Troubleshooting Guide: 255 LED Light Note Use only factory replacement lights (refer to parts list for order number). Caution Carefully handle parts near membranes and wire harnesses. Allow the light to cool before removing. Carefully move the light away from the exam site to prevent contaminants from falling into the area. Warning Always disconnect power before removing covers. Failure to do so may result in personal injury. Contents Description Refer To: Troubleshooting - Troubleshooting Charts LED Lighthead Replacing the LED Light Module LED Lighthead Removal / Installation Fuse(s) Replacing the Fuse (Ceiling) Replacing the Fuses (Wall) Replacing the Fuse (Mobile) Adjustments / Repair Procedures LED Driver Board LED Driver Board Removal / Installation Power Supply Power Supply Removal / Installation Cross Tube Cross Tube Counterbalance Adjustment Cross Tube Removal / Installation Down Tube (Ceiling) Down Tube Removal / Installation Pivot Stops Pivot Stop Index Voltage Measurements - Overview Light Module Driver Board Keypad / Button Power Supply Vertical / Down Tube English-1 004-1042-00 [Revised: 7/7/16]
Quick Reference for 255 LED Light Illumination (also refer to 255 Troubleshooting Chart section): If below information does not resolve the issue, then contact technical service at 1-800-MIDMARK (643-6275). Connect power to LED light then confirm power cord connection. Do the indicator lights flash ON and OFF? Note Take all measurements on the driver board. Light intensity will gradually dim during driver board issues and be instantly dim during lighthead issues. No Check the circuit breaker/ power source. No Check fuses. No Check wiring in vertical / down tube. Is the reading 24 VDC? No Check power supply. Reading 24 VDC (Pin 2 (-)/Pin 3 (+) on 4-Pin connector on power supply PCB)? No Replace power supply. Yes Yes Yes Press the power button. Does the LED light illuminate? No Confirm approx. 12 VDC voltage at LED light module. No Replace driver board. Check lighthead switch membrane connections. Reading 5 VDC (Pin 10 (-)/ Pin 1 (+) on membrane harness? No Replace wiring in vertical / down tube Yes Yes Replace LED light module. Check driver board. Reading 24 VDC (Pin 3 (-)/ Pin 4 (+) on J1)? No Repair wiring in cross tube/lighthead. Is the intensity dim/lower/less than expected? Yes Check lighthead. SEE NEXT PAGE Test Points Red Lead (+) Black Lead (-) Pin 3 Pin 2 Pin 4 Pin 1 Pin 5 Pin 8 Yes Confirm 12 VDC at LED light module. Yes No Replace driver board. Pin 6 Pin 7 Replace LED light module English-2 004-1042-00 [Revised: 7/7/16]
Quick Reference for 255 LED Lighthead (also refer to 255 Troubleshooting Chart section): If below information does not resolve the issue, then contact technical service at 1-800-MIDMARK (643-6275). Note Light intensity will gradually dim during driver board issues and be instantly dim during lighthead issues. Check lighthead. Is faceplate in bad condition? No Check intensity controls. Set incorrectly? No Check LED Light module. Reading 12 VDC? No Replace LED light module. Yes Yes Replace faceplate. At highest intensity, reading is 11 VDC? Yes Replace driver board. English-3 004-1042-00 [Revised: mo/dd/yr]
Troubleshooting Chart Problem Symptom Probable Cause Check Solution Light will not illuminate. Arm assemblies can be rotated farther than specified (and/ or make noise, do not move freely, drift when released) Arm assemblies or lighthead does not rotate freely, or drifts when released. Mobile Lights only: Brake caster(s) will not lock. Light does not function when light is ON. Light does not function, or functions intermittently when lighthead or arm assemblies are moved. Cross tube (at ball pivot) can be rotated more than 580 in one direction. Mobile light cross tube can be rotated more than 540 in one direction. Lighthead can be rotated more than 180 in one direction. Ceiling Mtd Lights only: Down tube can be rotated more than 580 in one direction. Wall Mtd Lights only: Fixed arm can be rotated more than 170 (collides with wall). Cross tube rotates (at ball pivot joint) too tightly, or drifts when released. Lighthead does not rotate