Subtests; Why Run A Diskette Drives Test; Serial/Infrared Ports Test Group - Dell PowerEdge 4200 Installation And Troubleshooting Manual

Subtests

The four diskette drive subtests in the Diskette Drives
Test Group and the drive functions they test follow:
•
Change Line Test
Checks for bent pins on the diskette drive controller
and for defective lines on the diskette cable
•
Seek Test
Checks the drive's ability to search for a specified
track on the diskette and to position its read/write
heads to all tracks
•
Read Test
Positions the read/write heads at each cylinder of the
diskette for reading data and verifies that all tracks
on the diskette can be read correctly
•
Write Test
Positions the read/write heads at each cylinder of the
diskette and verifies that all tracks on the diskette
can be written to correctly

Why Run a Diskette Drives Test?

Very often, a diskette drive problem may first appear to
be a diskette problem. A box of defective diskettes might
produce faulty-drive error messages. The test results can
be confusing, so Dell suggests running the subtests in the
Diskette Drives Test Group more than once using dis-
kettes from different sources.
A command that is typed in an incorrect form (usually
called a syntax error) is another possible cause of diskette
drive problems. Be sure you have entered the command
in the proper form.
If the diskette(s) and command syntax are eliminated as
causes, the following symptoms usually suggest a drive
problem and warrant running a subtest in the Diskette
Drives Test Group:
•
An error message appears on the screen stating that
the computer cannot read from or write to a diskette.
•
A diskette cannot be properly formatted, or format
error messages appear on the screen.
•
Data on diskettes is corrupted or lost; these problems
may be intermittent.
S
erial/Infrared Ports Test Group
The subtests in the Serial/Infrared Ports Test Group
check the computer's interface with external devices,
such as a printer and a mouse, that are connected to the
computer through a serial or infrared port. The subtests in
this test group are not intended as a diagnostic test for the
actual peripheral attached to each port.
NOTES: With certain modems installed, the subtests in
the Serial/Infrared Ports Test Group may fail because the
modem appears to the diagnostics as a serial or infrared
port, but it cannot be tested as a serial or infrared port. If
a modem is installed and one of the subtests in the Serial/
Infrared Ports Test Group fails, remove the modem and
run the diagnostic tests again.
If an external loopback connector is not attached to a
serial or infrared port, the Serial External Transmission
Test will fail for that port and the results of this test
should be ignored. An external modem connected to the
port does not substitute for an external loopback
connector.
Subtests
The four subtests in the Serial/Infrared Ports Test Group
and the port functions they test follow:
•
Serial/Infrared Baud Rate Test
Checks the baud rate generator in each serial com-
munications chip against the computer's clock
•
Serial/Infrared Interrupt Test
Checks the serial port's ability to send IRQs to the
microprocessor
•
Serial/Infrared Internal Transmission Test
Checks several internal functions of the serial port
using the internal loopback mode of the serial com-
munications chip
•
Serial External Transmission Test
If a loopback device is attached, checks the line con-
trol bits of the serial port and sends a test pattern at
several baud rates, checking the returned values
Running the System Diagnostics 5-15