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A.
Command Screen not Displayed - POSSIBLE CAUSES
1.
Test is being run in a multi-user operating system.
2.
Incorrect power is being supplied to the drive or interface card.
See Appendix A.
3.
Loose or bad power or data cabling.
4.
Bad controller board (replace first).
5.
Bad interface board (replace second).
6.
Bad Winchester drive (replace third).
There are a number of conditions to be met before the TSTW command screen will be
displayed.
The test program will look for a ready drive.
The drive must be up to the
correct operating speed before it will become ready.
Check the cables going to the drive.
Make sure both the power connections and the data connections are tight.
When the system is powered up, listen to the drive motor.
You should hear the platter
coming up to correct speed.
The drive may be bad if the platter is not turning with
correct power going to the drive.
On the 8" Winchesters make sure that the platter and
the head actuat or are unlocked.
The drive must present a ready signal to the controller bordo
This signal must be sent to
the controller board by the interface board.
A bad interface card or bad data cable would
keep this signal from being transferred.
The second condition that needs to be met to enter the command screen mode is a selected
drive.
A problem in this area could be due to a fault on the logic card on the drive, or a
bad interface or controller board.
B.
Errors Devdoped In Running 'VERIFY HDR' Command
Error Interpretation
The most common errors developed by the VERIFY HDR command are ECC type of
errors.
ECC stands for error correctlng code, which is used on the Winchester controller
board to locate and possibly correct bad data in the sector.
If the error is larger than 8
bits, then the operating system will report the error to the user as a Read error.
The
test program will flag these errors as Uncorrectable ECC Errors.
Depending on the
number of errors reported, various repair methods are available.
A small quantity of errors can possibly be repaired by using the test program.
The
procedure is to first write down the bad locations found by the VERIFY HDR command
on a sheet of paper.
The errors can be viewed by typing ERROR while at the command
screen.
The first error will be displayed.
The next error can be viewed by typing <cr>.
Continue to type <cr> until all of the error s are viewed, then type cr to return to the
command screen.
Go to the first location by using the HEAD, CYLINDER and SECTOR
commands.
Read the sector into the buffer by typing READ.
The error counter should
increment.
Write the data back out to the sector by typing WRITE.
Read the location
again.
If the error counter does not increment, then the header is now correct and the
ECC agrees with the data in the sector.
Repeat the procedure for all of the bad
locations.
When completed, clear the error butter with, the command ERROR CLEAR.
Rerun the VERIFY HDR command.
The error counter should now report 0 errors.
If
any of the errors return, the error cannot be repaired and must be locked out by either
the FMTW program or the WALT program located on the operating system disk.
IMS International
8000 Hardware Manual/7.01.83;Page 119
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