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20 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. ...
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  • 8,718
16 votes
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What element is this a piece of, and how can I repair it?

It's difficult to tell exactly what part this fragment came from, but it looks like it is part of a broken Technic gear or pulley. It looks like it probably came from 3736: Your fragment looks like ...
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  • 34.5k
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. ...
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  • 5,090
12 votes

Can I safely dissassemble a 74569 motor (the old, fast 9v one)

Well, I opened it up without much success, and took some pictures of the process: At first I tried pushing/prying the light grey tabs away from the dark gray "bottom", but those weren't budging So ...
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  • 1,146
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 ...
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  • 1,330
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 ...
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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, ...
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  • 34.5k
7 votes

How can I fix my chewed up LEGO head?

Your best bet would still be BrickLink. Many sellers there accept cash, checks or money orders, so you don't necessarily need paypal or a credit card. However if you would like to work on fixing the ...
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6 votes

How to restore old, scratched plates

Brasso (yes, the metal polish) works better than toothpaste in this case. It is a bit more grainy so works faster but doesn't damage the parts. It does take some work though that may or may not make ...
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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).
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  • 646
5 votes
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How to restore minifig faces?

If you have a steady hand you can use hobby paint or a Sharpie, let it dry, then put on a clear-coat for protection. But those heads with the classic smiley faces are so cheap on BrickLink, you could ...
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5 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 ...
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  • 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 ...
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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 ...
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5 votes
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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
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  • 11.1k
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 ...
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  • 51
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. ...
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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 ...
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  • 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 ...
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  • 16.5k
4 votes

Can I repair a broken LEGO brick with glue?

It's sometimes possible to build a jig out of other Lego blocks to hold the broken pieces firmly together to allow the glue to set and the result to be very good. I use my worst-condition bricks for ...
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  • 141
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 ...
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  • 1,168
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 ...
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  • 445
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. ...
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  • 8,718
4 votes
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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 ...
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  • 13.9k
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 ...
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  • 1,170
3 votes

How do I repair loose arm joints?

Put a little clear nail polish or paint on the part that connects into the torso. Not too much, though, or the torso will crack
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3 votes

Cracked LEGO torso

These cracks will often get worse over time as the legs are removed and replaced, or simply from normal play. Even if they don't get worse, the legs probably already have low clutch power which may be ...
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  • 34.5k
3 votes
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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 ...
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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 ...
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  • 31
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 ...
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  • 34.5k

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