freely (at cross tube), or drifts when released. Ceiling Mtd Lights only: Down tube does not rotate, or drifts when released. If ceiling plate is not level, readjust as necessary. If there is excessive flexing, support ceiling structure as necessary (Refer to installation guide). Base moves when casters are set. Facility circuit breaker is tripped. Check facility circuit breaker. Reset circuit breaker. Line fuse(s) blown. Inspect fuses. Replace fuse(s). Ceiling Mounted Lights Wall Mtd. Lights Mobile Lights Fuse holder malfunctioning. Perform continuity check on fuse holder. Replace fuse holder. Switch membrane malfunctioning. Perform continuity check on switch. Replace switch membrane. Power supply malfunctioning. Check connections and voltage. If proper voltage is not present, replace power supply. Driver board malfunctioning. Check connections and voltage. If proper voltage is not present, replace driver board. LED light module malfunctioning. Check connections and voltage. If proper voltage is not present, replace LED light module. Damaged / disconnected wiring in the arm assemblies. Damaged / disconnected wiring in the arm assemblies. Perform continuity check on wiring from transformer to lighthead. Perform continuity check on wiring from transformer to lighthead. Repair / replace any damaged or disconnected wiring. (Refer to Wiring Diagrams) Repair / replace any damaged or disconnected wiring. (Refer to Wiring Diagrams) Ball pivot stop is broken. Inspect ball pivot stop. Replace ball pivot stop. Ball pivot stop is broken. Inspect ball pivot stop stop. Replace ball pivot stop. Lighthead pivot stop is broken. Inspect lighthead pivot. Replace lighthead pivot stop. Main pivot stop is broken. Inspect main pivot stop. Replace main pivot stop. Stop screw is missing / broken. Inspect fixed arm stop screw. Replace stop screw. Cross tube counterbalance out of adjustment. Lighthead tension out of adjustment. Improper installation of ceiling plate. (Plate deflecting too much, or not level) Improper installation of wall mount plate, or fixed arm not level. Base casters are worn or malfunctioning. Release tension from ball pivot joint and observe to see if the cross tube counterbalances correctly. Lighthead tension out of adjustment. Improper installation of ceiling plate. (Plate deflecting too much, or not level) Improper installation of wall mount plate, or fixed arm not level. Inspect base casters. Release tension from ball pivot joint and observe to see if the cross tube counterbalances correctly. Lighthead adjustment If ceiling plate is not level, readjust as necessary. If there is excessive flexing, support ceiling structure as necessary. (Refer to installation guide) Adjust fixed arm leveling screws as necessary (Refer to installation guide). Replace base caster(s) as necessary. English-4 004-1042-00 [Revised: mo/dd/yr]
Replacing the LED Light Module Caution Carefully handle parts near membranes and wire harnesses. Allow the light to cool before removing. Do not touch any non-black colored part of the LED light module. Carefully move the light away from the exam site to prevent contaminants from falling into the area. Warning Always disconnect power cord and allow time for light to cool before replacing. Do not touch the cone section of the LED light or reflector in light housing. LED Light Module To install light... A) Turn light OFF ( O I ). B) Turn OFF facility power breaker so there is no power in customer supplied wiring. C) Remove screws and screw caps from reflector. D) Separate front ring and faceplate from reflector. E) Disconnect LED light module connector from LED light module. F) Remove screws from LED light module. G) Peel film paper off new LED light module then install into previous place holding LED light module with a clean cloth. H) Complete steps B through F in reverse order. I) Connect power and verify operation. Reflector LED Light Module Screw * NOTE: Use only factory replacement lights (refer to parts list for order number). Sterilizable Handle Front Ring Faceplate Screw/Cap English-5 004-1042-00 [Revised: mo/dd/yr]
