How to Diagnose PC Hardware Problems

Use the general diagnosis table below as a guide to finding the problem component. We have separate diagnostic pages for each component of the PC.

Symptom	Check Click on underlined items for further information
When I turn it on... It makes no sound and there are no lights	Check the Power Supply Check the Motherboard Check the CPU
When I turn it on... It just beeps	Read our Beep Codes List Check the Keyboard Check the Video Card Check the Memory Check the Motherboard
When I turn it on... It sounds normal but the screen is blank	Make sure the monitor has power Check the connection to the video card Check the Video Card
When I turn it on... It starts up but never loads the operating system	Check the Hard Disk Check the Memory Check the Motherboard Check the CPU
When I turn it on... It freezes BEFORE the operating system starts loading	Check the Keyboard Check the Video Card Check the Memory Check the Power Supply Check the Motherboard Check the CPU
When I turn it on... It freezes WHILE the operating system is loading	This is probably a software problem not covered in this hardware guide. If you are using Windows, try booting into safe mode by holding down the "F8" key or in some cases the "CONTROL" key.
While it is on... It makes a screeching or other loud noise	Check the Power Supply, CPU, Case or other Internal Fans Check the CD-ROM Check the Hard Disk Check the Floppy Drive
While it is on... It shuts itself off	Check the power features in the BIOS Check the power features in the Windows Control Panel Check the Power Supply Check that all fans are working Check for the accumulation of dust
If the problem occurs in association with a specific hardware component, visit the diagnostic page for that particular part.
Software Issues are not covered in this hardware guide.

The Floppy Disk Drive

The floppy drive is slowly, but surely, becoming obsolete. Only capable of storing 1.44 megabytes of data per disk; it has very limited usefulness. Storage space on CDs and DVDs is hundreds or thousands of times greater. Quick and easy portable data storage is conveniently handled by USB flash drives.

Once all software is designed to support other mediums, little or need will exist for the trusty old floppy.

Floppy Drive Overview Diagnosing Floppy Drive Problems Installing a Floppy Drive Purchase a Floppy Drive

How a Floppy Disk Drive Works

The floppy disk drive is a device that records data onto a removable storage disk called a floppy disk. Floppy disks, also called "floppies", are the most basic storage medium for data. However their limited capacity, typically 1.44 megabytes, makes them of limited use.

A floppy disk can be used to copy files from one PC to another PC or for making backup copies of files.

Replacing a floppy drive is very easy and inexpensive to do should the need arise.

PC based floppies only a hand few of years ago were 5.25 inches. Before the mainstream introduction of the home computer, floppies of 8 and 10 inches were in wide use. Now floppies have a more rigid outer shell and are 3.5 inches. However their low capacity make them of limited value.

Floppy capacities, in the PC era, started at 360KB, climbed to 1.2MB then the smaller 3.5 inch floppy was introduced. The new floppy could could hold 720KB of data and then doubled to 1.44MB in 1987. A 2.88MB disk was developed by Toshiba but it never caught on.

There are a couple of other removable media disk products on the market, such as the Iomega ZIP drive. These specialized drives use a proprietary disk media to record considerably more data than will fit on a conventional floppy.

How to Diagnose Floppy Drive Problems

These are some symptoms that may be caused by the floppy drive. Other components may also cause these same symptoms, check the general diagnosis page for more information.
Symptom	Check Click on underlined items for further information
Indicator light never goes on	Check that the power connector is properly and securely connected. Check that the interface cable to properly and securely connected to both the drive and the motherboard.
Indicator light never goes off	The interface cable may be reversed. Check the connection to the drive and to the motherboard.
Drive type mismatch during boot	Check for proper configuration in CMOS. The floppy drive may need to be replaced.
"Invalid media" or "Track 00 bad" error when formatting	The floppy disk may be defective. The drive may not be properly configured in CMOS. You may be using the wrong floppy disk density for your drive.
The same directory is displayed for different diskettes	Refresh the view. Reinsert the disk, making sure it goes in all the way. Check that the interface cable to properly and securely connected to both the drive and the motherboard. The floppy drive may need to be replaced.
"Drive not ready" error	There is no disk in the floppy drive. Reinsert the disk, making sure it goes in all the way. The floppy drive may need to be replaced.
"General failure" error	The disk in the drive is not formatted. You may be using the wrong floppy disk density for your drive. The drive is out of alignment.
"Sector not found" error	The drive is out of alignment.

