Introduction: How to Dismantle a CRT Monitor
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About: My favorite hobbies are learning how to do new and cool stuff from more experienced people and building DIY (Do It Yourself) projects. They involve your typical household items that are usually discarded and … More About MrJentis »
Have an old or useless CRT monitor or TV your considering to throw out?
Well, before doing that, you might want to consider salvaging the onboard components such as the transistors, heatsinks, resistors, capacitors and especially the flyback transformer for later cool projects.
The goal here is to keep the tubes out of the landfills because they contain large amounts of lead and phosphor, and stuff you really don't want to pollute the environment which may seep into the underground water supply.
Taking apart a TV or a monitor may sound easy, but it can be very dangerous if you don't practice safety procedures.
You can also see a slightly different tutorial on my website
In this instuctabe, I'll show you how I dismantled two CRT monitors.
Step 1: Materials
Disclaimer:
Taking apart the TV or monitor can be very dangerous. High voltage may remain stored inside the tube even after being unplugged for a few years. Be careful not to drop the CRT. You could get seriously injured or die if mishandled. I am NOT responsible for any injuries you may receive for failing to adhere to proper safety procedures.
Having said that, lets begin.
For this task, all I used were:
- a pair of rubber gloves
- two cutting pliers
- a Phillips screwdriver, and
- a Flathead screwdriver
- a safety goggles
Note:
These are the tools you will need for your typical disassembly, but may vary according to the types of fasteners used. Wearing your safety goggles is important to prevent eye injury or blindness in case of an implosion of the tube.
Step 2: Remove the Screws Holding the Case Together
Remove the screws holding the back on.
You should also also check for plastic tabs usually located on the top in between the seam and at the sides or bottom.
The top tabs were particularly tricky to unhook, but were eventually popped opened.
Sometimes the screws can be truly hidden, and takes a while to find. Some may behind small plastic doors and others may be hidden behind stickers.
Step 3: Slide the Case Off
Once you have removed the all fasteners, you can slide the case off. At this stage, its best to place the tube on its face. It makes the disassembly process much easier.
Since the CRT may still hold a lethal charge, I recommend that you put on your insulated gloves for the next steps and don't touch high voltage components for safety purposes.
Step 4: Discharging the CRT
To do this, you will need to ground the wire that is under the suction cup that is on the side of the tube.
Connect the flat-head screwdriver to a piece of wire whether by wrapping it around the screwdriver or by a alligator clip and connect the other end to ground.
For example, a metal rod sticking from the ground provides a conducting path to the earth.
Gently insert the flat head screwdriver under the suction cup.
Continue inserting it until it touches the metal conductor and you should hear a ZAP! if the tube still contain a charge. At this point the CRT is discharged.
Continue to pry of the connector until it is removed.
Now that the connector is removed, you can proceed to the next step.
Step 5: Cut the Ground Wires From the Tube
In order to separate the circuit board from the tube and the casing, you need to cut off all the ground wires from the around the tube. Here is an example shown above.
You should also remove the springs attached to the wire which may come in handy for later use.
Step 6: Remove the Main Circuit Board
On this monitor, to remove the circuit board, two tabs under the bottom must be first be unlatched before the metal base with the circuit board can be removed.
With the tabs released, the circuit board can now be moved freely.
Unplug any electrical connectors that are connected to the main circuit board.
Once the main circuit board is free to move from the main assembly, the rest of the connectors are revealed.
Unplug the quick connectors and cut the remaining soldered wires close to the circuit board so that the wires are more useful later.
The last set of wires are attached the the smaller circuit board, so cut them off from that end.
Once all the wires are removed, the main circuit board can be removed.
Take special care not to damage the circuit board because you will desolder the onboard components later.
Step 7: Remove the Smaller Circuit Board
The next step is to remove the small circuit board attached to the tube. It is normally held on by a strong adhesive at the base of the CRT connector.
Just take a flat head screwdriver and pry in between the seam of the tube connector and the tube until it comes apart.
The glue was the only thing holding the circuit board fixed to the glass tube's base.
Step 8: Stripping the Neck
Since I intend to strip out everything from the monitor leaving only the tube and the casing, that meant I had to remove the stuff from the tube's neck as well.
