Mode Active and No
Keyboard Attached
Parity Check 2
156 Chapter 10 POST Error Messages
Description
Electronic serial number is missing.
Keyboard failure while Network Server
Mode enabled.
Parity RAM failure.
Recommended action
Enter the correct serial number in Computer
Setup.
1.
Reconnect keyboard with computer
turned off.
2.
Check connector for bent or missing
pins.
3.
Ensure that none of the keys are
depressed.
4.
Replace keyboard.
Run Computer Setup and Diagnostic utilities.