Service manual

LUMISCAN ACR-2000 SERVICE MANUAL – SECTION 7.0 DIAGNOSTICS
7.2.3 System Will Not Detect Phosphor Screens
If the screen moves into the system several inches and stops without backing up, the screen is not
being detected. The most common cause of this failure is a failed Laser Module.
To determine if the Laser is functioning, remove the main enclosure, turn the Laser on and visually
determine if the Laser is functioning. Ensure that the interior of the scanner is not exposed to
ambient light, as this might damage the Photo-Multiplier Tubes. Also, enable the Laser interlock
with one of the interlock keys clamped to the side of the frame. To activate the Laser, run the
DDT.EXE program, which is located in the Lumisys “tools” directory. Then, select option 20,
which turns the Laser on and makes it scan back and forth across the light collection chamber. If the
Laser is not emitting light, the Laser Module needs to be replaced. If the Laser is emitting light, it is
possible that it is not emitting enough light.
To check for adequate Laser light, manually push an erased phosphor screen six inches into the
rollers. This will ensure that the screen is in the Laser path. Then run the DDT.EXE program from
the “tools” directory. Select option 20. Press the “i” key to activate the screen detector. Press the “p”
key to plot the detection signal. On most ACR Readers, the screen detector signal will appear as
follows.