How to take a thing apart without breaking it too much
Sometimes, when you want to repair something, it almost falls apart, and sometimes it is impossible to open it without destroying it. If that happens repair is often out of the question. And once you have it all apart, it can be quite tricky to reassemble everything because you forgot how everything fits together (especially if you had to wait several weeks for a replacement part).
Some tricks for taking things apart
Let’s start with the first and simplest trick to learn how to open many things. Search for it! You can use your favorite search engine to search for “Device XY disassembly” or “Device XY teardown” to find articles or videos on how to take something apart. Often a dedicated search on youtube can be worthwhile as well. By observing someone else opening your device you can see where they had problems and try to not make the same mistakes. Possibly, they include how they repaired the damage they have done with their method.
This approach has saved me several ours of searching for hidden screws or finding out where to “break” open a plastic case.
If it is not obvious on how to open something up and you do not find something on the internet, you have to fiddle out yourself how to do it. This leads us to the second trick to know about disassembly. Take pictures! Before every step of disassembly, I tend to snap one or two pictures of the screw, cable or cover I intend to remove. Often it is not obvious how things come back together once you have dozens of parts laying in front of you. I recently opened up a Yamaha receiver which had four different (but similar) types of screw in the cover of the housing alone.
Next you are well advised to group things together that belong together. I usually take a small zip-loc bag for screws and small parts and tape them to the device they belong to. When it comes the time to close everything up, you can compare your parts for this step with the pictures you took and put everything back in the right place.
I would like to talk a little bit about the different methods that can be used to close a housing. I could (and maybe will) write a whole story about each one of them but the following should give you a starting point.
Screws
Screws are probably known to everyone and in principle easy to open. In many situations it is just a question to find all the screws. After having loosened all the screws you have found and you can’t easily open the case, chances are there, that you missed a screw. Often you can pull on the different parts of the case and feel where it moves and where it doesn’t. This is a clear indication, that there has to be as screw nearby. If you can’t find anything, maybe you have hidden screws, or another form of fasteners (see below).
Some companies think it is a good idea to use some form of special or security screw. Maybe you have already encountered some weird screws. If you don’t know a screw head, have a look at the List_of_screw_drives on wikipedia. I recommend to buy a decent set with different security and speciality bits such as this Proxxon Set or this iFixit Pro Tech Set for smaller screws. You can buy cheaper sets, but chances are extremely high that you damage the bit or the screw or both with a cheap set.
Hidden screws
Sometimes screws are very well hidden. Be it for esthetical reasons or be it for “protection” reasons by the manufacturer. Whatever the motivation, you have to find the screw to get inside. A popular place to hide screws is behind the rubber feet of the device. You can either pull them off if they are glued or pull them out if they are pushed into the housing. Most of the time you can easily put the feet back when you are done with your repair.
Another place to hide screws is under stickers or labels. This is often done as a form of tamper evidence. You can feel with your fingers whether there is a hole under a sticker and then push through it with your screwdriver.
A last place where you can look for screw is in battery compartments or under some other lids that can be removed.
Rotating objects
Maybe you need to take something apart that rotates. I recently had to open a kitchen aid mixer and wanted to replace a thermo fuse on the motor. The motor was attached to the coupling on which you can put your blender. The coupling used a left-handed thread so that it tightened itself during normal use. I had to grip the coupling and the motor with some good pliers and turn the right (this means the other way than usual) way to take it apart. This video showed me how to do it after several other methods failed.
Whenever something turns, try to turn it the other way than it usually turns and it could open on you.
Snap-fit plastic cases
Snap-fit cases use small hooks to hold two parts together. They can be used alone or in combination with screws. Two open them up first remove any screws you can find. The you need to carefully pry the parts apart with some kind of tool. I do not recommend using your nails, chances of breaking them are just too high. A screwdriver can work but will probably leave ugly marks on the case. Different mostly plastic parts like credit cards, guitar picks or something similar can open the seam without damage. You could also use a butter knife. There is a specialized tool called a spudger which does the same.
These types of joints require some resolve during opening them. Often it feels as if you break something when the small hooks get loose. Always make sure that there are no screws before applying the necessary force.
Glued enclosures
One of the more annoying techniques to close a housing is to glue it shut. It is cheap to produce, hard to open and often hard to close back up. Many cell phones are glued nowadays but fortunately you can probably instructions for most models.
Technique-wise you can use similar techniques as for the snap-fit housings but with finer spudgers. Another technique is (as with many other problems) hitting it with something hard like a screwdriver or a rubber hammer. The shock can open it along the seams. A last one is to put it in a vice and to apply pressure from the corners. Put a rag around it if you do not want to scratch it too much.
A thing that often works as well with glue is to apply some form of heat. Either use a hot air gun or a heating plate (if you happen to have such a thing).
When finished you can glue it back together. If you intend to open the device another time, better close it with some duct tape. Be aware that glue is sometimes used to make a device water-tight. Chances are high that you lose this feature when closing it back up.
Welded enclosures
To round it all up, I want to lose some words on welded enclosures. They are similar to glued devices but even more annoying. The image at the start of the story shows a typical welded enclosure. Most of them are closed with a process called ultrasonic welding. These can be really hard to open and, in many cases even harder to close. The chances of breaking a welded enclosure are quite high. This is especially the case if the plastic is from an older device.
You can try all the techniques described above for glued housings. But chances are high that you can’t get a spudger in, heat does nothing and it won’t move at all.
Before breaking the case completely by squeezing to death it in your vice. You could try to cut the housing open with a saw or rotary tool. Then you have some chances to glue it back together. Be careful though, often welded enclosures are used to protect the user from mains voltage which, admittedly, is dangerous. If you can’t seal it properly afterwards it could be VERY dangerous for future users.
conclusion
As you see in the main image, not every attempt at opening something goes well. Especially in highly integrated products the opening process can be quite a challenge. The best way is to see if somebody else has already done it. Use the techniques described above. If it is not clear what technique has been used to close a housing, just carefully try out your options. A last resort you could use is to destroy the case and build or 3d-print a new one.
