How to Run the Advanced Diagnostics (8551)

1.  Power-on the computer.
2.  When the cursor moves to the upper right, press Ctrl+.Alt+.Ins to start the system program. If the IBM  logo does not appear, insert the backup copy of the Reference Diskette into  the diskette drive, press Ctrl+.Alt+.Del, then repeat this  step.
3.  Advance to the Main Menu.
4.  Press Ctrl+.A to run the system checkout.