Lighthead Removal / Installation WARNING Disconnect power to the light before performing the following procedure. Failure to comply may result in electric shock. Step 1: Remove lighthead. A) Disconnect power to light. B) Remove screws and yoke assembly cover set. C) Remove two shoulder screws. D) Remove two pivot stops and washers. E) Separate yoke from lighthead and disconnect two wires. Shoulder Screw Note the order of all the washers and reassemble in their original positions. Correctly position pivot stops as shown into matching groove in yoke. Yoke Cover Matching Groove In Yoke Lighthead Washers *short width side Pivot Stop *long width side Screw Cover Pivot Stops Washers Shoulder Screw WARNING Mounting hardware on the lighthead must installed properly. Failure to do so may allow lighthead to fall, resulting in injury. Step 2: Install lighthead. A) Lubricate washers and shoulder screws. B) Place yoke. C) Install pivot stops, washers and shoulder screws to yoke as shown. D) Install lighthead and secure with two shoulder screws. Torque shoulder screws to 75 in-lb. E) Connect two wires. F) Install cover set. G) Install screws to cover set. H) Connect power and check for proper operation. Lighthead English-6 004-1042-00 [Revised: mo/dd/yr]
Replacing the Fuses: Ceiling Mounted Lights To replace fuses... A) Turn light OFF ( O I ). B) Turn OFF facility power breaker so there is no power in customer supplied wiring. C) Remove screws, then lower ceiling cover. D) Using a flat-bladed screwdriver, rotate fuse cap counter-clockwise 1/4 turn, while pushing upward. E) Remove fuse from fuse cap and inspect. F) Insert fuse into fuse cap. G) Using a flat-bladed screwdriver, rotate fuse cap clockwise 1/4 turn, while pushing into fuse socket. H) Install ceiling cover. I) Connect power and verify operation. Note: Inspect the fuse to determine whether it is faulty. There are two fuses on the double light and one fuse on the single light. Replacing the Fuses: Wall Mounted Lights To replace fuses... A) Turn light OFF ( O I ). B) Turn OFF facility power breaker so there is no power in customer supplied wiring. C) Remove screws, then bracket cover. D) Using a flat-bladed screwdriver, rotate fuse cap counter-clockwise 1/4 turn, while pushing upward. E) Remove fuse from fuse cap and inspect. F) Insert fuse into fuse cap. G) Using a flat-bladed screwdriver, rotate fuse cap clockwise 1/4 turn, while pushing into fuse socket. H) Install bracket cover. I) Connect power and verify operation. Note: Inspect the fuse to determine whether it is faulty. Bracket Cover Fuse Fuse Cap Fuse CRAFTSMAN Ceiling Cover CRAFTSMAN Fuse Cap MA8474i English-7 004-1042-00 [Revised: mo/dd/yr]
Replacing the Fuses: Mobile Lights Driver Board Removal / Installation: To replace fuses... A) Turn light OFF ( O I ). B) Disconnect power from light. C) Using a flat-bladed screwdriver, push in on locking tab, then pull fuse drawer out. D) Pull fuses out of fuse drawer to inspect. E) Insert fuses into fuse drawer. F) Insert fuse drawer into AC inlet (push in until you hear a clicking sound). G) Connect power and verify operation. Note: Inspect the fuse to determine whether it is faulty. Harnesses Do not damage harnesses when removing cover. Step 1: Access driver board. A) Turn light OFF and disconnect power. B) Remove cover and components from back of lighthead assembly shown. Driver Board Location Cover Fuses MA8475i Fuse Holder Lighthead Assembly English-8 004-1042-00 [Revised: mo/dd/yr]
Driver Board Removal / Installation (continued): Step 2: Remove driver board. A) Disconnect wire harnesses. B) Remove screws from cover shown. C) Carefully remove driver board off cover using a flat head screwdriver. Screw Locations Harnesses Screw Locations Step 3: Install new driver board. A) Peel off film from driver board back and align driver board before placing. B) Complete Steps 1 through 2 in reverse order. C) Connect power and verify operation. English-9 004-1042-00 [Revised: mo/dd/yr]
