Fault-Finding - Pyramid D100 User Manual

PSI System Controls and Diagnostics

14 Fault-finding

Symptom
No communication with host
system
No function
Poor energy resolution
Unstable energy calibration
D100 User Manual
Possible Cause
Transmit and receive fiber-
optic lines crossed.
Fiber-optic loop is broken
No 24 V power – faulty PSU
No 24 V power – bad jack
connector
Shaping time too small
Pile Up time too short.
Photomultiplier gain too low
Cable from photomuliplier to
D100 too long.
Unstable high voltage
D100_UM_081027
Confirmation
Check connections.
Trace connections around the
loop.
Check power status LED,
check PSU voltage
Check power status LED.
Power should be present and
not affected if connector or
cable is moved.
Resolution improves if value
is increased.
Resolution improves if value
is increased.
Resolution improves if gain is
increased.
Resolution improves with
shorter cable.
Check HV stability with
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Solution
Correct connections.
Correct connections.
Replace PSU
Replace connector
Increase the Shaping time.
Increase the Pile up time.
Increase gain.
Reduce the cable length if
possible, otherwise increase
the Shaping time.
Replace supply.