IBM 2621421 Hardware Maintenance Manual - Page 114

Read This First Before you go to the check procedures, be sure to read this section. Important Notes Only certified trained personnel should service the computer. Read the FRU service procedures before replacing any FRUs. Be extremely careful during write operations such as copying, saving, or formatting. Drives in the computer that you are servicing might have been rearranged or the drive startup sequence might have been altered. If you select an incorrect drive, data or programs could be overwritten. Ensure that you replace FRUs with the appropriate model. When you replace the FRU, make sure that the model of the machine and FRU part number are correct by referring to the part list. FRUs should not be replaced because of a single, unreproducible failure. Single failure can occur for a variety of reasons that have nothing to do with a hardware defect, such as: cosmic radiation, electrostatic discharge, or software error. FRU replacement should be considered only when a recurring problem exists. In this case, clear the error log and run the test again. Do not replace FRUs if log errors do not reappear. Be careful not to replace a non-defective FRU. How to Use Error Messages Use the error codes displayed on the screen to diagnose failures. If more than one error code is displayed, begin the diagnosis with the first error code. The cause of the first error code can result in the other false error codes being displayed. How to Diagnose Mulitple FRUs If the adapter or device has more than one FRU, the error code could be caused by either FRU. Before replacing multiple FRUs, try removing or exhanging each FRU one by one in the designated sequence, to see if the symptoms change. What to Do First The servicer must include the following in the parts exchange form or parts return form that is attached to the returned FRU: 1. Name and phone number of servicer. 106 ThinkPad i Series 1400 HMM