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22 votes
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How to disassemble LEGO train engine base part# 28743?

Here are some disassembly pictures and tips. Tools needed: Either a precision flat-head or Philips screwdriver: There are two flat-head/Phillips hybrid screws that hold the the battery cover down. ...
Rin Rio-Oki's user avatar
  • 8,893
13 votes

Minifigure Hand broken and stuck in arm

Don't fix it I sympathize with the desire to fix it, but on closer consideration it doesn't seem easy or worth it. Getting the hand out would probably damage the arm even if you manage to do it. ...
chicks's user avatar
  • 5,275
11 votes
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Old RCX Wires Have Become Grey and Brittle

This is a common issue with the older Lego 9V cables. Lots of sources, including myself, have experienced the same thing - this particular chemistry of insulation ages poorly, no matter how well it's ...
MindS1's user avatar
  • 1,392
9 votes

Minifigure Hand broken and stuck in arm

I've had this problem several times before. There are two general ways to solve this issue. Brute Force Needle Stick several needles into the arm area at an angle. Then simultaneously push down on ...
Rohan D'Souza's user avatar
8 votes
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Non-standard diameter pole - reinforcing a repair

One option might be to make yourself an ABS slurry by dissolving a sacrificial part of the desired color in Acetone: This should be able to bond chemically with the ABS parts for a strong connection, ...
jncraton's user avatar
  • 40.6k
6 votes

Can I repair a broken LEGO brick with glue?

LEGO bricks are made from ABS. Therefore the most effective adhesive would be ABS cement from the hardware store that sells it for plumbing repairs. ABS cement in theory would chemicallyc weld the ...
Ian B's user avatar
  • 61
6 votes

How to disassemble LEGO train engine base part# 28743?

I was able to remove the screws properly with a Torx T9 screwdriver from our Duplo Train Push & Go Motor (28743).
palacsint's user avatar
  • 648
5 votes

Minifigure Hand broken and stuck in arm

The tiny screw method works. We dipped it in dish soap, made a tiny groove with a thumb tack and then threaded a very small screw. Used two pairs of plyers, one on the arm and one on the screw, and ...
Julie's user avatar
  • 51
5 votes

EV3 screen stuck at "Starting..."

It sounds like the firmware needs a factory reset. Try this: Remove the battery for 10 seconds and then put it back Hold the Center and Right buttons until "Updating..." pops up on the display ...
jncraton's user avatar
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5 votes
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EV3 screen stuck at "Starting..."

Try flashing the firmware. To get into firmware update mode, hold down the right button when turning the EV3 on. (You can also reset the EV3 without removing the battery by holding down the back and ...
David Lechner's user avatar
5 votes
Accepted

How to open Duplo train base 2961b?

This part wasn't meant to be taken apart, but it is possible. Source with more text and images also this (very dark) video tutorial and another video tutorial
Syberion's user avatar
  • 12.6k
5 votes

EV3 Home Shuts down after 2 min. (lights orange, and 3 Icons Triangle, Gage, Manual)

There is a full map of the EV3 user interface here. Although the popup in the photo is in the diagram, it is not labeled. So we have to go digging around the EV3 source code to find out what it means. ...
David Lechner's user avatar
5 votes
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How to open first version of the pneumatic cylinder? (Part no 4688c01)

Thanks everyone for the answers. It gave me the courage to take the piece to the cutting block... And guess what? I now have an almost functional piece. It's not extending 100% and sometimes I need to ...
Daniel's user avatar
  • 221
4 votes
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Is it possible to repair LEGO box creases?

Since creases in cardboard are not mere folds but instead constitute real damage to the box, I don't think you can undo a crease to make it look new again. Even "sort of" straightening it out will not ...
Phil B.'s user avatar
  • 16.9k
4 votes

Why are my pieces breaking? "3612 Arm piece straight with 2 and 3 fingers"

During the 90's I was gifted older LEGO bricks from a friend of my parents that were about 30 years old. Many were discolored, warped and specifically the blue and gray pieces would break if flexed. ...
Rin Rio-Oki's user avatar
  • 8,893
4 votes

Lubricating 4.5V 6216m2 engine

You don't need to open the motor to get the lubricant in. Electric motor oil is thin enough to work in if you hold the motor with the shaft uppermost and slowly rotate the shaft by hand while ...
Rory Alsop's user avatar
  • 1,166
4 votes

Minifigure Hand broken and stuck in arm

I extracted two broken hand stumps with a hot needle and replaced them with unbroken hands from less important or otherwise broken figures. Procedure: Position the figure's arm pointing straight out ...
EL_DON's user avatar
  • 445
4 votes

Problem With Bionicle Joint Sockets Cracking, Repair Options?