You should prevent from breaking the tube because sometimes breaking the tube, means it can't be recycled once your done.
So take care when handling this part of the disassembly.
To begin taking the stuff off, there is usually one or two clamps that must be loosened first. Loosen the clamps and carefully remove the spacers from around the neck. These are all the spacers removed from the neck of the tube and one of the two metal clamps.
Once the spacers and other obstructions are moved out of the way, the steering coils can come off.
To do so, first pry off the four insulated cushions at the base of the coils and then the coils should be free to slip off.
Step 9: Putting the Case Back Together
At this stage, the casing is put back together. The tube was not removed from the casing because it's a lot safer and prevents the neck from accidentally breaking off.
Now you can take the CRT to a recycling facility. Keeping the CRT out of the landfill is the objective here.
As mentioned before, you don't want the toxic substances such as lead to seep into the earth which may contaminate underground water supplies.
If you followed all the steps closely, then you will have a similar compilation of parts shown above.
Please note that I also spared the monitor's swivel base that may be of great use on a later project.
Of coarse, your final compilation will vary depending on make and model and whether it is a TV or computer monitor.
I hope you have found this tutorial useful.
Here are some links to my other instructables:
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47 Comments
4 years ago
These instructions should start in the first few lines with clearly warning people about the dangers of CRT tube implosion, then explosion. There is a proper way to "air a CRT", but you have to know how to do it.
7 years ago
Well I have some lil diff problem...what it is that I got a 17" Crt samsung Syncmaster793s monitor which acts as a display for my old P4 2.8 GHz PC. Now the back board of it somehow got loose so creating color problems...like when you off a single RGB signal line bt if you rake the back circuit board a lil it comes back again....like the joint got somewhat loose...so pins at joint not making full contact.
How to correct it?
I mean I wud have to remove that glued board and reattach it again.....how to do it safely....and wud fevi quick will do the job? I mean putting it back in place :)
8 years ago on Step 9
Do you know if it's in the tube part, or the circuit board that holds the charge when you discharge it? I didn't hear a zap when I did that step but i didn't want to take any chances so I clipped the wire and just left the suction thing on the tube. It's a really old tv and it crumbled when I picked it up so I wanted to shed all the unnecessary parts for when I bring it to be recycled. The tube has been unplugged for over 10 years now so it might not even have a charge anymore.
Reply 7 years ago on Introduction
The charge is in the tube. Newer CRTs I believe have bleeder resistors built in, which slowly discharge it over time.
Also, if you didn't hear a zap, removing the suction cup and cutting it would do the exact same thing.
8 years ago on Step 9
I was disassembling old tv and didn't know how to do few things, but now i know :P Thank you! It was very helpfull :)
9 years ago on Introduction
I have dismantled my old CRT monitor and now I have no idea how to dispose the Tube itself. [kids usualy trow rocks at them, when they find one laying on the road side, just to hear the BOOM!]
9 years ago on Introduction
The charge is between the out side of the CRT and the inside surface and the whole thing is floating above earth ground. If the ground in the monitor or tv is not hooked to the earth ground then it will not discharge all the way. To get full discharge run a third wire from clamp / screwdriver and the chassis ground.
9 years ago on Step 4
recycling monitor
9 years ago on Introduction
Nice Instructable! CRTs are gold mines when it comes to salvaging parts :)
10 years ago on Introduction
Hi,
I have a question for you, as I don't know much about electronics. When removing an older (2000) large Sony Trinitron CRT tv to make room for my son's new flat screen tv in the playroom, the big old tv was dropped, cracking the plastic housing (as far as I can see). The screen is still intact. I was not home at the time of the incident, but the man moving the tv said he did not hear an explosion noise. I had the tv removed as soon as I read how toxic tv materials can be (it was in the playroom for about 6 hours after the drop), but I'm now concerned about potentially hazardous materials in my house. If the screen is not broken, and I saw no traces of broken glass anywhere (only a crack in the plastic near the speaker), can I assume that the CRT is also intact? Should I be concerned about toxic or radioactive materials leaking out with no external evidence?
