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MHB31

HYBRID PIANO

N3, N2, N1

NU1

MAINTENANCE HANDBOOK

September 2012  Ver.1

Summary of Contents for NU1

Page 1: ...MHB31 HYBRID PIANO N3 N2 N1 NU1 MAINTENANCE HANDBOOK September 2012 Ver 1 ...

Page 2: ...ADJUSTMENT POINTS STANDARD DIMENSIONS 5 KEY SENSOR MEASUREMENT SENSOR HEIGHT ADJUSTMENT 6 N1 AND NU1 KEY SHUTTER INSTALLATION PROCEDURE 10 EXTERNAL PART FINISHING LIST 11 N3 PARTS LIST 12 N2 PARTS LIST 13 N1 PARTS LIST 14 NU1 PARTS LIST 15 N3 DISASSEMBLY PROCEDURE 16 N2 DISASSEMBLY PROCEDURE 20 N1 DISASSEMBLY PROCEDURE 24 NU1 DISASSEMBLY PROCEDURE 27 N3 N2 KEY COVER ASSEMBLY REPLACEMENT PROCEDURE ...

Page 3: ...e hands when removing or installing it Touching it with bare hands will cause fingerprint stains and debris to adhere and possibly cause faulty operation N3 N2 N1 During assembly Never remove the center rails N3 N2 During assembly disassembly Be careful not to bend the angle of hardware for the TW speaker or crush or dent the TW speaker itself N3 N2 Other The upper unit and lower unit on the N1 ea...

Page 4: ...mbly Check and set the DIP switches on the board when replacing the DM circuit board and always execute the factory set of the test program N3 N2 N1 NU1 During disassembly Never remove the NU1 side boards and arms NU1 Side board L Arm L Side board R Arm R ...

Page 5: ...64 Above 1 mm Above 1 mm Hammer stop 12 mm Use a ruler or scale to measure the distance in standard units from the top of the hammer head with the hammer shank lightly contacting the cushioning material to the top of the hammer head when caught by the back check after tapping the key Space is limited here so after finding the dimensions remove the hammer sensor unit and shank stopper if necessary ...

Page 6: ...ND Position when the keyboard is lightly pressed to the bottom of the key K1 K2 K3 K4 Four threshold values between the REST position and END position when a key is pressed While the value of the END is 10 mm the threshold values are K1 2 7 mm K2 4 5 mm K3 6 3 mm and K4 8 1 mm M1 M2 Two threshold values between the REST position and END position when a hammer is in motion The distance between the ...

Page 7: ... screw Hammer sensor adjustment gear Locking screw Loosen the hammer sensor adjustment gear and loosen the locking screw Adjust the height with the hammer sensor adjustment gear Tighten the locking screw and then tighten the hammer sensor adjustment gear Adjustment procedure 1 2 3 Hammer sensor adjustment gear Locking screw On the N1 and NU1 there is no need to adjust the key sensor unit height Th...

Page 8: ...surement mode operating procedures All key measurement mode N3 N2 N1 10 F 0 12 G 0 14 A 0 POWER ON release key after about 7 seconds NU1 DEMO SONG PLAY STOP POWER ON 1 key measurement mode N3 N2 N1 9 F0 11 G0 POWER ON release key after about 7 seconds NU1 DEMO SONG PIANO VOICE PLAY STOP POWER ON Content Task Description N3 N2 N1 Operating guide tones N3 N2 N1 Task Description NU1 Screen display NU...

Page 9: ... and an operating guide appears on the panel LED screen If measurement fails then the 78 D4 and 76 C4 keys are trilled and the tone for the applicable error key is generated NU1 key no displayed Key sensor test mode N3 N2 N1 NU1 Hammer sensor test mode N3 N2 N1 Sensor test mode Content Task Description N3 N2 N1 Operating guide tones N3 N2 N1 Task Description NU1 Screen display NU1 1 Refer to start...