How to Replace a Floppy Disk Drive

Caution: Please read our safety information before attempting any testing or repairs.

Before replacing any of the fans, unplug the PC to avoid an electrical shock hazard. Exercise caution as there are sharp edges on a PC and its components. Always wear a static electricity discharge strap when working with your PC's components to avoid damaging your PC.

1. Unplug the PC.
2. Disconnect all wires from the back of the PC.
3. Open the case.
4. If replacing a floppy drive disconnect the power and interface cables from the drive and remove the retaining screws from either side of the drive.
5. Identify the position of the #1 pin on the interface connection on the back of the drive.
6. Choose the location for the floppy drive so that the drive will have a opening in the case's face plate and so that the power and interface cables will reach the drive.
7. Mount the drive so that he eject button is under (not over) the slot for the floppy.
8. Connect the interface cable so that the cable's #1 pin matches the drives #1 pin.
9. Connect the power wire to the drive.
10. Position the drive and secure with the mounting screws. Always use the screws supplied by the manufacturer. Screws of the wrong size or length can damage the drive.
11. If it is not already, connect the interface cable to the motherboard's controller labeled "FDD" so that the cable's #1 pin matches the motherboard's #1 pin.
12. Double check all of your connections.
13. Replace the cover.
14. Reconnect the wires removed in step 2.
15. Plug in the PC.
16. It may be necessary to configure this drive in the BIOS settings.

CD-ROM Drive

CD-ROM Overview

Diagnosing CD-ROM Problems

How to Install a CD-ROM

CD-ROM Overview

The CD-ROM drive is a device that reads information or music (technically, digital music is also information) off of a compact disk (CD). CD-ROM stands for Compact Disc Read Only Memory.

Caution: Please read our safety information before attempting any testing or repairs.

The CD is spun at high speed inside the drive while a laser is directed at the surface to read the data or music. The CD-ROM is referenced as a 12X or 12 speed (or any number). This simply means that it spins the CD that many times faster than the original industry specification. So, a 48X CD-ROM spins the CD up to 48 times faster than the original specification. Faster is better.

CD-ROM drives, like hard disk drives, also measure their performance with seek time, access time and transfer rates. Which respectively reflects the amount of time it takes to find a file, to begin transferring it and how much data it can transfer per second.

For greatest operating efficiency, the CD-ROM drive should be connected to the second IDE controller. Although it can be connected to the first IDE controller behind the hard disk, only one device can communicate with the controller at a time, thus causing a bottleneck.

Mini CD's and business card CD's are not recommended for use in a CD-ROM because of the risk of damage. Although mini CD's are convenient, they occasionally become unstable and destroy the CD-ROM.

