355 Light Troubleshooting Chart

Symptom Probable Cause Check Solution
Light does not illuminate. ON / STANDBY switch is ON. Bulb is burned out. Inspect bulb. Replace bulb.
Facility circuit breaker is tripped. Check facility circuit breaker. Reset circuit breaker.
Line fuse(s) blown. Inspect fuses. Replace fuse(s).
Fuse holder malfunctioning. Perform continuity check on fuse holder. Replace fuse holder.
Bulb socket is corroded resulting in bad connection. Inspect / clean bulb socket. Replace bulb socket.
ON / STANDBY switch malfunctioning. Perform continuity check on switch. Replace ON / STANDBY switch.
Transformer malfunctioning. With the ON / STANDBY switch ON, check for 25-28 VAC across output leads of transformer. If 25-28 VAC is not present, Replace transformer.
Damaged / disconnected wiring in the arm assemblies. Perform continuity check on wiring from transformer to lighthead. Repair / replace any damaged or disconnected wiring. Refer to: Ceiling Mounted, Wall Mounted, or Mobile Wiring Diagram
Mobile Lights only: AC inlet is malfunctioning. Perform continuity check on AC inlet. Replace AC inlet.
Lighthead will not illuminate, or flashed intermittently when lighthead or arm assemblies are moved. Damaged / disconnected wiring in the arm assemblies. Perform continuity check on wiring from transformer to lighthead. Repair / replace any damaged or disconnected wiring. Refer to: Ceiling Mounted, Wall Mounted, or Mobile Wiring Diagram
Symptom Probable Cause Check Solution
Cross tube rotates at ball pivot joint too stiffly or drifts when released. Cross tube counterbalance out of adjustment. Release tension from ball pivot joint and observe to see if the cross tube counterbalances correctly.

Perform Cross tube counterbalance adjustment. Then, perform Ball joint tension adjustment.
Ball pivot joint tension out of adjustment. Check for looseness / stiffness in joint.
Lamp tube does not rotate freely at cross tube or drifts when released. Lamp tube brake tension out of adjustment. Check for looseness / stiffness in joint. Lamp tube brake adjustment.
Lighthead does not rotate freely at lamp tube or drifts when released. Lighthead brake tension out of adjustment. Check for looseness / stiffness in joint. Lighthead brake adjustment.
Ceiling Mtd Lights only: Down tube does not rotate, or drifts when released. Improper installation of ceiling plate. Plate deflecting too much, or not level. Inspect ceiling plate. Check for level and excessive flexing. If ceiling plate is not level, readjust as necessary. If there is excessive flexing, support ceiling structure as necessary. Refer to: 120V or 230V Ceiling Mounted Light Installation Guide
Wall Mtd Lights only: Fixed arm does not rotate freely, or drifts when released. Improper installation of wall mount plate or fixed arm not level. Inspect wall mount plate. Place a level on fixed arm. Adjust fixed arm leveling screws as necessary. Refer to: Wood Framed or Steel Framed Wall Mounted Light Installation Guide
Symptom Probable Cause Check Solution
Cross tube can be rotated more than 580° in one direction. Ball pivot stop is broken. Inspect ball pivot stop. Replace ball pivot stop.
Lamp tube can be rotated more than 540° in one direction. Lamp tube pivot stop is broken. Inspect lamp tube pivot stop. Replace lamp tube pivot stop.
Lighthead can be rotated more than 180° in one direction. Lighthead pivot bearing stop is broken. Inspect lighthead pivot bearing. Replace lighthead pivot bearing.
Ceiling Mtd Lights only: Down tube can be rotated more than 580° in one direction. Main pivot stop is broken. Inspect pivot stop. Replace main pivot stop.
Wall Mtd Lights only: Fixed arm can be rotated more than 170° (collides with wall). Stop screw missing / broken. Inspect fixed arm stop screw. Replace fixed arm stop screw.
Symptom Probable Cause Check Solution
Lighthead assembly illuminates but not at the proper intensity. Bulb malfunctioning. - Replace bulb.
Wrong input tap is being used on transformer or facility voltage has changed since installation. Check facility input voltage and transformer input tap being used. Select proper transformer input tap based on facility voltage.
Transformer malfunctioning. With the ON / STANDBY switch ON, check for 25-28 VAC across output leads of transformer. If 25-28 VAC is not present, Replace transformer.
Bulb socket corroded resulting in bad connection or high resistance. Inspect / clean bulb socket. Replace bulb socket.
IR filter is clouded or dirty. Inspect IR filter. Clean IR filter.
Faceplate is clouded or dirty. Inspect faceplate. Clean faceplate.
Components of lighthead damaged to the point that lighthead is no longer in tolerance. - Return lighthead to Midmark® for repair. Call 1.800.Midmark, follow the prompts for Technical Service.
Symptom Probable Cause Check Solution
Base moves when caster brakes are set. Caster brakes are worn or malfunctioning. Inspect caster brakes. Replace brake caster(s) as necessary.