e. Safety Light. When the SAFETY light comes on when you are making an
exposure, the following conditions could exist.
(1)
(2)
The cooling-chimney filament-driver transistor is shorted.
(3)
There is a fault on the filament-control PCB.
(4)
The ma overload shunt is open or miscalibrated.
(5)
The X-ray tube is gassy and/or arcing.
(6)
The X-ray cable is arcing.
(7)
(8)
f. Terminated Exposures. If the autotimer terminates an exposure
immediately, the following conditions may be present.
(1) A fault in the ion-chamber pickup. (See AEC troubleshooting,
paragraph 2-21.)
(2)
A fault in autotimer PCBs. (See AEC troubleshooting.)
(3)
Look for an open in the density selector(s). (See AEC troubleshooting.)
g. Unterminated Exposures. If the autotimer does not terminate exposures,
the following conditions could be present.
(1)
The back-up time is set too short.
(2)
The wrong field was selected (operator error).
(3)
The table is in an incorrect patient position (operator error).
(4) There is a loose or misconnected ion-chamber pickup. (See AEC
troubleshooting.)
(5)
There is a fault in an ion-chamber pickup. (See AEC troubleshooting.)
(6)
There may be a fault in the autotimer PCBs. (See AEC troubleshooting.)
MD0351
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