The most common problem with any new PC build is partially made or
improper connections. Most of the troubleshooting procedures in this
blog require that the cover be removed form the PC and that some
components be removed or reconnected. For this reason, it's best to
plug in the PC through a switched power strip, so you can use the power
strip switch to isolate the system from the electrical supply before
every repair attempt.
Most people, even professional technicians, tend to get a little sloppy
when troubleshooting, often accidentally introducing a new problem to
replace the old. The main key to any type of troubleshooting is to go
one step at a time. That way, when the original problem is corrected,
you'll know exactly what did the trick, and if you create a new
problem, you'll know what went wrong.
We will address five basic scenarios in this blog, ranging from a stone
dead system to a lack of functionality, such as a modem that won't
connect. Although these procedures will uncover most assembly errors,
there is often no way to isolate a dead component without having other
known good parts to swap out. In the world of professional PC
troubleshooting and repair, the "swap' till you drop" strategy is still
the most common troubleshooting technique employed. Swapping
components requires no expensive diagnostics software or hardware and
is usually the quickest way to isolate a problem. Another reason to
steer clear of specialized diagnostics tools is that they are geared to
identifying problems with subcomponents that can't be fixed anyway.
Finding out exactly which address is bad in the system RAM or in the
cache memory of a drive or motherboard is of little use when you'll
have to replace the whole assembly anyway.
These troubleshooting procedures are for a newly built PC. If you have
been using the PC for some time for any new problem that arises you
have to consider the possibility of a computer virus. One way to check
whether you have a hardware problem or a virus problem at boot time is
to boot from your original operating system CD. If you do contract a
virus, there are many virus doctor programs you can buy with a
reasonable certainty they will fix the problem, but you may need
Internet access to download the latest virus inoculations form the
manufacturer's Web site.
In general, if you computer a serious recurring software problem with
your PC, and you has good backups of any important data, the most
reliable fix is to wipe clean the hard drive by deleting the primary
partition with the FDISK program and reinstall the software form
scratch. Just be really sure you have the original CDs and serial
numbers for all the software you use, in addition to good data backups,
because once you FDISK, it's all gone. Before running FDISK, confirm
that your operating system CD will boot!
Caution: We cannot reiterate enough times that you should disconnect
power from the system before making any change inside the case; then
reconnect after each change to check the result. If you smell a burnt
electronics odor at any time, you have a blown component and should not
attempt powering up again until it is found and replaced and the
cause of the failure is determined.
Stone DeadYou switch on your new system and there are no signs of life. The power supply fan doesn't turn; there are no sounds, no lights.
· Make sure the power cord is fully inserted into the power supply, the
override switch on the back of the supply (if so equipped) is turned
on, and the voltage switch is set correctly. Don't neglect to make
sure the wall socket you are plugged into is live by unplugging the
computer and plugging a radio or lamp to check.
· Recheck the motherboard documentation for the proper connection of
the leads from the front panel power switch. Don't settle for just
looking at the switch connection to the motherboard; remove the lead,
check that the terminal block matches the documentation, and then
reconnect it. Undo the main power supply connection to the motherboard
(this requires pressing in the clasp as you pull gently on the
connector), inspect the connector for damage, and reconnect. On Pentium
4 systems make sure you have connected the additional 12V header.
· Search for shorted components by disconnecting the power cables and
ribbon cables from the drives; one drive at a time, retrying power up
after each drive is disconnected. Without reconnecting the drives,
remove each adapter card (leave video for last) one at a time, retrying
power up after each removal.
· Remove and reinstall memory DIMMs or RIMMs, inspecting for physical
damage. Remove and reinstall the heatsink and CPU, double checking the
CPU fan is connected to the proper terminal on the motherboard. Never
attempt to power up the system without the heatsink installed.
· In extremely rare cases, the power switch on the front panel may be
faulty. You can use a continuity else that could cause a short circuit
to the motherboard circuitry. Reinstall the motherboard in the case
and reinstall the video adapter, then try powering up.
If you still have no power, the problem is most likely a defective power supply or motherboard.
Power Comes On; Screen Is DeadYou hear the power come on and the drives spinning up, but the screen remains blank.
· Make sure the monitor is plugged into a good power outlet by
switching wall sockets with the power supply cord. If the power cord is
not permanently attached to the monitor, make sure it is fully
inserted in the socket on the back of the monitor. If your monitor is
equipped with manual dials for brightness and contrast, make sure they
are in the middle of their range.
· Remove the monitor connector form the video card and check that none
of the pins in the shell are bent over. Note that some missing pins in
the three-row high-density connector are normal.
· Remove and reseat the video adapter, making sure the hold down screw
doesn't cause the back end of the adapter to lift partially out of the
bus slot.
· Check for a defective or conflicting adapter on the bus. Remove any
other adapters installed, one by one, rechecking power after each.
Don’t forget to unplug the power supply, or turn off the power strip or
override switch before each removal.
· Double-check the motherboard documentation for overlooked CPU
selection switches or jumpers settings. Depending on the motherboard
used, CPU selection might be automatic. Don’t take the manual at its
word that default settings are set; check the actual switch and jumper
positions on the motherboard.
· Double-check that CPU and memory modules are seated properly,
particularly slot-type CPUs, which can take a good deal of pressure to
mate correctly with the motherboard.
If you still have no live screen, the problem is likely defective
hardware. Make sure the case speaker is properly connected to the
motherboard as per the motherboard documentation. If you hear a series
of beeps, note the number and sequence, s they will pinpoint the
defective component. The motherboard documentation or manufacturer Web
site should give the codes, although the most likely candidate for
beeps on a dead screen is the video adapter. If no beeps sound, the
most likely candidates are a dead monitor (easily checked by connecting
it to another system), a defective motherboard, or a defective power
supply. In some instances, you may have bad RAM or a bad video adapter
but still not hear any beep codes.
