Troubleshoot

Troubleshooting
This portion of the exam is one that is very difficult to outline in a study guide and is where your experience is really being tested. There are far too many different errors and solutions to be written here. We have included some general troubleshooting information and common problems for various components, however, this is by no means a comprehensive list. This is where your on the job experience and work in your home lab are necessary.

Below is a list of useful tools for hardware troubleshooting:
• Standard and Phillips Screwdrivers - various sizes
• IC ROM Puller - For upgrading BIOS chips
• Multimeter - A necessary tool for troubleshooting electrical issues such as the power supply. It can also be used to do a resistance test. When performing this test make sure that the power to the system is unplugged.
Test Good reading
Speaker Resistance 8 ohms
Fuse Resistance 0 ohms
Capacitors(DC) 5V (most of them)
The following table shows the readings that you should see for various multimeter tests:




Some components of a PC are field replaceable and some are not. Common Field Replaceable Units(FRUs) are below:
• Monitor
• Keyboard
• Mouse
• Floppy Drive
• CDROM
• Hard Drives
• Printer
• Video Adapter
• Sound Card
• Network Card
• Motherboard
• Power Supply
• Processor
• CMOS Battery
• RAM
Beep codes vary depending on the manufacturer of the BIOS. Below are some of the common beep codes for an Award BIOS.
Beep Code Meaning
1 long System memory failure
1 long then 2 short Video controller failure
1 long then 3 short Video controller failure
Continuous Video or memory failure

Below are the IBM error code families and the component that the error code relates to:
Error Code Family Error Type
1xx System board errors
2xx Memory (RAM) errors
3xx Keyboard errors
4xx Monochrome monitor errors
5xx Color monitor errors
6xx Game control adapter errors
7xx 8087 or 80287 math coprocessor errors
9xx Parallel printer adapter errors
10xx Reserved for parallel printer adapter
11xx Asynchronous communications adapter errors
12xx Alternate asynchronous communications adapter errors
13xx Parallel printer adapter errors

• Lost BIOS password - Most newer motherboards have a jumper that can be used to clear the CMOS memory. Typically this involves opening the PC, changing the jumper to a special setting, and then booting the PC. If the memory has been cleared, you power the PC down and put the jumper back to its previous position
• System clock is not keeping correct time - This is typically caused by the CMOS battery failing or running low voltage. Usually, replacing the CMOS battery will fix this.
• System locks up consistently a few minutes after power up - This is usually associated with a failed processor fan or general overheating. Boot the system with the case off and see if the fan is running. If not, the fan and likely the processor will need to be replaced.
• System appears completely dead(no visible activity during powerup) - Check the external power cable and make sure that it is plugged into a working outlet and securely plugged into the unit. Next, make sure that the on/off switch is set to "On" and that the 115/230 switch is set to the appropriate setting for your location. Verify that the internal power connection from the power supply to the motherboard is firmly connected. A multimeter can be used to narrow determine how far the power is getting. Start at the outlet and work your way inside. Finally, remove all unnecessary components from the motherboard to see if one of them is overloading the power supply.
• Front panel lights come on and the power supply fan runs, but no other activity is present - Try swapping out the power supply. If this doesn't fix the problem, remove all unnecessary components from the motherboard to see if one of them is overloading part of the power supply.
There are 2 types of memory errors:
• Soft-memory errors - These are occasional strange behaviors that can usually be cleared by rebooting.
• Hard-memory errors - Caused by a hardware failure related to the RAM and will usually display a message on the screen or create a beep code. Can be isolated by removing memory chips 1 at a time.
• System locks up while counting RAM - Usually requires that the processor be replaced

Keyboards can have a variety of symptoms including:
No characters appearing on the screen
6 beeps on boot
A 301 error code
Keyboard is locked - Unlock It error message
Keyboard Error - Keyboard Test Failure
KB/Interface Error - Keyboard Test Failure

The most common causes for these problems is:
Incorrect keyboard type in BIOS or Windows
Keyboard not properly connected
Blown fuse in back of keyboard


Mice:
Cursor skips around or gets stuck - This is usually caused by dirt and lint inside the mouse that needs to be cleaned.
Doesn't move at all - Can be a configuration error caused by an IRQ or address conflict, conflicting device drivers loaded in autoexec.bat and config.sys or can be caused by a hardware failure. If none of these are causing it, it is likely a problem with the port on the motherboard.

