General problemsv Follow the suggested actions in the order in which they are listed in the Action column until the problemis solved.v See Chapter 3, “Parts listing, System x3500 Type 7977,” on page 41 to determine which components arecustomer replaceable units (CRU) and which components are field replaceable units (FRU).v If an action step is preceded by “(Trained service technician only),” that step must be performed only by atrained service technician.Symptom ActionA cover lock is broken, an LEDis not working, or a similarproblem has occurred.If the part is a CRU, replace it. If the part is a FRU, the part must be replaced by atrained service technician.Fan problemsv Follow the suggested actions in the order in which they are listed in the Action column until the problemis solved.v See Chapter 3, “Parts listing, System x3500 Type 7977,” on page 41 to determine which components arecustomer replaceable units (CRU) and which components are field replaceable units (FRU).v If an action step is preceded by “(Trained service technician only),” that step must be performed only by atrained service technician.Symptom ActionThe server fan speed isabnormal. The following errorsmay occur:v 271 09/18/2006 15:20:12Fan/cooling device 3 Fanv Fan 3 Tach): Assertion: LowerCritical - going lowv Trigger threshold value:750.00 RPM. Trigger reading:0.00 RPM.1. Before you replace a FRU:a. Power off the server, and make sure that the fan cage is installed correctly.b. Use the following instructions to install the fan cage:1) Make sure that all cables that plug into the system board are connectedand routed properly underneath the plastic fasteners.2) Carefully slide the fan cage into both side wall rails until the fan cagelock holes snap into the two latch handles.3) Push down on both sides of the fan cage until it clicks in place.2. If the symptoms remains, contact IBM Service to assist in validating that thefollowing solution is appropriate: Place one more rubber grommet (FRU44E7524) underneath the fan cage power connector and reinstall the fan cage.118 IBM System x3500 Type 7977: Problem Determination and Service Guide
