Owner's manual

17
MN138-1 Rev H
02/14
The Printed Circuit Boards (PCBs) contain components that are sensitive to
electrostatic discharge (ESD) and can damage the board if not handled properly.
As when handling any ESD-sensitive PCB, observe standard ESD safety
procedures.
4.7.1 Circuit Board Replacement
Circuit Board Removal
To remove the circuit board, follow the steps below:
1. Set the unit’s I/0 switch to the “0” position and unplug the power cord.
2. Remove both front and back panels.
3. In viewing unit from the back, remove fittings from top of both sieve beds. (This
step will allow easier access to circuit board when the compressor enclosure is
moved). Temporarily seal sieve bed openings with tape to prevent the sieve
material from being exposed to the moisture in room air.
4. In viewing unit from the front, locate circuit board and cut tie-wrap securing
tubing to the transducer on circuit board. Carefully remove tubing from circuit
board sensor.
Care must be taken when removing and installing tubing to circuit
board sensor to prevent damaging sensor.
5. Gently slide entire compressor enclosure towards you to allow access to wire
connections located at the back of the circuit board. (Do not pull out enclosure
too far as damage may occur to certain components within concentrator).
6. Locate and remove the 2-pin wire harness labeled ‘Compressor’ on circuit board.
7. In a clockwise manner, remove remaining wire harnesses from circuit board.
These are wire harnesses labeled: AC Power, Buzzer, PowerSw, Temp Switch,
Fan, and the 6-pin wire harness located at the back of the circuit board labeled
‘Valves’.
If unit is equipped with an O2 monitor system, there will be two
additional wire harness connections labeled O2 LED and Sensor
that should be disconnected from the circuit board before removal.
8. Using a Phillips-head screwdriver, remove screws securing circuit board in place.
Circuit Board Installation
To install the circuit board, follow the steps below:
1. Located at the back of the circuit board, reconnect wire harness to connection
labeled Valves on circuit board.
2. Care should be taken when reconnecting any wire harness to assure they are
installed properly.
3. Perform the remaining steps listed in the circuit board removal procedure in
reverse order.
4. Replace compressor enclosure to its original position and reconnect fittings to the
top of each sieve bed, being careful not to over tighten.
5. Install tubing to the top barb of transducer located on the circuit board. Secure
with tie-wrap.