Questions tagged [repair]

Bricks, pieces and other elements sometimes break, deform, stop working, or get otherwise damaged - perhaps we can help you fix them?

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How to fix this Error in EV3 Classroom? [duplicate]

So I got the error "Heads up! Couldn't open this project" and did research and found out that it is a generic error, then looked up the exact error on this site: https://legoapptools....
5 votes
1 answer
281 views

Repairing a 12V switch motor

My son caused me to dig up my old 12V LEGO trains. Surprisingly they mostly work, except for one part - Electric, Train 12V Remote Control Switch Motor 4 x 8 x 1 2/3: This is the motor that drives ...
3 votes
1 answer
65 views

Type of Battery connector of Spike Prime & essential Hub

What is the type of the 3-pin connector used to connect the Spike Prime Hub or Spike Essential Hub to the rechargeable battery? It consists of 3 pins and has a male and a female side. I have issues in ...
3 votes
1 answer
269 views

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

I have two Duplo train base parts, one that works, one that I want to repair, as it does not work (connects via Bluetooth, but in the end motor does not move). I disassembled that and figured out the ...
2 votes
1 answer
521 views

Can I open/repair this Duplo pullback motor?

My son has a Duplo pullback motor. This motor does not work well. After pull back it moves forwards 2 and a half wheel turns and stops. There is a small resistance forcing it forward two millimeters ...
12 votes
9 answers
12k views

How do I repair loose arm joints?

The arms on my LEGO minifigures are loose. How can I repair these to remain in place when I move the arm to the location I want it to stay in?
1 vote
2 answers
906 views

Calibration Freeze on D11

I've read through similar posts, but haven't seen exactly the same issue. Built it once, and froze during several calibration attempts. Stripped it all down, rebuilt it very carefully and still have ...
19 votes
2 answers
12k views

Is it possible to change the battery in a 54604 light brick?

I got 4 of these in in a bulk lot of Lego, but the lamp is getting quite dim in a couple of them. Is it possible to change the battery in a 54604 light brick? It looks like the brick should open, ...
4 votes
1 answer
165 views

Wobble problem with the PF L motor

So I got my hands on a used 42095 LEGO Technic set that I wanted for a long time. After disassembling it and testing PF for the first time, I have noticed that one of the motors is extremely wobbly, ...
1 vote
0 answers
108 views

LEGO Express 60197 displays low battery

Using new batteries to power the controller - however on connecting the app using Bluetooth the status immediately shows low battery. Uninstalled the app and reinstalled it with new set of batteries, ...
1 vote
3 answers
440 views

Lego Mindstorms NXT 2.0 brick is not working

Recently, I tried to get my old NXT 2.0 brick fixed. Everything seemed to point to the clicking brick problem, but it turns out not to be the only thing, the brick was also getting hot. After ...
2 votes
0 answers
117 views

How do you open this thing without damaging it?

It's a 9008 DUPLO Activity Set from 1986. Looks like this on all the boxes.
3 votes
1 answer
554 views

Lego Mindstorms EV3 broken screen cable

While taking apart my EV3 brick I accidently pulled on the ribbon cable connecting the screen to the motherboard too hard and it broke. I figured I could just get a replacement fpc ribbon cable with ...
3 votes
1 answer
594 views

Correct axle rotation of partially built LEGO Cat D11 Bulldozer (42131)?

Page 173, Step 205, of LEGO Cat D11 Bulldozer (42131) instructions has a step to attach two sub-assemblies. What is the correct rotation of these two axles? Is it correct if they rotate in opposite ...
6 votes
1 answer
340 views

How can I prevent rubber bands disintegrating?

These two answers partially answer this question., but I think it's worth its own question to find more options in a more comprehensive answer. Old Lego rubber bands are known to become brittle over ...
2 votes
2 answers
3k views

Fixing a not working Power Functions L motor

Four of my PF L motors don't work. How could I make them work again? I didn't find any information about L motors, only M and XL.
3 votes
1 answer
323 views

How do I switch out a gear in the Cat D11 set without taking the set apart?

