Introduction: How to SAFELY Salvage Cathode Ray Tube Televisions
There is no doubt about it: CRT televisions are inferior to modern monitors. They contain unstable components, are hazardous to the environment, have attrocious picture quality, and make a dreadful noise when plugged in. If you have a CRT television you have probably thought about throwing it out and replacing it at least once, but if you are an electronics hobbyist you can also take it apart easily. These televisions yield tons of parts and the can be found at the goodwill for around five dollars. However, recklessness (as usual) is not recomended. The cathode ray tube (the wonky-looking device in the uppermost photograph of the instructable) is sensitive and will implode if care is not taken. This salvage mission can turn into a recipe for disaster if you do not read through the safety CAREFULLY!
Step 1: Stuff You Need
The following is a list of required tools and equipment:
-Screwdrivers (philips and flathead)
-Gloves (I used heay-duty cleaning gloves)
-The television itself
-Wire cutters/strong scissors
-desoldering bulb/soldering braid
Step 2: Safety/Things You Shouldn't Do
This is a list of things you SHOULD NOT DO:
-Crack the screen
-Remove the springs keeping the tube in place
-carry the CRT by the neck
-touch any components with your bare hand before discaharging the circuit.
Please keep in mind that I am by no means responsible for the safety of other individuals. Any injury, death, or damage to property due to accident, ignorance, stupidity, recklessness, failure to read this warning, or any combination thereof is the fault of the person who caused the incident in the first place.
Also keep in mind: one of the most dangerous things of all is stupidity (hence my photograph).
Step 3: Open the Casing
To get to the guts of the television, unscrew the screws which hold the device together and jiggle the outside to pull off the back of the television. Do not pull it off with too much force to ensure the neck of the tube stays intact. If your television contains tamper-proof screws, you may not be able to take your television apart without more specialized tools.
Step 4: Cut the Wires
Before you do this, put on the pair of gloves because the capacitors on the board and the CRT itself can store a charge for months. Next, get your wire clippers/sharp scissors and cut any wires going to the CRT. Note: DO NOT CUT THE SPRING GOING ACROSS THE SIDE OF THE CRT! Cut every wire, including the one going to the suction cup. Many people push a flathead screwdriver under the suction cup and pry it out instead, but I cannot say I have tried this myself. After the wires going to the CRT, electron gun board, and coils of wire around the neck have been cut, you are ready for the next step.
Step 5: Extract the Circuit Boards
This step is simple enough: pull the main board out of the television. In some cases the board will be mounted without screws. If you have a television like this, just pull out the board. If it is screwed onto the case, pull out the screws and extract the circuit board afterwards. REMEMBER TO WEAR GLOVES, ESPECIALLY IN THIS STEP! Next, detach the small board on the top of the electron gun. You will notice in my photographs that the board that came on the neck of my tube is still on. This is because mine wouldn't come off, and if yours is like this do not force it off. Instead, just leave it to avoid fracturing the tube. This board will typically snap on and off of the tube via a connector.
Step 6: Discharge the Components
When you extract your board the capacitors will still hold enough electricity to give you a nasty jolt. With your gloves on, use a flathead screwdriver to short out the pins of all of the components, especially the large electrolytic capacitors. To short out the components, initiate contact between the pins with the head of the screwdriver. Repeat for the smaller electron gun board. Make sure you discharge everything before taking your gloves off and proceeding to the next step.
Step 7: Desolder the Components
Now that you have gone the trouble of taking the television apart, it is now time to extract the useful components. To do this you need a soldering iron, as well as a desoldering bulb/braid. The first thing to worry about should be the flyback transformer. You can just torch it if you have a blowtorch, but if you don't it will take some effort. I had to do it without a torch and it worked fine (after around thirty minutes of sucking up solder and pulling). Next you can just desolder the rest of the components normally. It is perhaps best to use a pair of needle-nose pliers to extract the components to avoid burning of the hands. The television should yield plenty of resistors, transistors, transformers, capacitors, and diodes to last you a long time. Afterwards you can dispose of the board. To dispose of the CRT, go to a waste maneagement facility. DO NOT JUST CHUCK IT INTO THE DUMPSTER!
Step 8: Make Use of Your New Parts!
Most passive components salvaged from the board can be used for future projects. Meanwhile, you can use that big flyback transformer to produce 20-30 KV if hooked up correctly to a flyback driver. There are many potential driver designs out there, and while I have not yet gotten any to work, it is certainly worth a try!
That's it for this instructable. I hope everyone got something out of it. From now on I will be posting guides like this one, all of which are intended for those who seek a new DIY project.
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