Power Supply Removal / Installation: Step 1: Removing existing power supply. A) Disconnect wire harnesses. B) Use needle nose pliers to release power supply. Power Supply Power Supply Base Power Supply Bottom Plate Weldment Wall Mounted Light Ceiling Mounted Light Mobile Light Wire Harnesses Power Supply Power Supply Step 2: Install new power supply. A) Secure power supply. B) Install components (reverse Step 1) as needed. C) Connect power and verify operation. English-10 004-1042-00 [Revised: 2/1/16]
Cross Tube Removal / Installation (Ceiling) Ball Pivot Sleeve WARNING Disconnect power to the light before performing the following procedure. Failure to comply may result in electric shock. The cross tube / lighthead is very heavy. To prevent injury, use an assistant for the following procedure. To remove cross tube... A) Disconnect power to light. B) Remove screw, then slide pivot sleeve up. C) While supporting cross tube / lighthead, remove two screws, then separate cross tube from down tube. D) Disconnect wire harnesses and remove cross tube. Phillips Head Screw Down Tube Cross Tube Assembly Wire Harnesses Button Head Screws WARNING Screws securing cross tube must be installed properly. Failure to do so may allow lighthead to fall, resulting in injury. To install cross tube... A) Slide ball pivot sleeve onto down tube making sure screw hole in sleeve is towards the bottom. B) With ball pivot sleeve positioned as high as possible on down tube, pull wire harness through top window of down tube. C) Align three screw holes; then insert pivot shaft of cross tube assembly into down tube. Secure cross tube assembly in position with two #10-24 x 3/8 button head screws. D) Feed wire harness through top window of down tube. E) Connect wire harnesses. Push harness into top window. F) Slide ball pivot sleeve down into position and secure with one #10-24 x 3/8 (New Units Only) phillips head screw. G) Refer to Ball Pivot Tension Adjustment if necessary. H) Slide pivot sleeve down, secure with screw. Note Male connector is power. Connectors are small size so use small probes to measure voltage. English-11 004-1042-00 [Revised: mo/dd/yr]
Cross Tube Removal / Installation (Mobile) Align three screw holes on the vertical tube with holes in ball pivot housing of the counterbalance assembly before installing any screws. Failure to comply may result in damage to screws. Install counterbalance assembly. A) Align three screw holes, then insert cross tube into vertical tube. B) Install two screws into the holes at the top of the vertical tube. C) Pull two wires from cross tube through bottom access hole. D) Connect wires from cross tube to corresponding wires from vertical tube, then push wires into tube. E) Slide sleeve into position, then secure with screw. Sleeve English-12 004-1042-00 [Revised: mo/dd/yr]
Ball Pivot Tension Adjustment / Cross Tube Counterbalance Adjustment To adjust ball pivot tension... A) Remove screw, then slide sleeve down. B) Insert screwdriver into adjustment hole. C) Move the screwdriver LEFT / RIGHT to adjust tension setting (LEFT: decreases tension / RIGHT: increases tension) D) Remove screwdriver, and check for desired tension. Repeat until desired tension is achieved. E) Slide ball pivot sleeve up, then install screw. To adjust cross tube counterbalance... A) Release tension. B) Remove cap from counterbalance. C) Loosen / tighten the adjustment screw until the cross tube balances in horizontal position. D) Install cap onto counterbalance. E) Set tension. Note: Turning the adjustment screw clockwise will lower the lighthead. Turning the adjustment screw counterclockwise will raise the lighthead. Adjustment Hole Housing Cap CRAFTSMAN Adjustment Screw Sleeve MA8517i English-13 004-1042-00 [Revised: mo/dd/yr]
Down Tube Removal / Installation (Ceiling Light) Step 1: Remove cross tube / lighthead. Refer to: Cross Tube Removal / Installation. Step 2: Remove down tube. A) Remove four screws and ceiling cover. B) Remove two screws, then separate down tube. C) Route wire harness up through down tube. WARNING Screws securing down tube must be installed properly. Failure to do so may allow lighthead to fall, resulting in injury. Step 3: To install down tube / ceiling cover... A) Install down tube, then secure with two screws. B) Position ceiling cover, then secure with four screws. Step 4: Install cross tube / lighthead. Refer to: Cross Tube Removal / Installation. English-14 004-1042-00 [Revised: mo/dd/yr]
