Ask Me Solution

With thousands of devices that work with Windows operating systems, it is practically impossible to describe all scenario specific solutions. What remains is to describe a strategy that will help you identify and resolve the problem.

The first step is to determine that the problem is really a hardware conflict at the OS level and not something caused by an incorrect physical installation. If you are able to normally boot into the OS, this would probably mean that the physical installation is fine. However, you cannot be certain at this stage. Try accessing the device. If the system hangs, crashes or starts acting weird, then it is pretty safe to assume that the physical installation is fine and the problem is because of the operating system’s interaction with the device. However, just to be on the safe side, power off and inspect the device for proper installation.

If everything seems correct, verify that you have followed the installation procedure as described in the manufacturer’s manual, have all the required software driver CDs and/or floppies on hand and switch the PC on.

If the device drivers are already installed and you are facing system instability when accessing or using the device, go to the Using the Device Manager section.

A wide range of problems may be causing the above and other symptoms. Assuming that the hardware is not defective and has been installed correctly, at the operating system level the problems can be broadly classified as follows:

• There could be a resource allocation (IRQ/memory address) conflict. Two devices are allocated the same IRQ/memory address space.Usually, non-Plug and Play devices would give this problem. Since Windows is unable to detect these devices it may not allocate the resources properly and hence cause conflicts with an existing device.

Note: Some devices, such as PCI devices, can share a single IRQ without conflicts in Windows 2000/XP.

• The software device drivers may not be compatible with the operating system, or may have been corrupted, or may not have been installed. If you have recently upgraded from Windows 95/98, this would usually be the problem.
• A new software program installed is trying to use system resources allocated to other hardware devices or software programs.

A hardware conflict may occur when you add a new device to your system. In some instances, this conflict will not cause any problem, and depending on the operating system you may not even be aware that such a conflict exists. Typical symptoms of hardware conflicts include:

• The operating system may freeze frequently
• The new device may suffer performance problems
• An existing device that is conflicting with the new device may suffer performance problems
• Windows starts in Safe Mode
• The system crashes and you get a BSOD (Blue Screen of Death)
• The sound card stops working or stutters
• The screen jumps and shows garbled images
• The mouse stops working
• Modem/network card doesn’t respond
• CD/DVD drive doesn’t respond or crashes the system

Hardware devices can conflict with each other due to a variety of reasons. Every hardware device installed must be allocated a set of operating system (Windows) resources to operate correctly. These resources include IRQ, DMA (Direct Memory Access), I/O port addresses and memory resources. Some of these resources will be shared by more than one device while others cannot. This depends on the capabilities of the hardware and its software drivers.

Each device installed will have one or more software device drivers that enable the operating system to access and use the device. The software could be provided either by Microsoft itself that will enable basic functionality, or by the device vendor who knows more about the specific model and hence will be able to provide a more tightly integrated device driver.

Normally, Windows Plug and Play will automatically detect the newly-added hardware, determine the system resources required and assign them properly. Plug and Play will also search for the required software drivers and install them transparently. If Plug and Play cannot find the required drivers, it will prompt the user to provide them by inserting the CD/floppy provided by the device manufacturer. Additionally, it will also reconfigure the system resources if required, for example when the newly added device requires some resources already in use.

1.Overheating of CPU
This could be due to overheating of the CPU caused by poor contact between the heat sink and the CPU. Remove the heat sink and fan (make sure the fan is working). On the exposed CPU die surface apply some thermal grease or thermal tape. This is to fill in the microscopic gaps that may exist between the CPU and the heat sink. Don’t use too much grease and don’t try to substitute with something else, use approved thermal media only. Also, don’t get impatient and try to force the heat sink on the die to try and make it fit. You may break the heat sink or worse still damage the CPU. If the fan is not working, verify the power connections. If the connections are correct and the fan still does not work you can try replacing the fan but the best option is to get a new heat sink unit (heat sink + fan). Note: The problem with a failed heat sink is the likelihood that you have already cooked your CPU. Most modern CPUs overheat very quickly and require cooling right from power on.

1. This may be a problem with the RAM modules or other add-on cards.

In case of RAM module problems, you will usually be alerted by beeps from the BIOS. Strip the PC down to the ‘barebones’, that is, just the power supply, motherboard (with CPU & heat sink), minimum RAM and display card. Switch the RAM module to another slot. Verify that the RAM modules are as per the specs defined by motherboard manufacturer. Use matched RAM modules from the same manufacturer. Try a different RAM. If everything is working you should boot up and see the message ‘No boot device’ or something similar. Power off, connect the hard disk and reboot. If the problem still occurs, this points to something wrong with the hard disk or the basic boot up of the operating system. Check the storage section and the Windows troubleshooting section of this site.

If the OS boots normally, then power off and start adding each add-on card one by one, powering up after adding each card until you isolate the culprit. Check the relevant sections for troubleshooting hints for those components.

2. It may be a BIOS problem.
Check the BIOS section in this site.

It’s pretty difficult to tell by visual inspection if slot CPUs are seated properly. When in doubt, reseat the CPU, which is fairly easy since the heat sink and the CPU are an integrated unit. Also, make sure that you correctly identify release levers located on the top of the slot CPU package.