Page 10: ...placing the keys repeatedly tap and release each key several times and check that the key shutter does not bind on the key sensor bracket 8 Execute the maintenance program Key Measurement Make sure to inspect that the key works properly using the key sensor test mode Place at even intervals Place at even intervals Photo 3 N1 Photo 4 N1 Photo 5 N1 Photo 5 NU1 Photo 3 NU1 Photo 4 NU1 Photo 1 N1 Phot...

Page 11: ...VER Polyester coating KEY BLOCK Polyester coating LEG FRONT REAR Melamine baking finish PEDAL UNIT Polyester coating N2 Part Surface treatment types TOP BOARD REAR Polyester coating TOP BOARD FRONT Polyester coating FRONT TOP RAIL Polyester coating MUSIC REST Polyester coating MUSIC SHELF Acrylic urethane coating FRONT RAIL Polyester coating KEY COVER Polyester coating KEY BLOCK Polyester coating ...

Page 12: ...NIT L WQ256200 For SOFT PEDAL PEDAL LEVER UNIT R WQ256300 For DAMPER PEDAL Interior KEY ASSEMBLY KEY 1 WR824800 With shutter KEY ASSEMBLY KEY 88 WR833500 With shutter HAMMER SHANK ASSEMBLY A1 WR822400 K1 K8 All come with shutter HAMMER SHANK ASSEMBLY A2 WR822500 K9 K16 HAMMER SHANK ASSEMBLY A3 WR822600 K17 K24 HAMMER SHANK ASSEMBLY A4 WR822700 K25 K32 HAMMER SHANK ASSEMBLY A5 WR822800 K33 K40 HAMM...

Page 13: ...Y ASSEMBLY Key 1 WR824800 With shutter KEY ASSEMBLY Key 88 WR833500 With shutter HAMMER SHANK ASSEMBLY A1 WR822400 K1 K8 The following all come with hammer shutter HAMMER SHANK ASSEMBLY A2 WR822500 K9 K16 HAMMER SHANK ASSEMBLY A3 WR822600 K17 K24 HAMMER SHANK ASSEMBLY A4 WR822700 K25 K32 HAMMER SHANK ASSEMBLY A5 WR822800 K33 K40 HAMMER SHANK ASSEMBLY A6 WR822900 K41 K48 HAMMER SHANK ASSEMBLY A7 WR...

Page 14: ...d with shutter KEY ASSEMBLY KEY 88 WW691800 Replacement set comes packed with shutter HAMMER SHANK ASSEMBLY A1 WW691900 K1 K8 All come with shutter HAMMER SHANK ASSEMBLY A2 WW692000 K9 K16 HAMMER SHANK ASSEMBLY A3 WW692100 K17 K24 HAMMER SHANK ASSEMBLY A4 WW692200 K25 K32 HAMMER SHANK ASSEMBLY A5 WW692300 K33 K40 HAMMER SHANK ASSEMBLY A6 WW692400 K41 K48 HAMMER SHANK ASSEMBLY A7 WW692500 K49 K56 H...

Page 15: ...51600 LEG ASSEMBLY L WZ082800 LEG ASSEMBLY R WZ082900 FRONT LEG SUPPORT RAIL WZ058500 FRONT LEG SUPPORT RAIL ANGLE L WZ127500 FRONT LEG SUPPORT RAIL ANGLE R WZ127600 PEDAL ASSEMBLY WZ799800 PEDAL ADJUSTER WF05450R Interior KEY ASSEMBLY KEY 1 ZC133400 Replacement set comes packed with shutter KEY ASSEMBLY KEY 88 ZC142100 Replacement set comes packed with shutter HAMMER BUTT ASSEMBLY A1 ZC142200 K1 ...

Page 16: ...ront Top Rail 2 1 Remove the music shelf L R Remove the two left right screws 88A and remove the music shelf 2 2 Remove the front top rail Remove the left right screws 78A one each grip and raise the front top rail and the remove it towards yourself 3 Music Rest 3 1 Remove the four 4 screws marked 78B CENTER RAIL MUSIC SHELF L 88A FRONT TOP RAIL MUSIC SHELF L MUSIC SHELF R 88A 78A 88A 78A FRONT TO...