The socket joints from around 2008-2010 were poorly designed. They were both too thin and too tight, so cracking was a very common problem. Because the issue is the shape of the part, super glue ...
Pubby's user avatar
  • 5,216
4 votes
Accepted

How to locate pneumatic leak

According to various sources, LEGO pneumatics is not designed to work above 3 (or maybe 4) bars of pressure, so your setup might have been damaged by the overpressure. If you can "press on the the ...
zovits's user avatar
  • 16.6k
4 votes

How to open first version of the pneumatic cylinder? (Part no 4688c01)

The original glue was solvent based. This means that both sides of the joint are more or less fused/welded together. It is not a simple case of "2 pieces with glue in between". Any solvent ...
Tonny's user avatar
  • 1,284
4 votes

Lego Mindstorms EV3 broken screen cable

First of all: before doing anything else, contact LEGO customer support. There's nothing to lose by doing so. According to the video at https://www.youtube.com/watch?v=gPNJC5Uz9HY , it's possible to ...
IvanSanchez's user avatar
  • 8,917
4 votes
Accepted

Duplo train engine base part - replacement DC motor - which part to buy?

I don't have that DUPLO part handy, but this certainly looks like a standard type 130 toy motor: These are available at many online electronics parts stores. Before you order, you'll likely want to ...
jncraton's user avatar
  • 40.6k
3 votes

Minifigure Hand broken and stuck in arm

I just got one out using a very small drill bit and twisting it with my fingers. Took about a minute of twisting to make a hole in the hand piece. Then pressed the drill bit to the side of the hole I ...
Kevin's user avatar
  • 31
3 votes
Accepted

How to fix the 4.3V output supply of a NXT 2.0?

Finally I've found a solution. It is not perfect since I wasn't able to find the schematics of the NXT-2.0 nor could I reverse engineer it. But this workaround seems to work pretty well. This ...
Holger's user avatar
  • 141
3 votes
Accepted

How to safely straighten 2569 Lego Antenna Whip 8H?

It's not a particular rare part, easily replaced with bricklink for a couple of cents, so I wouldn't worry about damaging it. If it's bent it's damaged anyway. For standard lego made out of ABS the ...
Michael Verschaeve's user avatar
3 votes

How do I repair loose arm joints?

I have done this many times over the years, and it is a fantastic solution. Separate the parts, and take a very tiny amount of crazy glue and put a dab inside the joint. Let it dry overnight before ...
Roger Hill's user avatar
3 votes
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Repairing disintegrated old 9V wire

MindS1 is correct that in terms of electrical properties you don't need to be terribly picky. As you noted you will want multicore wire to allow for flexibility and prevent breakage. I'd also add ...
jncraton's user avatar
  • 40.6k
3 votes
Accepted

Replace Battery in LEGO Dino Attack Light-Up T-Rex Head?

Unfortunately after attacking this piece from every angle with some plastic opening tools, I'm quite certain there is no non-destructive way to open this piece. I tried slipping a spudger in every ...
Alexander O'Mara's user avatar
3 votes

My LEGO character's helmet keeps falling off... Is there any way to fix?

The best and most effective technique I've come across is to use a bit of nail varnish on the inner anti-stud of the helmet piece, as Tonk explained on his blog TonksToysBlog. Just be sure to apply a ...
Magnus's user avatar
  • 1,453
3 votes

Power Function IR Remote always emitting after putting batteries

The Lego Company is usually very good about replacing broken and defective parts for free. In the case of expensive electronic parts such as this, in my experience, they will sometimes request you ...
JohnnyB's user avatar
  • 3,274

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