Screen Comes On; No BootYou get text appearing onscreen, but the PC either won’t try to boot or locks up in the process.
No onscreen messages indicating boot failure.
Enter CMOS Setup by following onscreen instructions (usually by
pressing the DEL or F1 key) after power up. Select the CMOS option to
Restore Default Settings or similarly phrased option, save and reboot.
Note: If you cannot access Setup, double-check that the keyboard and
mouse connectors aren’t interchanged. If you still can’t access Setup,
disconnect power and remover all adapters except the video and
disconnect the drives. If you still can’t access Setup, you have some
defective hardware, most likely the motherboard, although it could
still be the RAM or CPU. These core components should always be bought
from the same source to simplify return issues.
If there are still no messages indicating boot failure, enter CMOS
Setup again and make sure the CPU speed setting, bus clock frequency,
and IDE interface speed don’t exceed your component ratings.
If the system hangs at Verifying DMI Data Pool, it is usually a
motherboard or IDE device problem. If you have an option to enable
Reset Configuration Data, use it. Disconnect your IDE cables from the
motherboard and see if you can get as far as a Drive Failure or No Boot
Device message. If not, the motherboard will probably need replacing,
although you can try discharging the onboard battery first by using
the jumper setting in the motherboard manual for disabling a forgotten
password.
Missing operating system or no boot device message.·
Check that the IDE cables are connected to the drives and motherboard
properly by removing and reinstalling them. Make sure the power
connectors to all the drives are properly installed. Make sure the
master / slave jumpers for the drives are installed properly.
· If the system tries to boot a CD and fails, it may just be bad
timing. Strangely enough, some high-speed CD drives take so long to get
up to speed that the BIOS (motherboard logic) gives up on them before
they get there. If the screen displays a message such as “Insert CD
and hit any key when ready,” eject the CD tray; then push it back in,
but wait until you hear the drive spin up before pressing a key to
continue. It might take a few efforts to get this right if it’s going
to work.
· Check that the operating system CD is readable in another system, and
don’t try using pirated operating system software on home recorded
CDs.
· Enter CMOS Setup and rearrange the boot sequence so that the CD-ROM
or the IDE channel to which it is connected is selected as the first
boot device. This shouldn’t be necessary, but it will help if a
previous attempt to install the operating system failed, leaving the
hard drive appearing bootable to the motherboard.
· Simplify the system by removing any additional drives so all you have
left are a “master” hard drive on the primary IDE channel. If it
doesn’t work, as a final check try both drives on the primary
controller with the CD as the “slave.”
Boots; Locks Up During Or After OS InstallEverything
appears to be working fine, right up through formatting the hard
drive. But, at some point during the operating system installation or
immediately after, the PC locks up.
First check with your parts vendor or operating system manufacturer for
known compatibility issues. Also be aware that some CDRs and
combination drives have problems with operating system install, which
usually manifests itself as a “read error”.
Unplug the power and remove all adapters except the video adapter.
Install the operating system. Next install the motherboard drivers from
the CD that shipped with the motherboard and the video adapter driver
from its own CD. Install any other adapters one at a time, reconnect
power and reboot, allowing the operating system to deal with them
individually.
Make sure you are using the approved cabling for any high-performance
parts such as 80-conductor ribbon cables with Ultra 66 or Ultra 100
hard drives, because communication breakdowns at high speeds are likely
to show up under the load of operating system installation.
In some rare cases, operating system installation can fail repeatedly
because a borderline component is suffering a heat-related failure as
the system warms up. This is extremely difficult to troubleshoot
without parts to swap out, and if you bring the parts back to the point
of purchase, it might be hard to convince the vendor that the problem
isn’t in your imagination. Make sure the CPU heatsink is properly
installed, the heatsink fan is working, and you aren’t building the
system in a hot attic in the summer. Go through the steps related to
CMOS Setup in scenario 3 and document all the troubleshooting steps you
go through for the vendor. Try reinstalling the operating system
several times with no adapter other than video before concluding that
you have a hardware failure.
Boots and Runs
If you operating system installation goes smoothly but you have trouble
accessing a particular device, the problem is as likely to be
software as hardware. Extensive software troubleshooting is outside
the scope of this website, but we will mention some of the key points
you can check in Windows operating systems.
Hard Drive
· Any message indicating a hard drive read or write failure is a
hardware error. Try replacing the ribbon cable, making sure you use the
newer 80-conductor type.
· Isolate the hard drive on its own IDE channel, moving any other
drives to the secondary channel on their own cable or temporarily
disconnecting them.
· If the hard drive is excessively noisy or makes a continual clunking
sound, it has suffered internal damage and odds are even an expensive
data recovery outfit won’t be able to help
CD or DVD Drive
If the drive has trouble reading a particular disc, try wiping off any
fingerprints with a clean flannel shirt. Note rewriteable discs
written in CDRs and DVDRs are often unreadable in other drives.
For continual read errors, try all the steps for hard drive
troubleshooting new IDE cable, isolation, and swapping IDE hard drives,
so isolating them on their own controller will often fix the problem.
If you can’t play music CDs even though your speakers work with other
computer sounds, the thin audio cable from the sound card (or
motherboard with integrated sound) to the four-pin connector on the
back of the drive is improperly installed or missing.
If you record music CDs on our PC and they won’t in your stereo, make sure you are using CDR blanks, not CDRW.
If you have a CDR or DVDR and your write sessions often fail, try
recording at a lower speed and make sure you are using media certified
for at least the speed at which you are recording.
