A Voltage Regulator Module (VRM) is a small module that installs on a motherboard to regulate the voltage fed to the microprocessor.
CAUTION: Do not attempt to service the system except as explained in the documentation. Only trained service technicians should remove the system cover to access any of the internal components. Refer to the documentation for your server for complete safety information before attempting to service your system.
Visually Inspecting Your System
Improperly set controls and loose or improperly connected cables are common causes of problems with hardware components. When investigating a system problem, first check all the external switches, controls, and cable connections. If this does not resolve your problem, then visually inspect the system's interior hardware for problems such as a loose card, cable connector, or mounting screw. Refer to Visual System Inspection for instructions about how to verify that your hardware components are properly installed.
Troubleshooting the VRM Component
Following are possible causes of problems with the VRM component:
Voltage problems often indicate a problem with the voltage components. To isolate the root cause of a failure of a given voltage, verify that the source of the suspect voltage is functioning properly. For example, if voltage CPU1 Core is failing, verify that its source(s), 12V Main and 5V Main are functioning properly.
Run the diagnostics tests for voltage modules to locate and diagnose voltage problems.
Several voltages are monitored and tested. Of these, some are directly supplied by the power supply. Most, however, are voltages derived from bulk voltages. For example, some are generated by the point-of-use VRMs (FRUs) associated with CPU0 and CPU1 and their respective memories.
Troubleshooting the Service Processor