IBM 2274 manual Start

Start

This is the entry point for all check procedures. The check procedures use failure symptoms, Power-On Self Test (POST) error codes, or beeps to help determine the defective field replaceable unit (FRU). Follow the suggested check procedures or use the diagnostics diskette to determine the problem FRU.

IMPORTANT: Replace FRUs ONLY when it is determined that the error is not a result of software, loose contacts, or dirty component surfaces. Any FRU change should be verified by running a complete test (“Diagnostics - All Tests” in PC-Doctor diagnostics program).

This book comes with a diagnostic program diskette. This diskette should be used ONLY with 2274 Service Level A (SL-A)IBM Personal Computers. Do not use this diskette on other models.

POST error codes and error messages are displayed on the screen after the IBM logo. Meanwhile, error beeps could be issued to help diagnose syste problem. Please refer to “Index of Symptoms, Messages, Error Codes, or Beeps” on page 38 for additional help.

All voltages in the check procedures are positive unless otherwise indicated. Use frame ground for all voltage checks unless otherwise specified.

IMPORTANT: There is a Power Override switch located at the back of the machine, just above the connector for the power cable. If the system does not power on after pressing the power button situated on the front of the machine, please check the power cable and the Power Override switch. If the Power Override switch is switched on, no power is supplied to the system.

NOTE: If the check procedures instruct you to replace a FRU and the error message persists, an option adapter card might be causing the failure. Remove all option adapter cards, one at a time, until the error changes or the problem is no longer apparent. Replace the last option adapter card removed.

Check Procedures 33