When a membrane touchpad or foot control switch is pressed, nothing happens and relays cannot be heard energizing.

Power cord is not plugged into facility wall outlet.

Check to see if power cord is plugged in.

Facility circuit breaker providing power to chair is tripped.

Check to see if facility circuit breaker is tripped. Plug a lamp into wall outlet that chair was plugged into and see if it operates.

Wire connections are loose.

Check all wiring connections from power cord to PC circuit board. Use a multimeter to perform continuity checks on wires.
Check for line voltage at plug J19 (line power input) on pins 2 (blue) and 4 (brown).

Fuse blown.

Remove fuse, F1, F2, and F3 from PC board and check fuses for continuity.

PC circuit board is malfunctioning.

Note: Incoming Line voltage is present at Power Input, J19, pins 2 [Blue] and 4 [Brown].

Check for 12 VDC on pins 1 and 2 of J14.

Check the LED’s next to related relay when the specific function is being operated.

Check visually for damage components and broken traces on PC board.

Chair has power, but no functions can be initiated from membrane touchpad and foot control.

Plug connector(s) loose or wire harnesses broken.

Check all plug connectors and harnesses.

Some functions can be initiated with membrane touchpad or foot control, but at least one cannot.

Switch on Membrane Touchpad or Foot Control is malfunctioning.

Perform a continuity check on each N.O. control switch in control when switch is pressed, switch circuit should be closed. Refer to: J1 thru J5 Control Pendants Connectors and Switches

Wires Broken or connections loose .

Check all wiring and related connections between control switches and PC circuit board.

Capacitor for hydraulic pump motor weak or bad. Up functions would not work.

Replace capacitor with a known good capacitor and check operation.

PC Board malfunctioning.

Note: Incoming Line voltage is present at Power Input, J19, pins 2 [Blue] and 4 [Brown].

Check for 12 VDC on pins 1 and 2 of J14.

Check the LED’s next to related relay when the specific function is being operated.

Check visually for damage components and broken traces on PC board.

Back or Base potentiometer plug is loose from specific potentiometer or wire leads are broken.

Check conditions of plug connectors and wire leads to potentiometers.

Back or Base potentiometer is out of adjustment.

Check adjustment of Base and/or Back potentiometer(s).

When any Back Up button is depressed, chair will not move, all other functions work.

Back Up solenoid coil has an open winding, disconnected or broken lead.

Check all wires to Back Up Solenoid and connections at P.C. Board, pins 2 and 3 on J18. Check solenoid for an “open” coil. Refer to: Wiring and Tubing Diagrams.

Back Up solenoid valve stuck in closed position .

After checking solenoid coil , connections, and wires, assure coil is energized when depressing Back Up.

Throttle Valve (TV3) on Hydraulic Solenoid Valve Assembly turned in too far or completely closed.

Check position of TV3 Throttle Valve. Refer to: Back Up hydraulic function.

Hydraulic Back cylinder leaking.

Check for leakage around hydraulic cylinder and fittings. Check for excessive fluid returning to reservoir from Vent line.

Hydraulic Solenoid Valve Assembly is clogged preventing fluid flow.

Check for hydraulic fluid flow to Back Cylinder during operation. Refer to: Back Up Hydraulic Function.

Back potentiometer plug is loose from potentiometer or wire leads are broken.

Check conditions of plug connectors and wire leads to potentiometer.

Back potentiometer is out of adjustment.

Check adjustment of Back potentiometer.

Back Potentiometer is damaged.

Check potentiometer. Refer to: Testing Potentiometer.

When any Back Down button is depressed, chair will not move, all other functions work.

Safety Bail Limit Switch(es) harness not installed correctly (loose).

Check both harness to assure they are connected tightly.

Safety Bail Limit Switch(es) contacts open due to an obstruction hitting cover or Switch(es) malfunctioning, stuck open

Safety Bail cover depressing safety bail limit switch(es) actuator, opening contacts on switch.

Check continuity on unoperated switch to assure normally closed (NC) contacts are closed.

Back Down solenoid coil has an open winding, disconnected or broken lead.

Check all wires to Back Down Solenoid and connections at P.C. Board, pins 4 and 5 on J18. Check solenoid for an “open” coil. Refer to: Wiring Diagrams

Back Down solenoid valve stuck in closed position .

After checking solenoid coil , connections, and wires, assure coil is energizes when depressing Back Down.

Throttle Valve (TV4) on Hydraulic Solenoid Valve Assembly turned in too far or completely closed.

Check position of TV4 Throttle Valve. Refer to Hydraulic Solenoid Valve Assembly and Back Down hydraulic schematic. Refer to: Wiring Diagrams

Hydraulic Solenoid Valve Assembly is clogged preventing fluid flow.

Check for hydraulic fluid flow from Cylinder to Reservoir during operation. Refer to: Wiring Diagrams

Cuspidor Limit Switch contacts open due to cuspidor hitting obstruction or malfunction.

Check if cuspidor is hitting obstruction and/or if limit switch contacts are open.

Cuspidor not installed and Jumper wire on J10 plug connector missing.

Check for a jumper wire on P.C. Board plug connector J10.

Back potentiometer plug is loose from potentiometer or wire leads are broken.

Check conditions of plug connectors and wire leads to potentiometer.

Back potentiometer is out of adjustment.

Check adjustment of Back potentiometer.

Back Potentiometer is damaged.

Refer to: Testing Potentiometer.

When any Base Up button is depressed, chair will not move, all other functions work.

Base Up solenoid coil has an open winding, disconnected or broken lead.

Check all wires to Base Up Solenoid and connections at P.C. Board, pins 2 and 3 on J17. Check solenoid for an “open” coil. Refer to: Wiring Diagrams

Base Up solenoid valve stuck in closed position .