Page 17: ...and remove the middle board towards you Top view Front view Front side Back side HINGE MUSIC REST YDA3 CN202 YDA3 DM 88B 88B Middle board Middle board The following is another way for removing the music rest Shift the stay assembly as shown in the figure below from the music rest guide to remove the music rest WARNING Applying too much force while rotating it at this time may cause the hinge to br...

Page 18: ...3 CN12 CN11 CN10 CN2 CN1 CN1 CN1 REB1 ACDC REB1 Top view 6 2 How to remove Sheet Box 6 2 1 Remove the music shelf angles L R Remove the screw marked 78D and loosen the screw marked 78E The music shelf angles L R can then be removed toward you 6 2 2 Remove the music rest guide Remove the three 3 screws marked 78F The music rest guide can then be removed 6 2 3 Remove each connector total of 12 locat...

Page 19: ...and remove the middle board bracket 10 2 Remove the action bracket Remove the action bracket installation screws and remove the action while gripping the lower sound part of the shank stopper and the next high sound part of the shank rail as shown in the photo right 11 Shank Stopper Remove a total of 6 screws at the four locations in the photos and remove the shank stopper 12 Hammer Sensor Unit Re...

Page 20: ...d B guide and open the top board B guide 2 3 Remove the SP grill Grip the SP grill from the rear side and pull upward to remove the fastening tape lift and remove CENTER RAIL TOP BOARD B GUIDE TOP BOARD B MUSIC REST TOP BOARD STICK Transfer pathway of the top board stick Outside Inside TOP BOARD B GUIDE TOP BOARD STICK Shifting the top board support within the guide as shown by the arrow in the fi...

Page 21: ...onnectors secure them with cable bands so as not to interfere with servicing tasks 3 2 Remove the SP box Remove the four screws S06E and the four screws S07 in the figure on the right and remove the SP box SP BOX S07 S07 S06E S06E The photo of connectors 5 Key Block Remove the two left right screws S08 and remove the key block 4 Front Top Rail Remove the right left screws S09J one each and lift an...

Page 22: ...ector 9 Shank Stopper Remove a total of 6 screws at the four locations in the photos and remove the shank stopper 10 Hammer Sensor Unit Removal of the hammer sensor unit is the same as for the GP SG Silent 8 2 Remove the action Remove the action bracket installation screws and remove the action while gripping the lower sound part of the shank stopper and the next high sound part of the shank rail ...

Page 23: ...he Wo grill 11 2 Remove the center board assembly Remove the four front panel screws S03 and remove the center board assembly The main circuit board is now accessible See lower drawing Wo Grill L Wo Grill R S05A WO GRILL L WO GRILL R S05B CENTER BOARD S03 S03 SPEAKER WOOFER YDA3 ACDC DCDC DCDC YDD DM 3 MAD 1 MAD 2 MAD MAD 4 1 2 MAD 5 S09F x 4 S09F x 4 S06A SPEAKER WOOFER DIP switch S06A S09G x 4 S...

Page 24: ...IL The DM circuit board is now accessible for servicing etc In some cases spacers have been inserted as shown in the photo so do not forget how many spacers there are 2 Key Cover Open the key cover also called the fall board the same as on an acoustic grand piano GP raise and remove 3 Front Board 3 1 Loosen the four 4 screws marked S0A and seven 7 screws marked S2EC The protect sheet assembly can ...

Page 25: ...6 Action 6 1 Remove the two 2 screws marked 591 6 2 Remove the eight action bracket installation screws and then remove the action while gripping the shank stopper lower sound part and the shank rail next high sound side as shown in the photo right We recommend you use a screwdriver with long shaft to remove the screws for the action bracket Change the step sequence in No 6 through No 9 according ...

