P/N 9-500-0255 5-3
Service Manual
Chapter 5: Maintenance—General
Troubleshooting
Output) ports. The Control Panel may be remotely located up to 50 feet from the
Gantry. The control panel contains the display screen, the display scroll and change
keys, reset switch, exposure initiate switch, compression release switch, and the
visual x-ray on indicator.
Two screens appear during the "power on" cycle to indicate the Control Panel and
Gantry configurations.
The "RUN" screen appears after the power on cycle. When all interlocks are satisfied
the message area displays "READY". At this point an exposure may be initiated.
There are several additional screens (User Default, Exposure Default, and four
Service screens) that are accessed by pressing the RESET and a Scroll arrow (->) key.
These screens permit the user to set power-on default settings and permit the service
engineer to access calibration settings.
The microprocessor in the Operator Control Panel is a Motorola HC-16 series with
support RAM, EPROM, and Video RAM chips. The display is a one-quarter VGA
LCD with backlight. The audible alert for x-ray indication is resident to the
Microprocessor board. A connector is supplied to permit the use of an external x-ray
switch. The board is supplied with +12 VDC and is regulated down to +5 VDC for
circuit operation.
3.1.2 Power Distribution
Power is derived from the incoming Mains Line voltage of 220/230 VAC nominal,
50/60 Hz, single-phase power. A line filter is utilized to reduce RFI/ENC emissions
and susceptibility to noise. The toroidal transformer isolates the incoming power
and multiple voltages are derived from the secondary windings. These voltages are
rectified and regulated, then distributed throughout the unit. There is a power on
surge circuit to limit the inrush current. The x-ray tube cooling fan is supplied with
its operating voltage and monitors the fan RPM feedback signal. This signal is
monitored by the Host microprocessor and inhibits the initiation of an exposure if
the fan is not running. There is a circuit that monitors the Emergency Off switches as
well as the coil connection to the circuit breaker. This circuit is monitored by the
Host microprocessor and inhibits any exposures or motions upon failure. Relay
contacts are available for external X-ray ON and Power ON lights. The Mains circuit
breaker serves as the unit ON/OFF switch.
3.1.3 System Control
System Control consists of the following printed circuit boards (PCB):
• Host Microprocessor
• Communication Interface
• C-arm Safety
• Power Control
Host Microprocessor
The Host microprocessor is a Motorola HC-16 series with support RAM and EPROM
chips. All system control is processed by this PCB. The RS-422 I/O port connects to
the Operator Control Panel to read the inputs and in turn supplies the appropriate
output signals to the Tube Control, High Voltage Control, and motors for system
operation. There are DIP switches located on this PCB for different system
configurations and operations.
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