Anth's Computer Cave

TV Teardown

I have often wondered whether there are useful parts to salvage from old TVs, particularly now when it seems you can't drive down a street without seeing at least one on the curb. After tearing down this Samsung I now know there are good parts to salvage, but I am still unsure if it is a viable activity when you consider the waste you are left with.

The unit in question is a Samsung flat-screen CRT TV that was probably one of the last CRTs manufactured before LCDs took over. It was dumped down the road in front of a shop and a couple of friends kindly picked it up, brought it to me and did the heavy lifting while we tore it down. I have acute arthritis so there is no way I could have handled it myself. These things are heavy.

After removing five screws the rear cover came away easily and we could see nearly everything contained in the unit, but this is where you need to be careful.

Safety Warning

The first consideration with CRT TVs and monitors is safety. They are capable of storing power long after they are unplugged.

To avoid electric shock, hook one end of a jumper cable to to the ground cable. This will usually be a bare steel braided cable looped around the tube.

Next, clamped a screwdriver to the other end of the cable then probe underneath the anode cap. This will be a rubber cap on the rear of the screen.

If there is any residual power you will hear a spark. In this case there was no sparks, leading me to believe the unit may have been unplugged for some time.

On to the Teardown

Here is the view with the cover removed. I'm afraid the images for this teardown are a bit blurry and it is too late to retake them.

The first thing I noticed was a bunch of big capacitors and shiny heat-sinks. There was also a large chunk of gleaming copper hanging from the rear of the tube.

You can get a better idea now the components are on the bench.

The board pictured above has some big resistors and capacitors, as well as various MOSFETs and transistors with big heat-sinks.

This seems like the logic board. It has more good heat-sinks and tons of small to medium-sized capacitors. There are also lots of transistor-like pieces I have yet to identify.

Above is the CRT neck board from the back of the TV tube. It has more heat-sinks, resistors, MOSFETs and some good diodes.

The deflection yoke has a fair amount of copper, although not as much as I was expecting.

You would need quite a few TVs to make any real cash from the copper.

The speaker boxes were interesting. They are self-contained enclosures with a woofer and a tweeter.

I have hooked one of the enclosures up to the Cave stereo and they produce reasonable sound.

There was also what appears to be some kind of noise sensor built in directly in front of the tweeter. I assume it provides feedback to the audio processor to enable advanced filtering and sound functions. I don't know much about modern hi-fi equipment, maybe it is something routinely built into systems now. I hope to have a play with it soon.

The image above shows the collection of electrical components I salvaged from this TV. They were attached to the circuit boards with large mounds of solder, so they were easy to remove. There is at least this much again remaining on the boards, but this is all I will remove.

I know there are MOSFETS, relays, switching diodes, transistors, etc, but there are some parts I have not identified yet. I am sure they are really handy for someone who knows what they are and how to use them.

There are large resistors up to 7 watt, and some beefy capacitors and a collection of various-sized heat-sinks.

Lastly, we have the TV case. I originally planned to return the picture tube to the case and send the whole lot to the transfer station for recycling. I have decided the case is too useful to part with. With a coat of paint and some potting mix this will become a nice-looking planter box, and that is true recycling.

Leftovers

Strangely enough, the only waste left over from this teardown is the picture tube. Though it is only one component, it is an important consideration. These tubes are made from toxic leaded glass that cannot go to landfill. I am looking into the best way I can dispose of it safely and legally.

Where I live in Geelong they sometimes accept TVs for free recycling at the transfer station, but I'm not sure if they will accept the CRT tubes on their own. I suspect the companies that recycle these need to make money somewhere along the line, so they would be factoring the valuable things like copper, etc, into their business model to compensate for the cost of recycling the tubes.

I have put the tube safely away for now while I research the options. I'll update this article when I have more details

Summary

So, is it viable to salvage parts from old CRT TVs?

I have not really reached a conclusion yet, but I have a couple of thoughts on the matter.

If you already have old TVs at home waiting for disposal, it is definitely worth grabbing a few things from them, but I don't think it is viable to actively collect them just for salvage.

Also, choose a unit that has a nice looking case. If you can reuse the case for a legitimate purpose it will make the process more worthwhile.

Till next time...

Cheers

Anth

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