Page 26: ...bout the procedure to remove the protective sheet 8 Shank Stopper Remove a total of four screws on the left right at the 2 locations in the photos and remove the shank stopper 9 Hammer Sensor Unit Remove the screws C at the 4 locations shown below and remove the hammer sensor unit SHANK STOPPER HAMMER SENSOR UNIT C C C C ...

Page 27: ...ter L R 3 Uppper Board Remove the left right screws S2NA one each lift the upper board upward and remove 4 Key Cover Remove the left right screws S2NB one each open the key cover lift upward and remove When removing the screw be careful not to let the upper board drop Pay attention not to damage the arm when removing the key cover unit SIDE BOARD ASSEMBLY L SIDE BOARD ASSEMBLY R ARM ASSEMBLY L ARM...

Page 28: ...assembly by increasing or decreasing the number of damper holder spacers 7 Key Sensor 7 1 Remove all the keys Be careful not to damage the key shutters attached to the keys when installing or removing the keys 7 2 Remove the eight 8 screws marked 230 The key sensor unit can then be removed Place a mark of the key sensor unit on the keybed before removal and make sure to install it at the original ...

Page 29: ...ng tape and remove the lower front speaker grill 8 3 Remove the four 4 screws marked S22A and four 4 screws marked S2MB and lift the lower board to remove it 8 4 Removing the lower front panel allows access for replacing main electrical components such as the DM circuit board or pedal unit etc S2MA S2MA LOWER GRILLE ASSEMBLY HEXAGONAL WRENCH KEYBED B S2MB S22A S2MB S22A SPEAKER R SPEAKER L LOWER B...

Page 30: ... keys when opening closing fall board Fig 2 If there is contact then perform adjustment C Keys reflected onto key cover shall appear straight when viewed Fig 3A If not then perform adjustment D N3 Shipping criteria Angle between white keys and key cover shall be 90 1 5 0 5 N2 Shipping criteria Angle between white keys and key cover shall be 90 1 2 Required parts The task requires the usual tools t...

Page 31: ...oseness play in key cover when closed If there is looseness play then perform adjustment E N2 3 Shipping criteria Step B or C between upper edge of key cover while closed and upper edge of arm shall be 5 1 4 mm N2 3 Shipping criteria Approximate difference in step between upper edge of key cover while closed and upper edge of side shim B C shall be within 2 mm Fig 4 Fall board adjustment B C Fig 5...

Page 32: ...ail binds when opening closing the key cover after changing the rotation hardware then perform Adjustment B 3 6 Adjustment D Adjust the thickness Fig 5 A and B of the felt attached to the key block To part A the key block felt A in different thickness is applied while as needed the key block felt B is applied to part B 3 7 Adjustment E Adjust the height by changing the rubber buttons attached to t...

Page 33: ...s in the red framed section A in the photo 3 2 Dismantle the top board F and remove from the main unit Fig 1 3 3 Mount the top board F assembly dedicated service part ZE082300 over the top board B so that the attached top board F fits over it 3 4 Adjust left and right so that there is no dimensional difference between the top board F and top board B edges as aligned along the dotted yellow line B ...

Page 34: ...ard F closed select the most suitable one so that there is no more than 1 millimeter deviation in the gap between the front beam and the rubber button E 4 2 Close the top board F and check that the top board front is not unseated upwards Shipping criteria E Within 1 mm If unseated upwards then reselect the rubber as in 4 1 4 3 Securely glue each of the rubber buttons while taking care so that the ...

Page 35: ...ition within standard 8 Adjust damper holder front rear position 9 Install arm upper and front board 16 Does the key cover open properly 17 Adjust using front board rubber buttons 14 Does the key cover close properly 15 Adjust using rubber buttons on key block 13 Reattach parts 12 Adjust front board height using spacers 18 Replacement completed 10 Clearance between front board and key cover within...

