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LEGO Missing Piece Checker

Rule out the usual hiding places first. If the piece really is gone, check the set piece by piece and leave with the element ID LEGO asks for, or a link to buy the part.

Control System Building Set

Checking

9702 Control System Building Set

222 pieces in 74 part and color combinations, plus 2 minifigures.

LEGO counts 221 pieces. This inventory comes from a separate parts catalog and lists 230, including the 8 parts inside the minifigures; the two do not always count the same elements, so their totals differ. Spare parts are counted in neither figure.

Before you call it missing

Builders who report a missing piece often find it in one of these places. Tick each one off as you look.

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Piece checklist

Yellow 67 pieces

  • Plate 1 x 10 Yellow Part 4477 Element 6079138 or 6078095 ×4
  • Plate 1 x 2 Yellow Part 3023 Element 302324 ×12
  • Plate 1 x 3 Yellow Part 3623 Element 362324 ×4
  • Plate 1 x 4 Yellow Part 3710 Element 371024 ×8
  • Plate 1 x 6 Yellow Part 3666 Element 366624 ×4
  • Plate 1 x 8 Yellow Part 3460 Element 346024 ×5
  • Plate 2 x 2 Yellow Part 3022 Element 4613978 or 302224 ×2
  • Plate 2 x 2 Corner Yellow Part 2420 Element 242074 or 242024 ×6
  • Plate 2 x 3 Yellow Part 3021 Element 302124 ×2
  • Plate 2 x 6 Yellow Part 3795 Element 379524 ×2
  • Plate 6 x 10 Yellow Part 3033 Element 303324 ×1
  • Plate Round 2 x 2 with Axle Hole Type 1 (+ Opening) Yellow Part 4032a Element 403224 ×2
  • Plate Special 1 x 2 with 1 Stud without Groove (Jumper) Yellow Part 3794a ×4
  • Technic Plate 2 x 4 [3 Holes] Yellow Part 3709 Element 370924 ×2
  • Technic Plate 2 x 8 [7 Holes] Yellow Part 3738 Element 4624216 or 373824 ×4
  • Tile 1 x 2 with Groove Yellow Part 3069b Element 306924 ×2
  • Tile 1 x 8 with Groove Yellow Part 4162 Element 6388482 or 4189400 ×3

Red 52 pieces

  • Brick 1 x 2 Red Part 3004 Element 4613961 or 300421 ×10
  • Brick 2 x 2 Red Part 3003 Element 4103590 or 300371 ×2
  • Brick 2 x 4 Red Part 3001 Element 300121 ×1
  • Brick Sloped 45° 2 x 1 with Bottom Pin Red Part 3040b Element 4121934 or 304021 ×2
  • Storage Bin, Dacta, Small Red Part upn0032 ×1
  • Technic Brick 1 x 10 [9 Pin Holes] Red Part 2730 Element 273021 ×6
  • Technic Brick 1 x 12 [11 Pin Holes] Red Part 3895 Element 389521 ×4
  • Technic Brick 1 x 16 [15 Pin Holes] Red Part 3703 Element 370321 ×4
  • Technic Brick 1 x 2 [1 Pin Hole] Red Part 3700 Element 370021 ×6
  • Technic Brick 1 x 4 [3 Pin Holes] Red Part 3701 Element 370121 ×6
  • Technic Brick 1 x 6 [5 Pin Holes] Red Part 3894 Element 389421 ×4
  • Technic Brick 1 x 8 [7 Pin Holes] Red Part 3702 Element 370221 ×6

Light Gray 47 pieces

  • Baseplate 16 x 32 Light Gray Part 3857 Element 4219612 or 274802 ×1
  • Motor, 9V 5 x 4 x 2 1/3, Dark Gray Bottom Light Gray Part 2838c01 Element 4494210 or 74569 ×1
  • Technic Axle Connector Ridged [with + Hole + Orientation] Light Gray Part 6538a ×1
  • Technic Axle Pin without Friction Ridges Lengthwise Light Gray Part 3749 Element 4184168 or 4154179 ×4
  • Technic Axle and Pin Connector Light Gray Part 3651 Element 4105243 or 365102 ×4
  • Technic Beam 1 x 4 Thin with Stud Connector Light Gray Part 2825 Element 4107133 or 282502 ×2
  • Technic Bush Light Gray Part 3713 Element 4125313 or 659002 ×6
  • Technic Bush 1/2 Toothed Type II [X Opening] Light Gray Part 4265b Element 4100501 or 657702 ×6
  • Technic Gear 14 Tooth Bevel Light Gray Part 4143 Element 414352 or 414302 ×2
  • Technic Gear 24 Tooth Crown with Reinforcements [New Style] Light Gray Part 3650c Element 365002 ×1
  • Technic Gear 24 Tooth [Old Style - Three axle holes] Light Gray Part 3648a ×2
  • Technic Gear 40 Tooth Light Gray Part 3649 Element 364902 ×1
  • Technic Gear 8 Tooth Light Gray Part 3647 Element 364702 ×2
  • Technic Pin without Friction Ridges Lengthwise Light Gray Part 3673 Element 4184166 or 367302 ×6
  • Technic Wedge Belt Wheel [aka Pulley] Light Gray Part 4185 Element 4100502 or 418502 ×6
  • Technic Worm Gear Light Gray Part 4716 Element 471602 ×1
  • Wheel with Split Axle hole Light Gray Part 3482 Element 348202 ×1