After checking solenoid coil , connections, and wires, assure coil is energized when depressing Base Up.

Throttle Valve (TV1) on Hydraulic Solenoid Valve Assembly turned in too far or completely closed.

Check position of TV1 Throttle Valve. Refer to: Base Up hydraulic function.

Hydraulic Base cylinder leaking.

Check for leakage around hydraulic cylinder and fittings. Check for excessive fluid returning to reservoir from Vent line.

Hydraulic Solenoid Valve Assembly is clogged preventing fluid flow.

Check for hydraulic fluid flow to Back Cylinder during operation. Refer to: Wiring Diagrams

When any Base Down button is depressed, chair will not move, all other functions work.

Safety Bail Limit Switch(es) harness not installed correctly (loose).

Check both harness to assure they are connected tightly.

Safety Bail Limit Switch(es) contacts open due to an obstruction hitting cover or Switch(es) malfunctioning, stuck open

Safety Bail cover depressing safety bail limit switch(es) actuator, opening contacts on switch.

Check continuity on unoperated switch to assure normally closed (NC) contacts are closed.

Base Down solenoid coil has an open winding, disconnected or broken lead.

Check all wires to Base Down Solenoid and connections at P.C. Board, pins 4 and 5 on J17. Check solenoid for an “open” coil. Refer to: Wiring Diagrams

Base Down solenoid valve stuck in closed position.

After checking solenoid coil , connections, and wires, assure coil is energizes when depressing Base Down.

Throttle Valve (TV2) on Hydraulic Solenoid Valve Assembly turned in too far or completely closed.

Check position of TV2 Throttle Valve. Refer to:Base Down hydraulic function. Refer to: Wiring Diagrams

Hydraulic Solenoid Valve Assembly is clogged preventing fluid flow.

Check for hydraulic fluid flow from Cylinder to Reservoir during operation. Refer to: Wiring Diagrams

Cuspidor Limit Switch contacts open due to cuspidor hitting obstruction or malfunction.

Check if cuspidor is hitting obstruction and/or if limit switch contacts are open.

Cuspidor not installed and Jumper wire on J10 plug connector missing.

Check for a jumper wire on P.C. Board plug connector J10.

Base potentiometer plug is loose from potentiometer or wire leads are broken.

Check conditions of plug connectors and wire leads to potentiometer.

Base potentiometer is out of adjustment.

Check adjustment of Base potentiometer.

Base Potentiometer is damaged.

Check potentiometer. Refer to: Testing Positioning Potentionmeter.

When Base Down and Back Down buttons are pressed, chair will not move. Base Up and Back Up functions work.

Safety Bail Limit Switch(es) harness not installed correctly (loose).

Check both harness to assure they are connected tightly.

Safety Bail Limit Switch(es) contacts open due to an obstruction hitting cover or Switch(es) malfunctioning, stuck open

Safety Bail cover depressing safety bail limit switch(es) actuator, opening contacts on switch.

Check continuity on unoperated switch to assure normally closed (NC) contacts are closed.

Cuspidor Limit Switch contacts open due to cuspidor hitting obstruction or malfunction.

Check if cuspidor is hitting obstruction and/or if limit switch contacts
are open.

When Base Up and Back Up buttons are depressed, chair will not move. Base Down and Back Down functions work.

Internal thermal overload on hydraulic motor pump open due to running continuously or weak or malfunctioning overload.

Check continuity between white and red motor leads and yellow and red leads. Refer to: Wiring Diagrams

Hydraulic Fluid in reservoir low.

Check reservoir for hydraulic fluid level.

Capacitor on motor pump weak or inoperative.

Replace capacitor with known good capacitor of same rating.

Low voltage is being supplied to chair.

Check voltage at wall receptacle - should be between 110.0 to 126.0 VAC on 115 VAC units or 220 to 252 VAC on 230 VAC units.

Hydraulic motor pump electrical leads disconnected.

Check electrical connections on PC Board at J16, terminals 2 and 3.

Hydraulic motor pump has open winding(s).

Check resistance values of motor windings. Refer to: Wiring Diagrams

Depressing specific function button, hydraulic motor pump continues to run when chair reaches top or bottom limitations.

Back or Base potentiometer plug is loose from specific potentiometer or wire leads are broken.

Check conditions of plug connectors and wire leads to potentiometers.

Back or Base potentiometer is out of adjustment.

Check adjustment of Base and/or Back potentiometer(s).

Chair moves slowly or not at all under heavier loads.

Capacitor for Hydraulic Motor Pump is weak.

Replace capacitor with known good capacitor of same rating.

Low voltage is being supplied to chair.

Check voltage at wall receptacle - should be between 110.0 to 126.0 VAC on 115 VAC units or 220 to 252 VAC on 230 VAC units.

Leakage past pressure relief valve.

Check for excessive fluid flowing back to reservoir.

Chair exceeds normal 15 second descent time from top position to bottom position w/ 180 lbs (82 kg) load on it.

Throttle Valve (TV4) is turned in too far restricting hydraulic fluid flow back to reservoir.

Check setting of Throttle Valve (TV4)

Noisy motor pump during Back Up or Base Up.

Restriction in Suction line from reservoir causing negative pressure.

Check for kinks in tubing and/or restrictions in suction line.

Excessive force is required to position the headrest.

Headrest slide is too tight and needs adjusted.

Check adjustment of headrest slide.

Brake is off, but chair top is binding when rotated.

Brake is out of adjustment, needs loosened.

Check adjustment of brake.

Brake lever is difficult to engage.

Brake is out of adjustment, needs loosened.

Check adjustment of brake.