How to Diagnose CD-ROM Problems

These are some symptoms that may be caused by the CD-ROM. Other components may also cause these same symptoms, check the general diagnosis page for more information.
Symptom	Check Click on underlined items for further information
I cannot access the drive and the light does not go on	Check that the power and controller cables are securely attached to the drive. Verify that pin #1 of the controller cable is matched to pin #1 on the drive and on the motherboard. The operating system may not be configured to use or "see" the drive. If it never worked, verify that the jumpers on the drive are set correctly.
I cannot access the drive but the light does go on	The CD may be damaged or unreadable. Try removing and reinserting the disk. Try cleaning the CD. Verify that pin #1 of the controller cable is matched to pin #1 on the drive and on the motherboard. If it never worked, verify that the jumpers on the drive are set correctly.
The drive drawer will not open	Press the button once and wait at least a minute. In Windows, go to "My Computer", right click on the CD-ROM drive and choose "Eject" from the menu. With the computer unplugged, you can open most CD-ROM drawers with a unwound paper clip. Poke it, as straight as possible, into the hole and push with moderate force (the paper clip may bend a little) to force the drawer open a half inch. Now pull the drawer the rest of the way open. If the problem persists, check that the power connector and controller cable are securely connected to the drive. A CD may be jammed or broken inside the drive. Access may require the removal of the drive's outer case. If this is necessary, it is very likely that the drive will have to be replaced.
I hear it spinning and then stopping repeatedly	The CD may be damaged or unreadable. Try removing and reinserting the disk. Try cleaning the CD. Verify that pin #1 of the controller cable is matched to pin #1 on the drive and on the motherboard. If it never worked, verify that the jumpers on the drive are set correctly.
The drive seems to transfer data too slowly	Is the drive on the same controller cable as the primary hard drive? If so, performance will be slowed because only one device can communicate at a time. Move it to the second IDE controller.

How to Replace a CD-ROM Drive

Before opening the case, unplug the PC to avoid an electrical shock hazard. Exercise caution as there are sharp edges on a PC and its components. Always wear a static electricity discharge strap and attach the lead to the metal frame of the case, when working with your PC's components to avoid damaging your PC. Note that some manufacturers will void your PC's warranty if you open the case.

Caution: Please read our safety information before attempting any testing or repairs.

Always follow the manufacturer's instructions if they deviate from our guide. Failure to do so may complicate the installation.

1. Unplug the PC
2. Open the case
3. If you are replacing a CD-ROM, disconnect the controller cable, power connector and audio connection (if present). Remove the retaining screws and remove the drive.
4. Set the jumper to "Master" or "MA" if the drive will be the first or only drive on a controller. Set the jumper to "Slave" or "SL" if it will be the second drive on a controller.
5. Insert the new drive into the bay used for the old drive, or select a bay that has a suitable corresponding opening in the case front. Make sure it is right side up (the button should be under the drawer).
6. Secure the drive in place with the provided screws or rail inserts.
7. Connect the controller cable to the drive and the motherboard (the second IDE controller is preferable). Make sure that pin #1 of the cable corresponds to pin #1 on the drive and motherboard. If you have two connectors to choose from, use the one at the end.
8. Connect the power to the drive.
9. Connect the audio wire (if one is being used) to the drive and to the sound card or motherboard.
10. Close the case.
11. Plug in the PC.

The Cooling Fans

Cooling Fan Overview

Diagnosing Fan Problems

Installing a Fan

Cooling Fan Overview

A PC generates a lot of heat and heat is a major enemy of electronics. So it is important to keep your PC running cool. Most PCs employ a combination of heat sinks and fans. All power supplies incorporate a fan. Most CPUs have a heat sink and a fan. Many PCs have another fan inside the case to circulate air and some have fans just for cooling the drives.

Because these fans have moving parts and they always run while the computer is on, they will wear out. It is not uncommon for a fan to wear out in just one year, although many run for years.

If a fan in your PC stops running, it is critical that it be replaced. Your PC will run without an operating fan, but possibly not for long. It is never wise to run the PC if there is a possibility of overheating. A system that overheats may malfunction, shut itself down or some of the components may be destroyed Fortunately, fans are inexpensive and relatively easy to replace.

While the fan in the power supply might not be replaceable, the cpu, case and drive fans are replaceable.

How to Diagnose Fan Problems

These are some symptoms that may be caused by the cooling fans. Other components may also cause these same symptoms, check the general diagnosis page for more information.
Symptom	Check Click on underlined items for further information
It makes a squealing or other loud noise	The power supply fan is failing and needs replacement. In most cases, the entire power supply must be replaced. The CPU fan is failing and needs replacement. Another cooling fan, such as a case, drive or auxiliary fan is failing and needs replacement.
The fan is slow or does not spin at all	The power supply fan is failing and needs replacement. In most cases, the entire power supply must be replaced. The CPU fan is failing and needs replacement. Another cooling fan, such as a case, drive or auxiliary fan is failing and needs replacement. Any of the fans listed above are dirty and need to be cleaned.
The PC freezes or shuts itself off unexpectedly	The system may be overheating because of inadequate cooling. Check that all cooling fans are working properly.

