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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.

Sonar Transmitting Cruiser

Checking

6783 Sonar Transmitting Cruiser

329 pieces in 100 part and color combinations, plus 3 minifigures.

LEGO counts 363 pieces. This inventory comes from a separate parts catalog and lists 348, including the 19 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

White 221 pieces

  • Battery Box, 9V Small [Complete Assembly] White Part 4760c01 ×1
  • Bracket 2 x 2 - 2 x 2 White Part 3956 Element 6313593 or 395601 ×1
  • Brick 1 x 1 White Part 3005 Element 6552096 or 6548258 ×12
  • Brick 1 x 2 White Part 3004 Element 6548257 or 4613964 ×10
  • Brick 1 x 3 White Part 3622 Element 6550143 or 362201 ×2
  • Brick 1 x 4 with Black 15 Bars Grill Print White Part 3010apr0004 ×2
  • Brick 1 x 4 with Bottom Tubes, Lowered Center Cross Support White Part 3010a ×3
  • Brick 1 x 6 with Bottom Tubes and 2 Lowered Cross Supports White Part 3009b ×3
  • Brick 2 x 2 without Inside Ridges White Part 3003a ×8
  • Brick 2 x 3 White Part 3002 Element 6550133 or 300251 ×3
  • Brick Sloped 45° 2 x 1 with Bottom Pin White Part 3040b Element 6552115 or 4121932 ×3
  • Brick Sloped 45° 2 x 1 with Bottom pin, with Orange Microphone Print White Part 3040bpr0009 ×2
  • Brick Sloped 45° 2 x 2 with 12 Buttons, 3 Red Lamps, Black Panel Print White Part 3039pr9996 ×1
  • Brick Sloped 45° 2 x 2 with Black Grill Print White Part 3039pr0009 Element 6271990 or 4174745 ×1
  • Brick Sloped 45° 2 x 2 with Computer Screen Print White Part 3039pr0026 Element 80261 ×2
  • Brick Sloped Inverted 45° 2 x 2 [Ovoid Bottom Pin, Bar-sized Stud Holes] White Part 3660 Element 366001 ×2
  • Brick Special 1 x 1 with Headlight White Part 4070 Element 6548267 or 407001 ×4
  • Brick Special 2 x 2 with Pin and No Axle Hole White Part 4730 ×7
  • Brick Wedged, Sloped 4 x 4 Taper with Classic Space Print White Part 4858pr0003 ×1
  • Brick Wedged, Sloped Inverted 6 x 4 with 2 Stud Connections White Part 4856a ×1
  • Engine Smooth Large, Cone Back [1 x 2 Thin Top Plate] White Part 4868a Element 4175427 ×2
  • Equipment Control Panel White Part 2342 ×1
  • Fence Lattice 1 x 4 x 1 White Part 3633 Element 4550171 or 363301 ×2
  • Hinge Brick 1 x 2 Base White Part 3937 Element 6619287 or 393701 ×1
  • Hinge Brick 1 x 2 Top Plate Thin White Part 3938 Element 393801 ×1
  • Hinge Plate 2 x 5 with Large Hole [Complete Assembly] White Part 3149bc01 ×1
  • Hinge Tile 1 x 4 White Part 4625 Element 4264365 or 4258048 ×2
  • Hinge Vehicle Roof Holder 1 x 4 White Part 4315 Element 4214079 or 4190507 ×1
  • Light Brick 1 x 2 [Single Bulb] White Part 4767 Element 73666 ×2
  • Light Brick 1 x 4 [Two Bulbs] White Part 4771 ×1
  • Panel 3 x 3 x 6 Corner Wall White Part 2345 Element 234501 ×8
  • Plate 1 x 1 White Part 3024 Element 6548262 or 302401 ×8
  • Plate 1 x 2 White Part 3023 Element 6552100 or 6548261 ×14
  • Plate 1 x 3 White Part 3623 Element 6552105 or 6550144 ×2
  • Plate 1 x 4 White Part 3710 Element 6552108 or 6548266 ×4
  • Plate 1 x 6 White Part 3666 Element 6552107 or 6548265 ×4
  • Plate 1 x 8 White Part 3460 Element 6550141 or 346001 ×3
  • Plate 2 x 10 White Part 3832 Element 6552109 or 383201 ×1
  • Plate 2 x 2 White Part 3022 Element 6552099 or 6548260 ×15
  • Plate 2 x 3 White Part 3021 Element 6550136 or 302101 ×17
  • Plate 2 x 4 White Part 3020 Element 6552098 or 302001 ×5
  • Plate 2 x 4 with Electric Contacts White Part 4757 Element 475701 or 73534 ×2
  • Plate 2 x 6 White Part 3795 Element 6550146 or 379501 ×8
  • Plate 2 x 8 White Part 3034 Element 6552101 or 303401 ×1
  • Plate 2 x 8 with Electric Contacts White Part 4758 Element 475801 or 73535 ×3
  • Plate Special 1 x 1 with Clip Vertical [Thin U Clip] White Part 4085b Element 4542191 ×10
  • Plate Special 1 x 2 with 1 Stud without Groove (Jumper) White Part 3794a ×3
  • Sound Brick, Round, 9V 2 x 2 x 1 1/3 with Two Space Noises White Part 4774c02 ×1
  • Support 2 x 4 x 5 Stanchion Inclined [5mm wide posts] White Part 4476b Element 4142125 or 447601 ×2
  • Technic Brick 1 x 2 [1 Pin Hole] White Part 3700 Element 6619284 or 370001 ×7
  • Tile 1 x 2 with Arrow Long Yellow with Black Border Print White Part 3069bpr0023 Element 80533 ×6
  • Tile 1 x 2 with Black Grill Print White Part 3069bpr0022 ×4
  • Tile 1 x 2 with Groove White Part 3069b Element 6548264 or 306901 ×1
  • Tile 2 x 2 with Arrow Thin Yellow with Black Border Print White Part 3068bpr0032 ×2
  • Tile 2 x 2 with Grill Black Print White Part 3068bpr0031 ×2
  • Tile 2 x 2 with Groove White Part 3068b Element 6548263 or 306801 ×2
  • Wedge Plate 3 x 4 without Stud Notches White Part 4859 Element 4215973 or 4199395 ×1
  • Wedge Plate 4 x 4 Wing Left White Part 3936 Element 4280155 or 4200492 ×1
  • Wedge Plate 4 x 4 Wing Right White Part 3935 Element 4280154 or 4200491 ×1

