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.
Builders who report a missing piece often find it in one of these places. Tick each one off as you look.
Look-alike colors in this set
These parts appear in this set in two colors that are easy to confuse. If you are one short in one color,
check whether it went in where the other color belongs. Each color has its own element ID in the parts list
at the back of the instructions.
Technic Axle and Pin Connector PerpendicularBlack ×8Dark Blue ×22Black is yellower and darker than Dark Blue.
Technic Axle and Pin Connector Perpendicular Double Split [Reinforced]Black ×2Dark Blue ×6Black is yellower and darker than Dark Blue.
Technic Beam 1 x 15 ThickBlack ×1Dark Blue ×2Black is yellower and darker than Dark Blue.
Technic Beam 1 x 2 Thick with Pin Hole and Axle HoleBlack ×25Dark Blue ×24Black is yellower and darker than Dark Blue.
Technic Beam 1 x 3 ThickBlack ×4Dark Blue ×8Black is yellower and darker than Dark Blue.
Technic Beam 1 x 7 ThickBlack ×6Dark Blue ×2Black is yellower and darker than Dark Blue.
13 more look-alike pairs
Technic Beam 1 x 9 ThickBlack ×4Dark Blue ×3Black is yellower and darker than Dark Blue.
Technic Beam 2 x 4 L-Shape ThickBlack ×14Dark Blue ×9Black is yellower and darker than Dark Blue.
Technic Panel Fairing #21 5L Small Smooth, Side BBlack ×3Dark Blue ×6Black is yellower and darker than Dark Blue.
Technic Panel Fairing #22 5L Small Smooth, Side ABlack ×2Dark Blue ×6Black is yellower and darker than Dark Blue.
Technic Panel Fairing #7 3L Very Small Smooth, Side ABlack ×4Dark Blue ×5Black is yellower and darker than Dark Blue.
Technic Panel Fairing #8 3L Very Small Smooth, Side BBlack ×3Dark Blue ×5Black is yellower and darker than Dark Blue.
Technic Panel Fairing 2 x 1 x 1Black ×1Dark Blue ×3Black is yellower and darker than Dark Blue.
Technic Panel Fairing 2 x 3 x 1Black ×10Dark Blue ×14Black is yellower and darker than Dark Blue.
Technic Pin Connector Hub with 1 Pin with Friction Ridges Lengthwise [Centered Friction Ridge]Black ×12Dark Blue ×25Black is yellower and darker than Dark Blue.
Tile 1 x 4 with GrooveBlack ×2Dark Blue ×1Black is yellower and darker than Dark Blue.
Technic Beam 1 x 15 ThickBlack ×1Dark Bluish Gray ×2Black is darker than Dark Bluish Gray.
Technic Beam 1 x 9 ThickBlack ×4Dark Bluish Gray ×1Black is darker than Dark Bluish Gray.
Technic Pin Connector Hub with 2 AxlesBlack ×1Dark Bluish Gray ×4Black is darker than Dark Bluish Gray.
Technic Beam 1 x 3 ThickWhitePart 32523Element 6632140 or 4208160×2
Technic Beam 1 x 7 ThickWhitePart 32524Element 6564912 or 6318056×5
Technic Beam 2 x 4 L-Shape ThickWhitePart 32140Element 6271824 or 4118980×2
Technic Bush 1/2 Smooth with Axle Hole Semi-ReducedWhitePart 32123bElement 6634562 or 63602631 spare in the box×17
Technic Panel Fairing 2 x 3 x 1WhitePart 71682Element 6334548×2
Technic Pin 1/2 without Friction RidgesWhitePart 4274Element 6552190 or 63880181 spare in the box×5
Technic Pin Connector Round 1L [Beam]WhitePart 18654Element 6550155 or 61771141 spare in the box×12
Tile 1 x 6 with GrooveWhitePart 6636Element 6548296 or 663601×1
Tile 2 x 3WhitePart 26603Element 6552162 or 6550161×1
Tan
19 pieces
Technic Engine Crankshaft CenterTanPart 2854Element 6355727 or 6013937×2
Technic Gear 12 Tooth BevelTanPart 6589Element 4565452 or 4514556×4
Technic Gear 20 Tooth Double Bevel with Axle Hole Type 1 [+ Opening]TanPart 18575Element 6346517 or 6084724×2
Technic Pin 3/4TanPart 32002Element 6663097 or 60139381 spare in the box×5
Technic Pin Long without Friction Ridges, with Anti-Roll NotchTanPart 39888Element 6321305×6
Reddish Brown
13 pieces
Technic Axle 3 with StopReddish BrownPart 24316Element 6135494×6
Technic Axle 5 with StopReddish BrownPart 15462Element 6159763×7
Yellow
11 pieces
Technic Axle 5YellowPart 32073Element 6130008×2
Technic Axle 7YellowPart 44294Element 6130009×1
Technic Engine CrankshaftYellowPart 2853Element 6640378 or 4119474×2
Technic Engine Piston RoundYellowPart 2851Element 4112203 or 285124×6
Trans-Clear
8 pieces
Technic Engine Cylinder without Side Slots, with Bottom SlotsTrans-ClearPart 2850bElement 6514435 or 6353017×6
Technic Panel Round Corner 5 x 3 x 2 Left with Blue/Dark Bluish Grey Headlight PrintTrans-ClearPart 2438pr0001Element 6499723 or 6426365×1
Technic Panel Round Corner 5 x 3 x 2 Right with Blue/Dark Bluish Grey Headlight PrintTrans-ClearPart 2442pr0001Element 6499851 or 6426366×1
Medium Blue
2 pieces
Bracket 1 x 1 - 1 x 1Medium BluePart 36841Element 6248079 or 6236112×2
Trans-Red
2 pieces
Dish 2 x 2 Inverted [Radar]Trans-RedPart 4740Element 6580377 or 6245303×2
Dark Tan
1 piece
Large Figure Weapon Lightsaber Hilt with Axle Hole and Two Bar HoldersDark TanPart 24122Element 6311435×1
Glow in Dark White
1 piece
Bar 4L (Lightsaber Blade / Wand)Glow in Dark WhitePart 30374Element 6384681 or 6009094×1
Lime
1 piece
Technic Beam 1 x 2 ThickLimePart 43857Element 6149993 or 4263119×1
[No Color/Any Color]
1 piece
Sticker Sheet for Set 42154-1[No Color/Any Color]Part 10101056Element 6415921×1
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.
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.