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Power supply failures
Power supply failures
A procedure to identify and troubleshoot the power supply failure based
on the most common symptoms:|
- Uncommanded hard drive recalibrations
- Windows Event Log data (Event ID 9 from "atapi")
- Low overall performance
Symptom I - Unexpected HDD restart
The hard drive may shut down and restart on its own with a typical spin-down-click-spin-up sound (readily identifiable once you hear it). The machine will freeze for a short while (about up to ten seconds until the disk restarts). Once the drive is back online, normal operation will be resumed in most cases (barring possible network communication loss and reconnection caused by the timeout).
Symptom II - "The device ... did not respond ..." in the Event Log
The analysis of the System Event Log may yield some additional
information. The Event Viewer is available via "Start" -- "Control
Panel" -- "Administrative Tools" -- "Event Viewer"; once there, open the
"System" log. The log may contain multiple entries similar to the
|| The device, \Ide\IdePort0, did
not respond within the timeout period
Note that port numbers depend on the system configuration.
Symptom III - Drives in PIO mode, high CPU load
The hard drives may fall back to the legacy PIO (Programmed
Input/Output) access mode. PIO mode is fairly slow and imposes an
excessive processor load. Evident symptoms include|
- Overall performance low.
- System response "jerky", even for a simplistic tasks.
- Video playback is not possible (frame rates low, down to less
than one frame per second in extreme cases)
To verify the drive mode,
- Open the Device Manager (right click "My Computer", select
"Manage", then navigate to "Device Manager").
- On the right-hand panel, double click "Primary IDE channel"
under "IDE ATA/ATAPI controllers".
- In the window appeared, switch to the "Advanced Settings" tab.
This yields a window similar to the screenshot below.
- Make sure "Transfer Mode" is set to "DMA if available" on both
- "Current Transfer Mode" should read "Ultra DMA Mode X" for all
the installed devices. Hard drives are typically running in UDMA 4
or UDMA 5, CD and DVD drives typically use UDMA 2.
- Repeat steps 2-5 for the "Secondary IDE channel" if available.
IDE drives in PIO mode
"PIO Mode" readout (as illustrated above) indicates
that drives cannot reliably communicate with the controller using DMA
modes. The system detects communication problem and degrades drives to
- If one of the above symptoms exists, check the other two.
- If positive on all three, consider replacing the power supply
unit (PSU). You may want to temporarily install a known-working PSU
from the other system to see if it rectifies the problem.
- Once the power supply unit is replaced, open the Device Manager
and uninstall all the disk drives and IDE controllers, then reboot.
Windows does not switch back to UDMA mode unless the affected
devices are re-detected and re-installed.
- Run CHKDSK on the affected volumes to take care of any possible
problems caused by transient drive failures.