Video:
• There are a variety of problems that can occur from misconfigured drivers and settings. When possible, verify that the correct drivers are loaded and check for IRQ and memory address conflicts
• Screen goes blank after a while - This is usually due to Power Management settings in the BIOS
• The screen flickers - Usually caused by the refresh rate being set too low.
• The output on the screen is garbled or looks like a bunch of moving lines - This is most often caused by setting the resolution, color depth or refresh rate at a higher level than the monitor supports. To correct this, press F8 on boot and select "Safe Mode" from the menu. Set the display settings to appropriate levels.
• No display at all and you suspect hardware - Make sure that the monitor is plugged into a working outlet. Make sure that the contrast and brightness settings have not been turned all the way down. Make sure that the monitors signal cable is properly connected to the PC and that the video card is properly seated in the slot.
Floppy Drives:
• The floppy drive will not read any disks - Check for IRQ and memory address conflicts. Make sure that the internal power cable is connected from the power supply to the drive. Verify that the FDD cable is properly connected to the motherboard and the drive and that the pin 1 orientation is correct. You can also narrow down the problem by swapping out the drive and cable one at a time to determine if the problem is with one of them.
• The system will not boot from the floppy drive but works fine after boot - This is usually caused either by a problem with the floppy or by an incorrect boot sequence in the BIOS
Hard Drives:
• Make sure that the drive is properly connected and using the correct pin 1 orientation.
• Make sure that there is only one device connected to the cable that is configured as master.
• There are a variety of problems that can occur from misconfigured settings. Verify that the correct drive settings are reflected in the BIOS settings. Common error messages that can occur when these are incorrect are "Drive Type Mismatch" and "Invalid Media Type".
• Check for IRQ and memory address conflicts in Windows.
• The system will not boot. If booting from a floppy, the drive can be accessed from a DOS prompt - This usually indicates that the boot files are missing or corrupt. Change directories to the A drive(with the boot disk inserted) and type SYS C: to restore the boot files.
• From a DOS prompt, you receive a "Boot Disk Failure" or "Missing ROM Basic Interpreter" error message when trying to view the contents of the hard drive - Try restoring the master boot record by using the FDISK utility as follows: FDISK /MBR.
• If all configuration settings are correct and the drive cannot be accessed after booting with a boot disk and an "Invalid Drive" or Invalid Drive Specification" error message appears, the disk will need to be formatted and reconfigured.
• If the EIDE or IDE controller is dead and is hardwired to the system board, an IDE or EIDE controller expansion card can be used without having to replace the motherboard.
• If it is a SCSI drive, make sure that the hard drive is using a unique SCSI ID on its chain and that proper terminiation is in place.
CD-ROMS:
• Make sure that the drive is properly connected and using the correct pin 1 orientation.
• Make sure that there is only one device connected to the cable that is configured as master.
• Make sure that the drive is configured correctly in the autoexec.bat for a line similar to C:\MSCDEX.EXE /D:mscd001 /L:%CDROM% and config.sys for one like device=aspicd.sys /D:mscd001.
• If the CD tray has become jammed and will not open, use a paperclip or other long thin item into the tray release access hole.
• If the EIDE or IDE controller is dead and is hardwired to the system board, an IDE or EIDE controller expansion card can be used without having to replace the motherboard.
• If no sound is heard when playing a CD, make sure that the sound card is properly configured and that the cable is connected between the CD-ROM and the sound card.
• "Data error reading drive C:" or "Sector not found" error messages consistently occur - This is typically caused by a dirty drive that needs to be cleaned.
Modems:
• Check for I/O and IRQ conflicts
• You may need to configure a modem initialization string using the AT Command Set.
• Check configuration settings such as disabling call waiting or dialing a 9 first for an outside line.
• Refer to ISP instructions for advanced configuration options such as flow control, parity, etc.
• Make sure that the correct driver is loaded for the modem.
• As with any component, make sure that it is properly seated and all cables are correctly attached.