45
media removal, or in the event of a write error during recording. When selected from the setup
menu, the repair utility will scan the drive for problems, report the number of errors and correct the
errors. Recovered fi les are placed in a
RECOVERED
directory that is generated in the
SOUNDDEV
folder.
Specifi c operations include:
1.
Boot Record Check
– the volume’s boot record is checked for proper information. Any out-of-range
values are forced to the nearest valid value.
2.
FAT Chain Scan
– each fi le on the drive is allocated space by linking together data clusters into a
“chain” of clusters. Each chain is specifi ed in the drive’s fi le allocation table (FAT). In this stage of media
repair, each and every FAT chain is scanned and checked for validity. Broken chains, lost chains, cross-
linked chains, and chains with no end, are fi xed or truncated.
3.
Lost Chain Recovery
– FAT chains that are not tied to a fi le are considered “lost.” These chains rep-
resent used space on the drive, and may have been separated from their fi le due to a drive error or
improper shut-down. These chains are converted to fi les and placed in the “RECOVERED” folder.
4.
RIFF (WAV/BWF) fi le check
– All RIFF fi les are checked for proper format. RIFF fi les are composed of
“chunks” of data, where each chunk has a type and a size. If the size does not match the actual amount
of data for the particular chunk (which might be the case if the fi le was not closed properly), the size is
adjusted.
At the end of the repair operation, the number of errors found and fi xed is displayed. In some cases,
errors can not be fi xed automatically.
Also, it’s possible that the drive is corrupted in such a way the media repair utility is unable to con-
tinue. In this case the operation will abort and the user is prompted to check the hardware and try
again.
Drive Type
The 744T ships with a 2.5-inch ATA-5 interface, 5400 RPM hard drive. Sound Devices has chosen the
specifi c mechanism for maximum vibration and shock resistance. Most 2.5 inch drives conforming to
the ATA specifi cation can be substituted for the factory hard drive. When choosing a substitute hard
drive, note that higher RPM hard drives draw more current, reducing battery run time. Higher speed
drives may be used with the 744T, however they will not signifi cantly improve performance. They
will slightly increase transfer throughput with the penalty of increased current draw and reduced
battery run time. The 744T can address drives with capacities up to 2 TB.
Drive Replacement
The internal hard drive can be removed and replaced if the device fails or if a different capacity drive
is needed. The internal hard drive is not intended to be a swappable, deliverable medium. Its multi-
pin connector is not rated for repeated insertion and removal cycles and may be prone to breakage
with repeated cycling.
In typical service conditions Sound Devices recommends hard drive replacement once every three years.
The hard drive is mounted to the bottom-side of the recorder’s chassis and is screwdriver acces-
sible. The drive is “suspended” in the unit with a shock isolating membrane and is attached to the
main circuit board via a “fl ex board”. Since the unit’s high-density circuitry and tight construction
require specifi c electronics knowledge, Sound Devices strongly recommends drive replacement be
performed by a qualifi ed technician using proper ESD precautions. Drive replacement done by a
qualifi ed technician has no warranty implications.
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