Black 80 pieces

  • Bar 1 x 3 [Clip / Anti-Stud] Black Part 4735 Element 4141580 or 473576 ×1
  • Bracket 8 x 2 x 1 1/3 Black Part 4732 Element 473226 ×2
  • Brick 2 x 3 without Cross Supports Black Part 3002a ×2
  • Brick Round 2 x 2 with Axle Hole Black Part 3941 Element 614376 or 614326 ×2
  • Brick Sloped Inverted 33° 3 x 2, No Connections between Studs, Ovoid Bottom Pin Black Part 3747a ×2
  • Brick Special 1 x 1 with 3 Speakers / Loudspeakers / Space Positioning Rockets Black Part 3963 Element 4200791 or 396326 ×1
  • Brick Special 1 x 2 x 2/3 with Studs on Sides Black Part 4595 Element 6681661 or 4523339 ×4
  • Cone 1 x 1 [No Top Groove] Black Part 4589 Element 4518219 or 458926 ×4
  • Cone 4 x 4 x 2, Axle Hole [Plain] Black Part 3943b Element 4143243 or 394326 ×1
  • Dish 6 x 6 Inverted, Radar / Webbed [No Anti-studs] Black Part 4285a ×2
  • Equipment Control Panel Black Part 2342 Element 4164402 or 234226 ×3
  • Equipment Radio [Compact Handle] Black Part 3962a ×1
  • Flexible Hose 8.5L with Tabless Ends (Ends same color as Tube) Black Part 73590c01a ×6
  • Hinge Vehicle Roof Holder 1 x 4 Black Part 4315 Element 4250225 or 431576 ×4
  • Lever Small Base with Black Lever Black Part 298c02 Element 73587 ×5
  • Plate 1 x 2 Black Part 3023 Element 302326 ×8
  • Plate 1 x 6 Black Part 3666 Element 366626 ×2
  • Plate 2 x 4 Black Part 3020 Element 302026 ×3
  • Plate 4 x 4 Black Part 3031 Element 4243819 or 303126 ×1
  • Plate 6 x 8 Black Part 3036 Element 303676 or 303626 ×2
  • Plate Round 2 x 2 with Axle Hole Type 1 (+ Opening) Black Part 4032a Element 403226 ×2
  • Plate Special 1 x 2 with Handles [Flat Ends / Low Attachment] Black Part 3839b Element 383926 ×1
  • Plate Special 1 x 4 Offset with Bar Holes Black Part 4590 Element 6002559 or 4278029 ×8
  • Plate Special 2 x 2 with Wheels Red Black Part 122c01 ×2
  • Tool Screwdriver and Spanner / Wrench Black Part 4006 Element 6034000 or 4569095 ×1
  • Weapon Gun / Torch (Space) [with Grooves] Black Part 3959 Element 4254942 or 395976 ×1
  • Wedge Plate 3 x 4 without Stud Notches Black Part 4859 ×1
  • Wheel Balloon with Axle hole Black Part 4288 Element 4113076 or 428876 ×4
  • Windscreen 6 x 4 x 2 Canopy Black Part 4474 Element 4114239 or 447426 ×2
  • Wing, Tail 4 x 1 x 3 Black Part 2340 Element 6591863 or 4651541 ×2

Trans-Red 15 pieces

  • Antenna 1 x 4 with Rounded Top Trans-Red Part 3957a Element 6065498 or 4106520 ×2
  • Brick Round 1 x 1 with Fins, Open Stud Trans-Red Part 4588 Element 458841 ×2
  • Brick Round 1 x 1 x 2/3 Light Bulb Cover Trans-Red Part 4770 Element 4226863 or 477041 ×2
  • Cone 1 x 1 [No Top Groove] Trans-Red Part 4589 Element 618841 ×3
  • Dish 2 x 2 Inverted [Radar] Trans-Red Part 4740 Element 6580377 or 6245303 ×1
  • Plate 1 x 1 Trans-Red Part 3024 Element 6513963 or 6252042 ×5

Trans-Green 6 pieces

  • Brick Round 1 x 1 x 2/3 Light Bulb Cover Trans-Green Part 4770 Element 477048 ×2
  • Plate 1 x 1 Trans-Green Part 3024 Element 6513967 or 6252046 ×4

Trans-Dark Blue 5 pieces

  • Hinge Vehicle Roof 4 x 4 Trans-Dark Blue Part 4213 Element 3000143 ×2
  • Windscreen 6 x 4 x 2 Canopy Trans-Dark Blue Part 4474 Element 3006643 ×3

Trans-Yellow 2 pieces

  • Plate 1 x 1 Trans-Yellow Part 3024 Element 6513966 or 6252045 ×2

Minifigures 3 figures

  • Classic Spaceman, Yellow with Airtanks (3842b Helmet) Minifigure, checked as a whole figure ×1
  • Classic Spaceman, Red with Airtanks (3842b Helmet) Minifigure, checked as a whole figure ×1
  • Classic Space Droid - Blue, Round Base 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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