Pivot Stop Index (Replacements / Repair / Adjustments) Stop Screw Leveling Screws Wall Tube Leveling Screws Ball Pivot Adjustment Down Tube (Ceiling) Ball Pivot Repair Yoke/Cross Tube Ball Pivot (Mobile) Ball Pivot Lighthead/Yoke English-15 004-1042-00 [Revised: mo/dd/yr]
Down Tube (Ceiling) Pivot Replacement Step 1: Remove cross tube / lighthead. Refer to: Cross Tube Removal / Installation. Step 2: Remove down tube. Refer to: Down Tube Removal / Installation. Place groove pin next to the wire harness, so wiring does not get pinched when pin is installed. Step 3: Replace main pivot stop. A) Remove groove pin. B) Remove washer, pivot housing, and pivot stop. C) Inspect two stop pins. Replace pin(s) if damaged. D) Install main pivot stop, pivot housing, and washer onto shaft. E) Install groove pin. Shaft Main Pivot Stop A Stop Pins Step 4: Install down tube. Refer to: Down Tube Removal / Installation. Step 5: Install cross tube / lighthead. Refer to: Cross Tube Removal / Installation. Washer A Groove Pin English-16 004-1042-00 [Revised: mo/dd/yr]
Ball Pivot Repair Step 1: Remove cross tube / lighthead. Refer to: Cross Tube Removal / Installation. Note the order of all the washers and reassemble in their original positions. Ball pivot must be supported when removing/installing groove pin to avoid damage to four screws. Step 2: Remove ball pivot assembly. A) Place screwdriver into adjustment hole. B) Move the screwdriver LEFT until tension is fully released. C) Carefully pull harness wires up. D) Remove groove pin using a punch tool. Adjustment Hole Washers Thrust Washer Washer (Large) Pivot Bearing (teflon side UP) Bearing Retaining Ring Washer (Large) Cam CRAFTSMAN Wave Washer Washers Step 3: Disassemble the ball pivot. A) Remove retaining ring and washers from ball pivot shaft. B) Using a punch, remove groove pin. C) Disassemble ball pivot components from shaft / housing. D) Inspect pivot bearing for excessive wear. Replace if necessary. Note: Groove pin has serrations on one end. Do not drive serrations through ball pivot shaft. Step 4: Assemble the ball pivot. A) Install pivot bearing, washers, and cam as shown. B) Install groove pin. C) Install washer, then secure with retaining ring. Groove Pin Ball Pivot Step 5: Install cross tube / lighthead. Refer to: Cross Tube Removal / Installation. Ball Pivot Brake Shaft Note Ceiling/wall shown. Wave Washer English-17 004-1042-00 [Revised: mo/dd/yr]
Ball Pivot Stop Replacement Pivot Stop Step 1: Remove the ball pivot. Refer to: Ball Pivot Repair. Stop Pin (replace if damaged) Step 2: Replace ball pivot stop. A) Remove two flange bearings from shaft. B) Disassemble shaft / housing components. C) Inspect groove pin. Replace if necessary. D) Install pivot stop (with raised portion facing UP), housing, and brake to shaft. E) Install two flange bearings to shaft. Note: Groove pin has serrations on one end. Do not drive serrations through shaft. Step 3: Assemble the ball pivot. Refer to: Ball Pivot Repair. Shaft Groove Pin Flange Bearings English-18 004-1042-00 [Revised: mo/dd/yr]
Lighthead Pivot Stop Replacement Note the order of all the washers and reassemble in their original positions. Step 1: Remove pivot stop. A) Remove screws from cover set. B) Remove cover set. C) Remove pivot stop and washers from shoulder screw. D) Remove shoulder screw from yoke. Correctly position pivot stops as shown into matching groove in yoke. Yoke Cover Set Matching Groove In Yoke Shoulder Screw Washers *short width side Pivot Stop *long width side Cover Set A Pivot Stops Washers Screws WARNING Mounting hardware must be installed properly. Failure to do so may allow lighthead to fall, resulting in injury. A Step 2: Install pivot stop. A) Install previously removed washers and shoulder screw to yoke. B) Install pivot stop to shoulder screw. Torque shoulder screw to 75 in-lb. C) Install covers. D) Install screws to cover set. Shoulder Screw Lighthead English-19 004-1042-00 [Revised: mo/dd/yr]
