IBM 7985 Problem Determination And Service Manual

Universal Serial Bus (USB) port problemsv Follow the suggested actions in the order in which they are listed in the Action column until the problemis solved.v See Chapter 4, “Parts listing, System x3655, Type 7985 and 7943,” on page 93 to determine whichcomponents are customer 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 USB device does not work. 1. Make sure that:v The correct USB device driver is installed.v The operating system supports USB devices.2. Make sure that the USB configuration options are set correctly in theConfiguration/Setup Utility program menu (see the User’s Guide for moreinformation).3. If you are using a USB hub, disconnect the USB device from the hub andconnect it directly to the server.4. Move the device cable to a different USB connector.Video problemsSee “Monitor problems” on page 43.Light path diagnosticsLight path diagnostics is a system of LEDs on various external and internalcomponents of the server. When an error occurs, LEDs are lit throughout theserver. By viewing the LEDs in a particular order, you can often identify the sourceof the error.When LEDs are lit to indicate an error, they remain lit when the server is turned off,provided that the server is still connected to power and the power supply isoperating correctly.Before you work inside the server to view light path diagnostics LEDs, read thesafety information that begins on page vii and “Handling static-sensitive devices” onpage 107.If an error occurs, view the light path diagnostics LEDs in the following order:1. Look at the operator information panel on the front of the server.v If the information LED is lit, it indicates that information about a suboptimalcondition in the server is available in the BMC system event log or in thesystem event/error log.v If the system-error LED is lit, it indicates that an error has occurred; go tostep 2 on page 50.The following illustration shows the operator information panel.Chapter 3. Diagnostics 49