Step 1540B-3One of the FRUs remaining in the system unit is defective.If the following steps call for a system board to be replaced, see notes on page 2-1.1. If the disk LED is on, turn the power off and exchange the following FRUs inorder:a. Memory modules (pair)b. Riser cardc. System board (See notes on page 2-1)2. If the disk LED is off, turn the power off and exchange the following FRUs inorder:a. Processor cardsb. Memory modules (pair)c. Riser cardd. System board (See notes on page 2-1)Does the operator panel stabilize for more than 60 seconds with code FDC,FF2, FF3, or F4D displayed, or is one of these codes displayed immediatelybefore the system unit attempts to restart?NO Reinstall the original FRU.Repeat the FRU replacement steps until the defective FRU is identified orall the FRUs have been exchanged.If the symptom did not change and all the FRUs have been exchanged,call your service support person for assistance.If the symptom has changed, check for loose cards, cables, and obviousproblems. If you do not find a problem, return to “Step 1540B-1” onpage 2-39 in this MAP and follow the instructions for the new symptom.YES Go to "Map 0410: Repair Checkout" in the Diagnostics Information forMultiple Bus Systems.Chapter 2. Maintenance Analysis Procedures (MAPs) 2-41