I have a fully completed Cat D11. Great build. (I have previously built the Bucket Wheel Excavator, the Rough Terrain Crane, Liebherr 9800, Airbus 175, etc.) Couldn't get through calibration. Did not ...
2 votes
0 answers
174 views

Fixing a LEGO M Motor connector

I have several broken "Powered Up" M motors and I took one apart to see what was wrong. I ended up snipping off a section of the wire and re-soldering it back together but testing with an ...
5 votes
0 answers
158 views

IR remote 8879 - cannot control speed of the motor

I got the 7938 train set for my kid. I hook up the battery to the receiver and try the IR remote 8879 with it. The motor starts running/spinning, but I can not control the speed with the orange "...
7 votes
1 answer
623 views

Fix Power Functions cable near connector (L motor)

We have a broken cable on the power functions L motor. I've fixed an M-motor before in the engine, but this time the cut is near the connector. Unlike the M-motor, this connector doesn't have the ...
7 votes
0 answers
195 views

Oil for old 4.5V motor? (UK)

I've just got my old LEGO Technic motor from my loft. It works but squeals in a way I don't remember it doing (35 years ago). I assume some lubrication would help and I've seen references to 3-IN-ONE ...
3 votes
1 answer
320 views

Small torso cracking

I have a ton of LEGO Minifigures I am putting up for sale on my Bricklink, but I just noticed almost every single figure looks as if there is a crack right under the arm starting at the armhole and ...
7 votes
3 answers
385 views

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

I have a Lego Technic set 8040 from 1984 with the first version of the pneumatic cylinder. Unfortunately, the shaft on the cylinder broke. Apparently the top of the cylinder (lid) is glued. Is there a ...
2 votes
1 answer
253 views

Where can I get replacement battery connectors for old Lego Duplo Train?

I have the same Duplo Train that Pieterjan posted a picture and video of in September ('Old Lego duplo train not working on batteries'). In my case, it is clear that the battery connectors are ...
0 votes
0 answers
90 views

How do I disassemble Powered Up Motor XL? [duplicate]

My question is, how do you take the XL motor apart? I tried with my knife and hands, but unfortunately, it is still whole in one piece (tabs). I got the XL motor from the set 42099 and I would to make ...
5 votes
1 answer
137 views

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

I just purchased a second hand LEGO Mindstorms Home EV3. The brick turns on, allows firmware update, etc. However, after about 2 minutes the unit makes a noise, LED's turn red, and 3 icons appear. ...
13 votes
1 answer
2k views

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

I have an ancient 74569 motor: Unfortunately, it's broken: The shaft spins freely by hand, but when I connect power to it, it doesn't spin at all. I would like to see if I can just open it and place ...
2 votes
0 answers
192 views

NXT Sensors/Motors not working

I went back to using the NXT brick after two years and I'm having some problems: Motors do not respond to degrees or rotations; Ultrasonic Sensor and Color Sensor are not working; Touch Sensor is ok; ...
8 votes
1 answer
2k views

How to restore minifig faces?

Vintage minifig heads (from the 80s, 90s with the classic smiley) often lose their eyes and mouths after years of play. The paint wears off. How do you best restore the heads?
3 votes
3 answers
3k views

How can I fix my chewed up LEGO head?

When I was about 8 I used to bite down on loose LEGO heads to "fix" them. Of course after the heads "treatment" they would have chew marks around the neck. Is there any way to make these marks less ...
14 votes
6 answers
8k views

Minifigure Hand broken and stuck in arm

A friend of mine gave me some of his old minifigures. As you guys can see, the hand of one of the figures is broken and a part of the hand is stuck in the arm. Do you have any ideas how to remove the ...
6 votes
0 answers
282 views

Fix Lego M Motor - The hooks aren't budging

I have a Lego M motor that is broken. I'm following the instructions here to try to fix it but the little tabs that hold the plastic frame together just won't budge no matter how hard I'm pushing them ...
6 votes
2 answers
4k views

Repairing disintegrated old 9V wire

I have a number of old technic motors and battery boxes I would like to use however the wires have disintegrated in storage to the point that the metal conductors touch and short out. Does anybody ...
5 votes
0 answers
201 views

what plastic is used in the floatable hull of 60266 Ocean Exploration ship?

