70 Chapter 4Parallel/Serial PortsExecute “Load BIOS Default Settings” in BIOS Setup to confirm ports presence before diagnosing anyparallel/serial ports problems.Serial or parallel port loop-back testfailed.1. Make sure that the LPT# or COM# you test is the sameas the setting in BIOS Setup.2. Loop-back.3. Main board.Printing failed. 1. Ensure the printer driver is properly installed. Refer to theprinter service manual.2. Printer.3. Printer cable.4. Main board.Printer problems. 1. Refer to the service manual for the printer.KeyboardSome or all keys on keyboard do notwork.1. KeyboardPower SupplyPressing power switch does not turn offsystem. (Only unplugging the powercord from electrical outlet can turn off thesystem.)1. Ensure the Soft-off by PWR-BTTN. in BIOS Setupof Power Management is not set to Instant-off.2. Power switch cable assemblyPressing power switch does not turn onthe system.1. Ensure the power override switch (situated at the back ofthe machine, just above the connector for the powercable) is not set to OFF.2. Power switch cable assembly.Executing software shutdown fromWindows98 Start menu does not turn offthe system. (Only pressing power switchcan turn off the system).1. Load default settings.2. Reload software from Recovery CD.No system power, or power supply fan isnot running.1. Power Supply2. Main boardOther ProblemsAny other problems. 1. Undetermined ProblemsError Symptom Action/FRU