Hardware Reference
In-Depth Information
scratch using a disk editor utility or hire a data recovery specialist who can do this for
you. If you don't need to recover the data on the drive, simply reinstall the OS from
scratch, which will prompt you through partitioning and formatting the drive.
•
The MBR is corrupt
—Torepair this,
cold boot
(poweroff,then on)fromaWindows
XP or later install disc and use the FixBOOT command in the Recovery Console (XP)
or Recovery Environment (Vista or later), which rewrites the MBR.
The system is experiencing intermittent memory errors
If the memory was recently added or some other change was made to the system, you
should undo that addition/change to see whether it is the cause. If it's not, remove and re-
seat all memory modules. If the contacts look corroded, clean them with contact cleaner
and then apply contact enhancer for protection. Check the memory settings in the BIOS
Setup; generally, all settings should be on automatic. Next, upgrade to the latest BIOS for
your motherboard, and remove all memory except one bank. Then run only one bank of
memory, but in the second or third bank position. A socket can develop a problem, and
most motherboards do not require that the sockets be filled in numerical order. Also, re-
place the remaining module with one of the others that was removed, a new module, or a
known-good spare.
If you get this far, the problem is most likely either the motherboard or the power sup-
ply—or possibly some other component in the system. Remove other components from
the system to see whether they are causing problems. Reseat the CPU, and replace the
power supply with a high-quality new unit or a known-good spare. Finally, try replacing
the motherboard.
The system locks up frequently and sometimes reboots on its own
This is one of the classic symptoms of a power supply problem. The power supply is de-
signed to send a special Power_Good signal to the motherboard when it has passed its
own internal tests and outputs are stable. If this signal is dropped, even for an instant, the
system resets. Problems with the power good circuit cause lockups and spontaneous re-
booting. This can also be caused if the power at the wall outlet is not correct. Verify the
power supply output with a digital multimeter—all outputs should be within 5% of the
ratedvoltages.Useatesterforthewalloutlettoensurethatitisproperlywired,andverify
that the voltage is near 120V. Replace the power cord or power strip between the power
supply and wall outlet.
Unfortunately, the intermittent nature makes this problem hard to solve. If the problem
is not with the wall outlet power, the best recourse is to replace the power supply with
a high-quality new unit or a known-good spare of sufficient rating to handle the system
(300 watts or higher recommended). If this doesn't help, reseat the CPU and reinstall the