The PC freezes or reboots suddenly

1. This could indicate a failing PSU that is not supplying power
correctly to the motherboard. You may be able to get the PSU
serviced but in most cases you will be better off getting a new
power supply.

2. This could be due to overheating of the PSU or CPU: If the PSU is
overheating, the metal cabinet may be hot to touch or you might
get a shock. Shut off immediately. Check if the PSU fan is working,
clean or replace the fan if not working or spinning very slowly.
If it’s a faulty PSU you may be able to service it.
If the PSU seems normal it might be due to an overheating CPU.

The PC powers on after the second or third try

The mostly likely problem is that the power_ok (or power_good) signal
is sent before the power supply has stabilised. Get a better quality
PSU. In modern PCs, the power switch is a logic device that tells
the PSU to supply full power to the motherboard. The power_ok signal
tells the motherboard that the power supply is available and
stable. If the signal is sent too soon the motherboard does not recognize
it and stays off to protect itself. This can happen in lowerquality
PSUs. Booting more than once is not recommended, and
you will be better off getting a better PSU.

The PC powers on but nothing happens after that (no beep)

1. This may be due to the addition of new hardware that is overtaxing
the power supply. Remove the last hardware component
installed and check again.
2. A defective hard disk or one that is not plugged in correctly:
Check the power cable to the hard disk. Sometimes it may not be
fully plugged in. Check the hard disk on another system.

The PC powers on, beeps and stops. No Power On SelfTest (POST) messages.

This may be a motherboard problem and not related to the PSU.
Check the motherboard section of this site.

The PC powers on and runs POST but there is no display

This may be a display card problem and not related to the PSU.
Check the display section of this site.

There is a squealing/whistling/whining noise when the PC starts

This could indicate either a problem with the fan, which has accumulated dirt over time, or one of the internal components of the PSU. Switch on the PC and listen carefully to confirm that it’s the
PSU fan and not the CPU fan or the hard disk. Usually, the noise will stop once the fan picks up speed, and you can ignore it temporarily.
It’s a good idea, however, to clean out the dirt around the PSU fan using a PC vacuum. This will increase the working life of the PSU fan as well as the PSU itself. If the fan stops working, the
PSU will generate heat and cause more trouble. So a little prevention will save you a lot of headaches later.

If the sound is not from the fan but from within the PSU itself, then you may be able to service it. A PSU has no ‘user-serviceable’ parts, and it’s best left to a competent technician, although in most cases of component failure, you will have to replace the PSU.

1. No power from the wall socket: Use a live power outlet. In rare
cases, the power cable may be defective and may require replacement.
Check the power cable on another working PC. Plug in a
lamp or any other electric device to see if you have a live outlet.

2. Incorrect voltage setting on the PSU: Select the proper voltage
setting (220-240V) on the back of the PSU. WARNING: If you have
switched on the PC with the voltage set to 110-120V and with a
mains supply of 240V you may have blown your PSU beyond
repair at worst or blown a fuse at best. Be careful!

3. The front panel power switch’s connector to the motherboard
is not fixed correctly or has come off or is defective: Check the
motherboard manual and fix the lead (wires) from the front
panel switch to the motherboard correctly. If there is still no
power, try a different lead.

4. The front panel power switch is defective: Replace the switch.
In case you do not want to get a replacement, one option is to use
the reset button. The only problem with this is that to cut the
power to the system in case of system hangs etc., you will have to
switch off the power from the mains wall outlet rather than
from the front panel.

5. The power supply connections to the motherboard are not correct:
Check the power connections from the PSU to the motherboard.
Refer to the motherboard manual and identify the correct
connection points.

6. Not identified; non-PSU related problem: After attempting all
the above, if the system still doesn’t power up, it is time to look
elsewhere.

Disconnect all the drives and see if it is powering up. (Note: Pull
out the power cord when removing or disconnecting
something.)

If the system is powering up, then start reconnecting the drives
one by one to identify which is defective drive.

If the system is not powering with all drives disconnected,
remove the other adaptors one at a time and checking to see if it
is powering up. Leave the video adaptor for the last.

If you are able to isolate the problem to one of the adaptor cards,
verify that the slot and the adaptor cards are compatible. Then
try plugging it into a different slot and see if the system powers
up before discarding it and going for a new one.

If the system is still not powering up, then you either have a
defective PSU or a defective motherboard. If there is a burnt
smell, then most probably either one of them has been fried.
Look for burn marks on the motherboard. Sometimes the PSU
and motherboard may be incompatible. If the motherboard looks
fine, replace the PSU, since it’s cheaper!

Check the relevant sections of this guide for troubleshooting
hints for the other components.

Among all the PC components, the power supply is the most dangerous.
It converts the 240V wall voltage into smaller 12V, 5V and
3.3V DC allocations required by the PC. Usually, the power supply
comes with the cabinet and is backed
by a warranty so you shouldn’t have
problems. However, it pays to be careful
and take the extra effort to verify
the quality of the power supply. If you
are purchasing it separately, opt for a
brand name. Check around with your
friends, the Internet and other system
builders. Horror stories of faulty PSUs
that blow up and ruin entire PCs are common, so be careful. A good quality PSU will not only give your system a long life span, it will
also help reduce the noise and heat generated inside the cabinet.