OHAUS EB SERIES Service Manual Download Page 1

 

 

EB SERIES SCALES 
SERVICE MANUAL

 

 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Ohaus Corporation 7 Campus Drive, Suite 310, Parsippany, NJ 07054 (973) 377-9000 

Summary of Contents for EB SERIES

Page 1: ...EB SERIES SCALES SERVICE MANUAL Ohaus Corporation 7 Campus Drive Suite 310 Parsippany NJ 07054 973 377 9000...

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Page 3: ...e time of publication but Ohaus Corporation assumes no liability arising from the use or misuse of this material Reproduction of this material is strictly prohibited Material in this manual is subject...

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Page 5: ...ting the Main PC Board 2 9 2 8 1 Main PC Board Voltage Measurements 2 9 2 8 2 Simulator Testing 2 9 2 8 2 1 General Load Test 2 10 2 8 2 2 Calibration Test 2 10 2 9 Testing the Battery 2 11 2 9 1 Prec...

Page 6: ...1 3 2 Load Cell Overload Protection Stop Gap Settings 3 13 4 1 Repeatability Worksheet 4 2 4 2 Calibration Points 4 6 5 1 EB Series Scales Housing and Parts 5 3 A 1 Scale Resolution Settings A 2 LIST...

Page 7: ...Manual iii Ohaus Corporation www ohaus com FIGURE NO TITLE Page No 3 17 Overload Stop Locations 3 12 3 18 Battery Connections 3 14 4 1 Segment Display 4 1 4 2 Off Center Load Test Weight Locations 4 2...

Page 8: ...TABLE OF CONTENTS Ohaus Corporation www ohaus com iv EB Series Scales Service Manual...

Page 9: ...reliminary checks troubleshooting tables testing procedures and an interconnection diagram Chapter 3 Repair Procedures Contains detailed repair procedures for all major components Chapter 4 Final Test...

Page 10: ...E Adapters required for servicing are location dependent 1 3 CALIBRATION MASSES REQUIRED The masses required to test the EB Series Scales must meet the requirements of ASTM Class 4 or OIML Class F2 Th...

Page 11: ...nter of Zero Gross Tare Battery Status Hi OK Lo Units Keyboard 7 function membrane switch M Units Zero Tare Check Count Zero Range 4 of Full Scale Capacity Tare Range Full Capacity by Subtraction exce...

Page 12: ...NU STRUCTURE inC 01 EL AU AC 2d Fil 1 AU ON OFF 0 5d 1d 2d 4d 0 1 2 3 Levels d scale division mode dependent settings inC 01 EL AU AC 2d FiL 1 Scale increment Sets the displayed scale increment also k...

Page 13: ...s as received 2 3 TROUBLESHOOTING TABLES Troubleshooting tables 2 1 through 2 7 identify actual types of problems that could be encountered with the scale The troubleshooting tables refer to the EB Sc...

Page 14: ...e at the battery connector on the Main PC Board Voltage should read approximately 6 Volts DC minimum If voltage is not present at the connector disconnect the leads from the battery and make a continu...

Page 15: ...tion 3 3 1 After repair proceed with Performance Tests in Chapter 4 TABLE 2 4 NO DISPLAY OR PARTIAL DISPLAY SYMPTOM PROBABLE CAUSE REMEDY Display is not on or partial characters are displayed Display...

Page 16: ...ir proceed with Performance Tests in Chapter 4 Test the Main PC Board Section 2 8 If defective replace it Section 3 3 After repair proceed with Performance Tests in Chapter 4 TABLE 2 6 CANNOT CALIBRAT...

Page 17: ...efective Reposition the Pan correctly Ensure the Pan is empty before switching the scale on Test the Load Cell Section 2 7 If defective replace it Section 3 4 After repair proceed with Performance Tes...

Page 18: ...c minimum and 7 5 Volts dc maximum If the voltage is below or above these readings replace the Adapter This is the actual battery voltage while charging 2 6 TESTING THE MEMBRANE SWITCH The Membrane Sw...

Page 19: ...ust be isolated from chassis ground and shield Resistance should be greater than 5 megohms A lower reading indicates a short in either in the Load Cell cable or the Load Cell 4 Reconnect Load cell cab...

Page 20: ...NOMINAL OUTPUT IN MILLIVOLVTS AT 5 VOLTS EXCITATION CAPACITY NO LOAD 50 100 3 kg 6 kg 15 kg 30 kg 2 7 1 5 1 9 1 5 1 2 1 5 0 5 1 5 no load 3 2 no load 4 4 no load 5 2 no load 4 9 no load 6 4 no load 8...

Page 21: ...sure the excitation voltage across EXE and EXE leads it should be 5 volts dc This is the excitation voltage for the Load Cell and is regulated If the voltage is lower replace the Main PC Board refer t...

Page 22: ...te the scale in the next procedure to verify if the Main PC Board is good or bad 2 8 2 2 Calibration Test This test calibrates the scale using the simulator and can verify that the Main PC Board is fu...

Page 23: ...ce depends upon the type of use of the scale If left connected to the AC Adapter all of the time the battery receives a small charge when the battery voltage is low service life can be many years The...

Page 24: ...CHAPTER 2 DIAGNOSIS Ohaus Corporation www ohaus com 2 12 EB Series Scales Series Service Manual...

Page 25: ...m the scale by disconnecting the AC adapter Make sure the scale is off 2 Carefully lift and remove the Pan and Pan Support from the scale 3 Turn the scale over and remove the screws which hold the Top...