Installing a Fan

Caution: Please read our safety information before attempting any testing or repairs.

Before replacing any of the fans, unplug the PC to avoid an electrical shock hazard. Exercise caution as there are sharp edges on a PC and its components. Always wear a static electricity discharge strap when working with your PC's components to avoid damaging your PC.

Your PC probably has two or more fans. Common fans include a power supply fan, CPU fan, case fan and drive fan. Each of these is generally replaceable with the exception of the power supply fan. Some power supplies have replaceable fans, but many do not. If the fan is not replaceable, then you will have to replace the power supply.

Note: Cleaning your existing fan may solve your problem. The build up of dust and grime may slow or stop an otherwise working fan.

Case Fans

Case fans can be mounted to the case, in a drive bay or installed in a slot. They are easy to remove and install. If replacing a fan, simply open the case, locate the fan, disconnect it from its power source, remove any fasteners holding the fan in place and install the new fan. If you are installing a new fan, rather than replacing one, then locate a suitable position for the fan, secure the fan in place, connect it to a power source (typically one of the power connectors from the power supply or possibly a connector on the motherboard designated for powering a case fan.

Drive Fans

Drive fans typically mount in an available drive bay and connect to a power lead from the power supply. Whether installing a new fan or replacing an existing fan, open the case, locate a bay that will best move air over the drives. Secure the drive fan into the drive bay and connect it to the power supply.

Power Supply Fan

If the fan in the power supply does not spin, spins slowly or makes excessive noise, then it must be replaced. Upon inspection of the power supply you should be able to determine if the fan can be replaced. If you find no screws securing the fan and the unit appears to be held together with rivets, then you will probably have to replace the entire power supply. Do not try to replace the fan if it is not designed to be replaced. Note that the power supply may contain a capacitor holding a potentially dangerous electric charge, even when unplugged. Use caution when opening the power supply, do no touch interior components unless you discharge the capacitor first. To replace a modular a fan, remove the screws securing it in place, disconnect the power connector and remove the fan. Connect the new fan and secure it in place.

CPU Fan

CPU fans may mount to the CPU and socket on the motherboard, may fasten to a fan mount or fasten to the case and channel air flow to the CPU with a shroud. Replacement of the case or specialized fan is fairly easy. Disconnect the power connector, remove the screws or clips securing the fan in place and install the new fan.

CPU fans that mount directly to the CPU can be trickier to install. Use of excessive force, slippage of tools, misalignment of fan can result in damage to the CPU, motherboard or both. First of all, avoid touching the bottom of heat sink attached to the fan. Skin oil and dirt will reduce the effectiveness of the fan and heat sink. Clean the bottom of the heat sink with an alcohol swab and let it dry before installation. Apply a small amount of thermal grease to the bottom of the heat sink and spread it with a gloved fingertip. Orient the fan so that the spring latch aligns with the tabs on the CPU socket (note the small tabs on the left and right side of the socket in the photo below)

Align the heat sink so that the smaller side of the spring latch aligns with one of the tabs on the CPU socket. Now check that the power connector can reach the CPU power connector on the motherboard. Now lower the spring latch and hook it under the tab on the socket. Set the heat sink/fan unto the CPU and carefully pull the spring latch down to hook onto the tab on the other side of the socket. If you use a tool, such as a screwdriver, to push the latch down, you risk it slipping off and damaging the motherboard. If you have difficulty, try using the eraser end of a pencil to push on the part of the latch inside the fan housing while pulling the spring latch with you other hand. It can be challenging; take your time or you may destroy the CPU or motherboard.