Service manual

F.1 Software Rev Update using E-Mail
The disk for the New438/420T is specifically bootable on the New438/420T.
This boot software is not normally visible and cannot be copied from one
disk to another. The entire disk must be ‘disk copied’ or ‘copy disked’.
The application software (‘GBR420.exe’) is visible and can be copied to
and from an e-mail, another disk or from the hard disk of a computer. It
only operates in a New438/420T boot-disk.
PROCESS:
1. Attached to the New438/420T is a new revision ‘GBR420.exe’. Save
this and any other files to your hard disk in a unique folder (such as:
\gbr\26412011\ where 26412 is the part number and 011 is the current
revision number).
2. Make a disk copy of your current master. In Windows Explorer or My
Computer, right click on the 3 ½” Floppy A: and Copy disk…your current
master to a new 3 ½” disk.
3. Copy the new e-mailed software revision executable, GBR420.exe to
the new disk from step 2. Overwrite the previous revision. Copy any other
files sent, such as the dictionary (msgs420.dat) to the appropriate place on
the new disk (such as: \gbr\msgs420.dat). This is the new master for the
new revision.
4. Make a disk copy of this new master to another 3 ½” disk. Use this
copy as the machine boot-disk.
File Structure on the floppy:
A:\gbr
gbr420.ini [Hardware/Application Initialization]
msgs420.dat [Application Screen Text Dictionary, English]
a:\gbr420.exe [Application]
a:\diskmon.bin [Boot Monitor]
F.2 GBR OMR Reader Set-up
Reader Pre-Amp:
1. Adjust Focus (Ensure beam after focus sees a minimum of 4 dots of
code)
2. Potentiometer on Pre-amp until 9 of 10 LED’s are lit. (On white paper)
3. Move paper to a Black Line, should have 3 or 4 LED’s lit.
Reader Board:
1. 2 Potentiometer L (low level) & G (high level)
L (low level) should be set to .6v to .8v.
B. G (high level) should be set to 3.9v to 4.1v.
Low Level should be reading on blank white paper.
High Level should be reading on black line.
Dots should read 2.4v to 2.6v (approx.).
Note: It is very important while setting up voltages to continue to monitor
Bars on Pre-Amp Board (setting voltages sometimes will change numbers of
bars). Also ensure that you do not max out potentiometers while adjusting
voltages.
MISCELLANEOUS
420T V6LT OPERATOR & SERVICE MANUAL ISSUE 2009/06 Rev. 6/21/2011 SECTION F – PAGE 135
071-33370-400