Page 36: ...d S0C holding the damper angle to the key cover and adjust the width of the dampers Fig 1 3 3 Install the key cover back to the key cover and install to the main body Fig 1 4 Key cover height within standard Check the left and right end Standard 1 Make sure the red felt does not rub against keys and is not rolled up when opening the key cover Fig 2 Standard 2 Make sure the gap between the red felt...

Page 37: ...Adjustment procedure by replacing damper holder DAMPER HOLDER SPACER DAMPER HOLDER DAMPER HOLDER S16 S09 ARM ARM KEY BLOCK KEY BLOCK RUBBER BUTTON RUBBER BUTTON DAMPER HOLDER SPACER DAMPER HOLDER S16 ARM KEY BLOCK RUBBER BUTTON A A B B Top view Section A A Section B B DAMPER HOLDER S09 ARM KEY BLOCK RUBBER BUTTON DAMPER HOLDER SPACER DAMPER HOLDER SPACER 7 Key cover front rear position within stan...

Page 38: ...h the key cover closed the clearance between the front board and the key cover is not too wide and the difference between the left and right side is not too large Fig 6 Reference Standard value D at shipment 3 2 mm 3 mm difference on the left and right within 2 mm Fig 6 11 Remove parts 11 1 Remove the top board 11 2 Loosen the seven 7 screws marked S2E holding the protect cover to the front board ...

Page 39: ...e A at shipment 4 5 mm 1 mm difference on the left and right within 1 mm Fig 8 3 Determine the correct front rear position of the damper holder and tighten the screw from the arm top surface Standard 1 Make sure that with the key cover opened the gap between the back of the black keys and the front surface of the key cover is within standard Fig 9 Reference Standard value B at shipment 3 3 mm 1 7 ...

Page 40: ...ilot hole in the inner surface of the arm matching the hole on the back side of the damper holder body Pilot hole φ2 1 mm 0 1 mm depth 20 mm 5 Remove the damper holder and countersink the hole φ5 mm x 90 6 Attach the damper holder repeat step 3 for front back position alignment and tighten the screw of the damper holder 7 Perform the key cover replacement procedure step 9 Install arm upper and fro...

Page 41: ...Reference Standard value A at shipment 4 5 mm 1 mm difference on the left and right within 1 mm Fig 2 6 Remove the connector assembly from the arm lower assembly L 7 Measure the difference in level between the front of the arm lower assembly L and the front rail 8 Remove the four 4 screws marked S32 replace the arm lower assembly L and attach the connector assembly Fig 1 At this time make sure to ...

Page 42: ...13 Remove the damper holder and countersink the hole φ5 mm x 90 14 Attach the damper holder repeat step 11 for front back position alignment and tighten the screw of the damper holder 15 Install the arm upper assembly L At this time make sure the distance between the front of the arm lower assembly L and the front of the arm upper assembly L is 159 6 mm 0 5 mm Fig 5 16 Install the front board asse...

Page 43: ... assembly L never remove the back board angle from the back rail Replace the arm upper assembly L with a new service part The arm upper assembly L service part does not include back board angle The following instructions describe the replacement of the arm upper assembly L Replacement of the arm upper assembly R is performed in the same way Fig 1 159 6 mm 0 5 mm S2E S14 S14 BACK RAIL ARM LOWER ASS...

Page 44: ...a height adjust function Is this adjustment required There is normally no need to adjust the height If the key sensor unit was replaced or there is a problem with the electronic sounds being generated then adjust by using the height adjustment method Also always perform the key sensor measurement if the key sensor height was changed On the N1 and NU1 there is no need to adjust the ken sensor heigh...

Page 45: ...N2 N1 NU1 SPECS Is the keyboard action on the DGP7 DGP5 the same as on the N3 N2 They are not exactly the same The N3 and N2 have an improved action which is a modified version of that used by the DGP7 DGP5 The service part numbers on the N3 and N2 are therefore all completely different numbers N3 N2 SPECS Is the keyboard action on the N3 N2 the same as on the N1 They are not exactly the same The N...

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