Reply 10 years ago on Introduction
There should be no cause for concern because the harmful materials are applied as a coating on the inside surface of the CRT. If the glass is not broken, then there should be no leakage. The glass is very thick and is relatively hard to break.
10 years ago on Step 4
Those gloves aren't going to do you much good if you get a zap. :/
Reply 10 years ago on Introduction
Your absolutely right. My pair of rubber gloves were unavailable at the time so I just put on a pair of gloves for the sake of wearing them for the demonstration. I was unlikely to get zapped because:
- I was holding the insulated handles of the jumper cable and the screwdriver
- The wire was grounded, so any electrical energy would take the path of least resistance, i.e, through the wire, and
- my tube had already been discharged mysteriously during operation (see image soot mark on the case that's just above the positive lead to the tube)
Thanks for pointing that out though, I'll make a note to use rubber gloves in my pages.
Reply 10 years ago on Introduction
The "soot" marking on the top of the case is just the electrostatic attraction of dust, and it's perfectly normal. A functioning flyback transformer has a built-in bleeder resistor that drains the charge when the monitor is turned off - but this high voltage resistor can fail, and that's why you always discharge the CRT before touching. Also, IF the CRT is charged, i would recommend mounting a strap from the Anode connection to the rimband which is grounded on the CRT to avoid charge building up again (it can charge up again due to deep charge in the glass)
Reply 10 years ago on Introduction
I was thinking the same thing. Cloth gardening gloves would not be my first choice for Hi-pot work. If you don't have a pair of proper rubber electricians' gloves, then rubber dishwashing gloves (2 pair, one inside the other, by preference) are better than nothing, and certainly mores safe than cloth gloves.
10 years ago on Step 5
I just found a 20 inch color tv down a hill. I tried it . it works. So i will keep it I played "Namco game on it. You could have kept that monitor and tried to build a "COMMODORE COMPUTER" . Well the storage of all those monitors might have lead to an oriental "Mein Kampf " somewhere. I have taken apart over 500 electronic sets. I often resort to kicking the thing apart. After I get a bunch of circuit boards I use a propane torch and a pair of pliers to remove components. I donate working parts to "COMPUTER ZONE OF SANTA CRUZ". I donated a working Koss boombox CD to Abbotts. I know that todays computers dont have the sophistication of FORTRAN computers of the 1960 and 1970's. I took thousands of 74xx gates off of assorted computer boards. Those computers made customized paths for each numerical program written. The circuits had numerous "buses" instead of only 1 data bus and one address bus as is used with a simpler microprocessor computer. Please get busy and build all of us a non microsoft computer like a "Commodore" And make a billion dollars.
10 years ago on Introduction
"Have an old or useless CRT monitor or TV your considering to throw out?"
Going to have to stop you right there, Jentis. The flash bleached out the projector, and you can't see the displays to the left along the countertop with the tower, but you get the idea.
Until I scrape the money together for a graphic card capable of a quad display, or a cheap videowall adapter...a cloned duodecuple display will be equally entertaining.
Reply 10 years ago on Introduction
Heh! Interesting way of re-using CRT monitors. Now, if you could just get a few more, you could have a "wall of video. An entertaining experiment, although I'd hate to see the power bills, LOL.
Reply 10 years ago on Introduction
I've got more, but this is my only projector wall. As it stands, this shrunk my screen from over eight feet to under six. Besides, any more here, and the wiring is going to get scarier than the power bill. That one VGA line has a powered four-way splitter, eight-way splitter, and a scan converter acting as both a splitter and a booster. The room was wired for heavy power draw...but I still don't want to plug power strips in to power strips.
Oh, and it seems the complementing portion of my comment was cut off when I pasted it in. Honest and for-truly, this started as a "Kudos" kind of post, not a "look-what-I-did-that-is-unrelated!" post. I've been asked several times to gut a CRT for people who just want the case. It's nice to have a place of cautionary instructions. Reading the comments, you've also created a nice forum area for other people to voice other cautions.
10 years ago on Introduction
For those of us who are electronically disabled,I think we need more instructables like this to show us how to disassemble things to salvage parts for use in other projects. And that includes all the great feedback .
