Hill-Rom VersaCare P3200, Service Manual

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2.65 Junction Board Debugging—IntelliDrive® Transport System
Chapter 2: Troubleshooting Procedures
connector pins at P6 on the Junction board. Also, check connectors P2 and P5
where the enable switches plug into the Junction board.
The combined enable switch signal connects to the PACM board via the
Junction-PACM board cable. To verify the signal is being received at the
PACM board, unplug the 14-pin cable from the PACM board and measure
continuity across pins 1 and 3. When either switch is depressed the switch
closure can be measured across the pins.
Throttle Debugging
The base part of the handle that connects to the frame contains a strain element
that provides an output signal proportional to the force applied to the handle.
The handles are very similar to the load beams used in the scale system. The
Junction board amplifies this signal and provides an output to the PACM
board.
Verify the output signal is correct at P6.10. P6. 4 is used as a ground reference
for measuring signals. When no force is applied to the handle the output signal
should measure 2.4V to 2.6V DC. The voltage output can be adjusted by
turning potentiometer R1 until the output signal measures 2.5V. When either
handle is pushed, the output signal will increase until it reaches 4.0V to 4.5V.
When either handle is pulled the output signal will decrease until it reaches
0.4V to 1.5V. This indicates the throttle circuit working correctly.
Before making any adjustments verify the supply voltages. The supply voltage
at P6.8 will measure more than 22 V on a working system. If no voltage is
present, or the battery voltage is low, go to the battery checkout procedure.
The excitation voltage, P3.5 and P7.5 (red wire) will measure 10V to 12V on a
working board. Also, the signal voltages at P3.3, P7.3, P3.4, and P7.4 will be
approximately ½ the voltage measured at P3.5 and P7.5. These are the green
and white wires on the handle connectors P3 and P7. If the excitation voltage is
lower than 10V, unplug the connectors P3 and P7 one at a time to see if the
voltage comes into range. If this occurs, one of the handles is probably
damaged and needs to be replaced. If the voltage never comes into range,
verify the 12V supply at U2.2 to P6.4 on the Junction board. If a bad strain
element is suspected, unplug the bad handle, readjust the zero output to 2.5V
with potentiometer R1. Verify the bed power unit operates using the good
handle. Replace the damaged handle.
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VersaCare™ Bed Service Manual (MAN333 REV 2) Page 2 - 79