Black 39 pieces

  • Pen with Technic Print Black Part upn0233 ×1
  • Rubber Band Small 13mm (Square Cross Section) Black Part 71509 Element 4141606 or 4107153 ×1
  • Sound Brick, Round, 9V 2 x 2 x 1 1/3 with Two Town Police Noises Black Part 4774c01 ×1
  • String Cord Medium Thickness 50cm Black Part 7916c50 ×2
  • Technic Axle 10 Black Part 3737 Element 373726 ×2
  • Technic Axle 3 Black Part 4519 Element 6238084 or 451926 ×2
  • Technic Axle 4 Black Part 3705 Element 370526 ×2
  • Technic Axle 6 Black Part 3706 Element 370626 ×3
  • Technic Axle 8 Black Part 3707 Element 370726 ×2
  • Technic Pin with Friction Ridges Lengthwise and Center Slots Black Part 2780 Element 4121715 or 278026 ×14
  • Technic Wedge Belt Wheel Tire Black Part 2815 Element 6028041 or 281526 ×4
  • Tyre Offset Tread 24 x 8 Black Part 3483 Element 4501048 or 348326 ×1
  • Wire with Brick 2 x 2 x 2/3 Pair, 15L Black Part 5306bc015 Element 75565 ×1
  • Wire with Brick 2 x 2 x 2/3 Pair, 162L Black Part 5306bc162 Element 75656 ×3

White 8 pieces

  • Light Brick 1 x 2 with Single Side Light White Part 6035 Element 4603220 or 74880 ×1
  • Plate 2 x 8 with Electric Contacts White Part 4758 Element 475801 or 73535 ×1
  • Technic Cable Holder White Part 70376 Element 70376 ×3
  • Technic Rubber Belt Medium [24mm ID] [Round Cross Section] White Part 85544 Element 70713 ×1
  • Technic Rubber Belt Medium [26mm ID] [Round Cross Section] White Part 85545 Element 70714 ×2

[No Color/Any Color] 5 pieces

  • Activity Booklet, Dinosaur - Set 9702 [No Color/Any Color] Part 9702b4 ×1
  • Activity Booklet, Elevator - Set 9702 [No Color/Any Color] Part 9702b2 ×1
  • Activity Booklet, Motorized Turntable - Set 9702 [No Color/Any Color] Part 9702b1 ×1
  • Activity Booklet, Road Painting Vehicle - Set 9702 [No Color/Any Color] Part 9702b3 ×1
  • Activity Card, Cover & Inventory Card, Set 9702 [No Color/Any Color] Part 9702b0 ×1

Trans-Clear 2 pieces

  • Storage / Sorting Tray, Dacta, 13 Compartment for Dacta Small Bin Trans-Clear Part 167915 ×1
  • Storage Bin Lid, Dacta, 19 x 24 Trans-Clear Part 71082 ×1

Chrome Silver 1 piece

  • Dish 2 x 2 x 2/3 Light Reflector Chrome Silver Part 71128 Element 71128 ×1

Trans-Green 1 piece

  • Brick 1 x 2 without Bottom Tube Trans-Green Part 3065 Element 6514266 or 6244908 ×1

Minifigures 2 figures

  • Man, Black Overalls, Red Cap (3626b Head) Minifigure, checked as a whole figure ×1
  • Woman, White Top with Red Necklace, Blue Legs, Black Hair (3626b Head) Minifigure, checked as a whole figure ×1

Tick each piece as you find it, or mark it missing.

When a piece really is missing

Ask LEGO

LEGO takes requests for pieces missing from a new set through its customer service site. The form asks for the set number and each piece's element ID, the number printed beside the piece in the parts list at the back of the instructions. This checker lists both.

Request a replacement from LEGO

Buy the piece

Mark a piece missing and your list links it to an eBay search for that part, which also covers pieces from older or second-hand sets.

Keep a record

Copy or download your missing list (the CSV opens in any spreadsheet), or print the whole checklist and tick pieces off on paper. Your marks stay in this browser, so you can check a big set over several sittings.

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