Yoke Pivot Replacement Step 1: Disassemble yoke. A) Remove screws from cover set. B) Remove cover set. C) Remove nut from the top of the assembly. D) Remove screw and insert from pivot bearing. E) Remove washers, shaft and pivot from yoke. F) Inspect pivot for excessive wear. Replace if necessary. G) Inspect mount on yoke. Replace if necessary. See Lighthead Pivot Stop Replacement to remove / install yoke. Note the order of all the washers and reassemble in their original positions. Washers Nut Pivot Insert WARNING Mounting hardware must be installed properly. Failure to do so may allow lighthead to fall, resulting in injury. Yoke Screw Step 2: Resassemble yoke. A) Install yoke and/or pivot (if needed). B) Lubricate washers then install washers, shaft and pivot to yoke. Ensure shaft end matches correctly in yoke hole. C) Install screw and insert to pivot. D) Install nut to the top of the pivot assembly. Torque nut to 75 in-lb. E) Install cover set. F) Install screws to cover set. Washers Mount Yoke Weldment Hole Shaft Cover Set Screws Shaft End English-20 004-1042-00 [Revised: mo/dd/yr]
Voltage Measurements Overview Driver Board Power Connector Measuring Side (For Multi-meter) 6 Warning Always disconnect power before removing covers. Failure to do so may result in personal injury. Refer to Adjustments / Repair Procedures. Ensure the PC Board does not touch the metal weldment under it. 10 Light Module Connector 3 1 1 4 MA10054 Keypad/Button Connector Power Supply With Connector Removed 16 MA10053 English-21 004-1042-00 [Revised: 7/7/16]
Voltage Measurements - Light Module WARNING Insert multimeter probes carefully. To measure... A) Set light at brightest setting available B) Using multimeter, check LED lights by row on capacitors as shown. C) Measure voltage. Reading should be 12 VDC in each of the four rows. Pin to Capacitor + / - 3 C59-4 C58-5 C64 + 6 C63 + 7 C62 + 8 C61 + 9 C57-10 C56 - Ensure the PC Board does not touch the metal weldment under it. Measuring Side (For Multi-meter) Light Module Connector 10 LED Row 1 LED Row 2 LED Row 3 3 LED Row 4 English-22 004-1042-00 [Revised: 7/7/16]
Voltage Measurements - Driver Board WARNING Insert multimeter probes carefully. To measure... A) Set light at brightest setting available. B) Using multimeter, check pin 3 (-) and pin 4 (+) on connector as shown. C) Measure voltage. Reading should be 24 VDC. Ensure the PC Board does not touch the metal weldment under it. 1 Pin 3 (-) Pin 4 (+) 6 MA10056 English-23 004-1042-00 [Revised: 7/7/16]
Voltage Measurements - Keypad / Button WARNING Insert multimeter probes carefully. To measure... A) Set light at brightest setting available. B) Using multimeter, check pin 12 (-) and pin 16 (+) on connector as shown. C) Measure voltage. Reading should be 5 VDC. Ensure the PC Board does not touch the metal weldment under it. Do not let the pins touch each other. 1 Pin 12 (-) Pin 16 (+) MA10057 English-24 004-1042-00 [Revised: 7/7/16]
Voltage Measurements - Power Supply WARNING Do not touch pins or other components outside PCB protective barrier. Insert multimeter probes carefully. To measure... A) Remove connector as shown. B) Measure voltage on Pin 2 (-) and Pin 3 (+) Reading should be 24 VDC. Ensure the PC Board does not touch the metal weldment under it. Connector Pin 2 (-) Pin 3 (+) 1 4 MA10059 English-25 004-1042-00 [Revised: 7/7/16]
Voltage Measurement - Vertical / Down Tube WARNING Disconnect power to the light before performing the following procedure. Failure to comply may result in electric shock. Insert multimeter probes carefully. To measure harnes... A) Turn light OFF ( O I ) then disconnect power to light. B) Remove screw, then slide pivot sleeve up. C) Feed wire harness connectors through tube window. D) Disconnect wire harnesses. E) Connect power and turn light ON. F) Measure voltage with small sized multimeter. Reading should be 24 VDC. G) Position pivot sleeve then secure with screw. Note Male connector is power. Connectors are small size so use small probes to measure voltage. Ball Pivot Sleeve Screw Wire Harnesses Tube English-26 004-1042-00 [Revised: 7/7/16]