Service manual

LUMISCAN ACR-2000 SERVICE MANUAL – SECTION 7.0 DIAGNOSTICS
7.2.7 No Galvanometer Movement
The most common cause of no Galvanometer movement is failed drive circuitry on the Data
Acquisition PCA.
Remove the AUX/IO connector from the Data Acquisition PCA to disable the PMT High Voltage
Power Supply. This will protect the PMTs from ambient light during the investigation.
Manually roll a 14X17 inch plate into to the beam slot to serve as a backdrop for the laser light.
Run DDT.EXE option 20 to activate the Galvanometer. Install the Laser interlock key.
If the beam is sweeping back and forth across the plate, the Galvanometer is functioning properly.
Disconnect the Galvanometer drive signal cable at the Data Acquisition PCA connector labeled
“GALVO”. Disconnect the other end of the same cable from the Galvo Driver PCA. Use an
oscilloscope to monitor the Galvo drive signal at the top pin of Test Point 6 on the DACQ PCA. If
there isn’t a drive signal present, the DACQ PCA is malfunctioning or is adjusted to zero Galvo
span.
If there is a drive signal present, connect the drive signal cable to the DACQ PCA while leaving the
other end disconnected. If the drive signal is lost, the cable needs to be replaced.
If the drive signal is still present, connect the drive signal cable to the Galvo Driver PCA. If the drive
signal is lost, the Galvo Driver PCA needs to be replaced.
If the drive signal is still present, verify with a DVM that the Galvo Driver PCA is receiving its input
voltage of +15VDC and –15VDC. This can be measured at L1 and L2 on the Galvo Driver PCA.
If the Galvo Driver PCA is receiving its proper input voltage, attach the oscilloscope to the junction
of R66 and R67 on the Galvo Driver PCA. If there is a drive signal, detach and reattach the
Galvanometer. If the Galvanometer still doesn’t function, it needs to be replaced. If there is no drive
signal to the Galvanometer, the Galvo Driver PCA needs to be replaced.