Service manual

LUMISCAN ACR-2000 SERVICE MANUAL – SECTION 7.0 DIAGNOSTICS
This is an inverted signal with the highest amplitude at the bottom of the plot, which is a value of
zero. If the amplitude is not near zero, as an example 500 or 1000, the Laser is not emitting enough
light and needs to be replaced.
The screen detector plot for older ACR Readers is three spikes, each with an amplitude of
approximately 1600. ACR Readers with Data Acquisition PCA part numbers 0070-735 and below
have this older screen detector. If the spike amplitude is significantly below 1600, as an example 500
or 1000, the Laser is not emitting enough light and needs to be replaced.
If there are less than three spikes visible, the Laser may not be aligned with the screen detectors. The
procedure to realign the old style screen detectors is in the Chapter 5 paragraph titled, Plate
Detector Alignment.
7.2.4 Non Uniformity of Density
Non uniformity of density is where one side of the image is significantly darker or lighter than the
other side. The primary cause for this is a failed PMT. To determine which one of the two PMTs has
failed, attempt scans with each PMT disconnected from its cable. The PMT that, while disconnected,
has no effect on scanned images is the PMT that needs to be replaced. When replacing a PMT, be
sure to perform the PMT Output Voltage Balancing Procedure and the Calibration Table
Generation Procedure. Both of these procedures are in Chapter 5.