Document Number 2000
Logitech Scanner Standard Diagnostics
4/15/92
                       
The following diagnostics should help determine most problems you might
encounter when installing/using Logitech scanners.

Generally, there are two sources of possible conflicts which will affect the
operation of your scanner: hardware conflicts and software conflicts.  Either
conflict could cause the scanner, or even the system, to work abnormally.

To find out if there is a hardware conflict existing in the system, find
out pertinent hardware information (IRQ, DMA, I/O ADDRESS) about the scanner
and the other hardware peripherals connected to the system, such as mice, 
modems, printers, fax boards, network cards, sound cards, etc. Make sure 
the scanner's IRQ number or DMA channel or I/O address is not the same as the
other devices on the system.  Any conflicts with IRQ, DMA or I/O address 
settings should be avoided.  

For example, if there is a modem on COM2 (using IRQ 3), it will conflict 
with a scanner set to use IRQ 3.  The solution is to try a different 
available IRQ for the scanner.  Or if there is a sound card using DMA 1, it 
will conflict with a scanner set to use DMA 1.

After making sure there are no hardware conflicts, the next step is to
make sure the driver for the scanner (HHSCAND.SYS) is loading properly from 
the CONFIG.SYS file.  If not, verify the scanner line exists in the 
CONFIG.SYS and make sure it uses the proper syntax.   Next, make sure the 
driver is located in the directory which is mentioned in the scanner 

driver line in the CONFIG.SYS.

Software conflicts can cause the same symptoms as hardware conflicts, and
therefore must be avoided.  In order to determine the possible source of 
conflict, boot up the system with no AUTOEXEC.BAT file and a CONFIG.SYS 
file which only has the scanner driver, HHSCAND.SYS.  If this solves the 
problem, there is something being loaded in the CONFIG.SYS or AUTOEXEC.BAT 
file which conflicts with the scanner driver.  To determine the actual 
software which is causing the conflict, add back the contents of the 
CONFIG.SYS and AUTOEXEC.BAT files one line at a time until the scanner
fails again.

If the problem still persists and there are no apparent hardware or software
conflicts, try the scanner interface board in another expansion slot.  Make
sure the scanner connector is plugged all the way into the scanner port
on the back of the scanner interface board .  Also, check the scanner head
settings, such as contrast and resolution, to make sure they are set properly.
If the symptoms continue, try the scanner on another system to verify the 
scanner is working properly.