Dell Latitude LM Reference And Troubleshooting Manual

Also see for Latitude Latitude Z: System information guide Setup guide System information guide Specifications System information guide

Contents

Dell Latitude LM Reference And Troubleshooting Manual Manual pdf 44 page image

3-10 Dell Latitude LM Reference and Troubleshooting Guidesetting for each installed device. Then consult Table 3-4to configure the device for one of the available IRQ lines.NOTE: Installed devices cannot share the same COMport address. The default address of the computer’s serialport is COM1.Troubleshooting ProceduresThis section provides troubleshooting procedures forbuilt-in components (such as the display) and for externaldevices that connect to the computer (such as an externalmonitor). Before performing any of the procedures in thissection, see “Basic Checks” found earlier in this chapterand read the safety instructions at the front of this guide.Then perform the appropriate troubleshooting procedurefor the component or equipment that is malfunctioning.NOTE: When you see the question “Is the problemresolved?” in a troubleshooting procedure, perform theoperation that caused the problem to see if the problemstill occurs.Troubleshooting a Wet ComputerLiquids, spills and splashes, rain, and excessive humiditycan cause moisture damage to the computer. If the com-puter gets wet or if condensation forms on the computerbecause of humid conditions, use the followingprocedure:1. Turn off the computer, and disconnect it from theAC adapter. Then disconnect the AC adapterfrom AC power. Turn off any attached periph-erals, and disconnect them from their powersources and then from the computer.2. Remove any installed batteries.Wipe off each battery, and store it in a safe place todry.3. If the options bay slot is wet, remove the devicefrom the bay. If the PC Card slot is wet, removethe PC Cards. Put the device and cards in a safeplace to dry.Table 3-4. IRQ Line AssignmentsIRQ Line Used/AvailableIRQ0 Generated by the system timerIRQ1 Generated by the keyboard controller to sig-nal that the keyboard output buffer is fullIRQ2 Cascade to second interrupt controllerIRQ3 Used by the infrared port (COM2)IRQ4 Used by the serial port (COM1)IRQ5 Used by the audio controllerIRQ6 Generated by the diskette drive controllerto indicate that the diskette drive requiresthe attention of the microprocessorIRQ7 Used by the parallel portIRQ8 Generated by the system RTCIRQ9 Software redirect to INT0AIRQ10 ReservedIRQ11 ReservedIRQ12 Generated by the keyboard controller to indi-cate that the output buffer of the integratedtouch pad or external PS/2 mouse is fullIRQ13 Used by the math coprocessor on themicroprocessorIRQ14 Generated by the hard-disk drive to indi-cate that the drive requires the attention ofthe microprocessorIRQ15 ReservedNOTE: For the full name of an abbreviation or acronym usedin this table, see the Glossary in the online System User’sGuide.WARNING: Perform step 1 of the following proce-dure only after you are certain that it is safe to doso. If the computer is connected to an alternatingcurrent (AC) power source, Dell recommends turn-ing off AC power at the circuit breaker beforeattempting to remove the power cables from ACpower. Use the utmost caution when removing wetcables from live power.