I need to know what plastic is used for the hull (dark blue) of the 60266: Ocean Exploration Ship, in order to glue a reinforcement on. I bought this for my boys (younger than the advertised 7+). It ...
16 votes
3 answers
8k views

How to disassemble LEGO train engine base part# 28743?

I have one of the new Bluetooth engines (part 28743, but in the bottom it says Hub No 5 model) that has started to under-perform and make some noises, I think that it need some maintenance (maybe due ...
32 votes
2 answers
18k views

How do you repair yellowed or faded LEGO blocks?

In particular, I've had white blocks that have yellowed in places. Can the colour consistency be restored? Or at least improved? I'd be more interested in people's actual experiences rather than ...
8 votes
3 answers
2k views

Is it possible to shrink down a wheel?

I have a tire 6581 which is stretched to the point it doesn't fit perfectly with the balloon designated for it, at one place it is kinda popped out. It is caused by my stretching it when I was younger ...
7 votes
1 answer
186 views

Reinforcing a pair of Bent Double 11.5 Liftarms under Rotational Tension

I purchased a clone MOC out of interest a few months back, this following set. Because it does use clone pieces, I knew there was a high chance of breakage and poor fit, especially in the tensegrity ...
14 votes
2 answers
784 views

Is it possible to dismantle and refurbish an original 870 Technic motor?

I have a couple of ancient 870 motors (the 4.5v ones) that run but don't sound great. I've looked for, but can't find, a guide on how to dismantle them. I'd like to either get in there and clean/...
12 votes
1 answer
2k views

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

Is it possible to replace the battery of the LEGO Dino Attack T-Rex head? There's a button on the top of the head that makes the eyes and tongue light up red, presumably via a red LED. There doesn't ...
11 votes
1 answer
280 views

12V LEGO train tracks splinter

I have an older 12V LEGO train (several actually) but of course the rubber tires wore out long ago. The trains still run quite well (I even used them as a motor parts in some Technic designs), but the ...
5 votes
1 answer
223 views

Broken pneumatic distribution block

I have a first-generation Lego Pneumatic set (nr 8851) that I recently took out of storage. I remembered from the last time I built the set that the pneumatics weren't working and I just confirmed ...
3 votes
1 answer
138 views

What is the maximum voltage for motors from Cybermaster units?

I recently bought a non-functioning Cybermaster unit [part:71797]. As the motors in there might be perfectly fine, I'd like to use them. I could not find information on these motors (as opposed to ...
10 votes
3 answers
2k views

Old RCX Wires Have Become Grey and Brittle

I have a LEGO MINDSTORMS Robotics Invention System 2.0 (3804) that I acquired back in 2003 (17 years ago), and the wires have become grey and brittle. The wires used to be black and smooth, and ...
3 votes
1 answer
208 views

Miniature Lepin box door stuck inside box itself

Yes, maybe the title may be confusing, but this image says it all: I got a Lepin city set not too long ago, and it included this box. I have no idea how this happened but during use the door ...
5 votes
0 answers
121 views

How do I fix a loose joint between the top and bottom of the digger base?

How do I repair a loose-fitting joint between the top and bottom of the Duplo digger base? It has been used for only about a year. Is the wear more likely on the top or the bottom piece?
6 votes
2 answers
841 views

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

I have a Mindstorm NXT 2.0 from 2007 (PCB code: 62115.40H) at which the sensors except the simple "Touch sensor" are no longer working. Also the tacho-signal of the motors do no longer work. (The ...
4 votes
4 answers
3k views

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

My figure won't keep its helmet on and if I get it on it is very loose and will spin around.
2 votes
1 answer
2k views

Unable to turn on NXT. Completely Frozen [closed]

I recently downloaded a file on my NXT and when I used it, it didn't work as intended. The motors started to make sounds like they were jammed, one got stuck and now the NXT won't even turn on. I ...
2 votes
0 answers
152 views

How to repair warped plates [closed]

I have some large plates and a boat hull that have warped due to temperature, and I would like to fix them. Is there any way to do so? And if not, is there any way to replace them? I tried contacting ...