Page 26: ...d to gain access to the switch connections 1 Refer to Section 3 1 and remove Top Housing CAUTION Use care in the next step as the Display PCB wiring is attached to the PCB 2 Place the scale in the upr...

Page 27: ...method is to use a flat razor blade 7 Insert the cable from the new Membrane Switch through the hole in the Top Housing Peel off the protective film from the new Membrane Switch and carefully align a...

Page 28: ...tion This is necessary to prevent damage to the circuitry and the Battery if the wiring is accidentally shorted during servicing Figure 3 5 Battery Terminal Connector Note the positioning of the cable...

Page 29: ...board is Version 2 see Figures 3 8 and 2 3 8 On the replacement Main PC Board install the Battery and Switch connectors 9 Refer to Figure 2 2 and solder the Load Cell wiring to the replacement Main PC...

Page 30: ...position See Figure 2 2 14 Position the Top Housing in place over the scale temporarily and install the Platform Support and Platform in place 15 Configure the new PCB set units capacity readability e...

Page 31: ...the Ribbon Cable from the Display PC board See Figure 3 10 Figure 3 10 Ribbon Cable from Main PCB to Display PCB 3 Disconnect the Membrane Switch Cable from the Display PCB See Figure 3 11 Figure 3 11...

Page 32: ...sts in Chapter 4 3 3 3 LCD Replacement This procedure is performed when an LCD shows signs of visible damage such as a cracked glass or partial display and the scale operates normally in all other fun...

Page 33: ...e installation 1 Refer to Section 3 1 and remove Top Housing 2 Turn the scale over and remove the four feet by unscrewing them counter clockwise The feet are actually screwed into the Load Cell Frame...

Page 34: ...from the Display PC Board to the Main PC Board 10 Install the Main PC Board into position in the slots on the Bottom Housing and secure with the screws and washers previously removed 11 If necessary o...

Page 35: ...ng can be removed by cutting the tie wrap holding the battery wires together with the Load Cell cable 3 Remove the Load Cell by unscrewing two bolts on the top of the Load Cell and two bolts on the bo...

Page 36: ...aced in the existing Load Cell frame the Overload Protection Stops must be set before calibrating or testing the scale This will require the use of mm feeler gauges ranging from 0 6 to 1 6 mm and mass...

Page 37: ...the specified mass on the Pan all of the overload down stops should hit the bottom Load Cell Frame 4 Tighten the nut on the down stop screws so they will not move and recheck TABLE 3 2 LOAD CELL OVERL...

Page 38: ...Top housing See Section 3 1 2 Disconnect the two wires from the battery See Figure 3 18 which is a close up view 3 Remove the Battery from the Bottom Housing 4 Install a replacement Battery into the s...

Page 39: ...are displayed followed by a countdown of 8 s 7 s 6 s and so on until all zeros are reached briefly followed by a software revision number This is a segment display test Figure 4 1 illustrates the sta...

Page 40: ...EATABILITY WORKSHEET n Reading Delta Reading Mean Delta x Delta 1 2 3 4 5 6 7 8 9 10 n number of Reading Mean Sum of readings 10 Delta Reading Mean Standard Deviation Square Root of sum of Delta x Del...

Page 41: ...er of the weighing surface and press the ZERO button to return the reading to zero 5 Slide the mass halfway between the center and the left edge of the pan and record the reading 6 Slide the mass to t...

Page 42: ...s ZERO 5 Add the reference mass to the center of the pan and record the exact value displayed 6 Remove the reference mass and verify that the display returns to zero If it does not disregard the readi...

Page 43: ...erence weight added at 1 4 full scale capacity ________________ Reading 3 reference weight added at 1 2 full scale capacity ________________ Reading 4 reference weight added at 3 4 full scale capacity...

Page 44: ...ation by a long press of Zero and COUNT at the same time to initiate calibration 2 The required calibration weight is displayed ex 3000g for a 3kg model At this time a different calibration weight val...

Page 45: ...n the field NOTE In all cases where a part is replaced the scale must be thoroughly checked after the replacement is made The scale MUST meet the parameters of all applicable specifications in this ma...

Page 46: ...GRAMS Ohaus Corporation www ohaus com 5 2 EB Series Scales Service Manual 5 1 Drawings and Parts Lists EB Series Parts 1 2 5 15 16 80 22 21 18 17 9 8 6 3 4 7 10 12 11 14 20 13 19 Figure 5 1 EB Series...

Page 47: ...Use Cover 5 Back Overlay 6 Membrane Switch 7 Top Housing 8a LCD 8b Backlight 9 Display PCB 10 Top Load Cell Frame 11 Display PCB Cable 12 Load Cell Assembly 13 Load Cell 14 Bottom Load Cell Frame 15...

Page 48: ...CHAPTER 5 PARTS LISTS DIAGRAMS Ohaus Corporation www ohaus com 5 4 EB Series Scales Service Manual...

Page 49: ...s and hold the TARE COUNT and ZERO buttons simultaneously while the display is counting down Release when either 0 0 or xx000 is displayed Notes If the PCB has calibration data the display will indica...

Page 50: ...splayed weight wait until display shows second weight to add 2 3 of capacity 3 Add displayed weight wait until display shows third weight to add full capacity 4 After accepting the weight the scale wi...

Page 51: ...table TABLE A 1 SCALE RESOLUTION SETTINGS MODEL RESOLUTION CAPACITY EB3 30000 3000 0 EB6 60000 6000 0 EB15 15000 15000 0 EB30 30000 30000 2 When the correct value is displayed press the TARE button t...

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Page 53: ...80251392 P N 80251392 D SERVICE MANUAL EB SERIES SCALES...

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