Why Could You Fix Old TVs by Hitting Them?

(Last Updated On: January 12, 2023)

You remember or still own one of those clunker box televisions, you probably remember punching the thing really hard whenever it stopped working so it would get back to showing you whatever you were watching. Maybe you had a stick you kept by the TV to use as the repair-bat. Nowadays, if you do that to your technology, you’re probably just going to break a really expensive piece of hardware—so something has changed. Why could you fix old TVs by hitting them?

Further Reading: Why Did Old TVs Get Static?

It’s a Mechanical Issue 

Hitting something so it stops malfunctioning is called percussive maintenance. It also includes shaking something so it gets back to working, but smacking stuff with a stick is more fun. 

Anyway, many electronics can fail because the mechanical parts in them fall out of alignment. If you’ve ever had a TV remote start rattling around when you shook it, you probably understood that immediately to be a what’s called a “bad sign.” Switches, gears, or even loose wires can be knocked back into their proper positions with a good shake or hit. Nowadays many mechanical components, like switches, are flipped electronically rather than mechanically, so the point of failure is less likely to realign something or knock an “off” switch “on.” 

Your Clunky TV

That brings us to the cathode ray tube television. CRTs physically “paint” the display with the image really, really fast. You can imagine it kind of like a printer that prints super fast; each sheet of paper as a frame of the video. Images come from a heated filament inside a glass tube. This tube is also a vacuum (this is why they can explode if punctured). This heated filament transports electrons from one side of the TV to the other in a beam, and the inside of the television screen glows on contact with the beam. 

This beam has to make it to every pixel on your TV, and it’s what “paints” the image onto your display. It moves so quickly you might be able to hear a high-pitched whine from a CRT as it works (if your hearing is sensitive enough). 

Back to the tubes. Inside the cathode ray tubes is that heated filament we talked about. If you’ve ever heard a building creak in the wintertime, you know how temperature can mess with things. When something gets hot or cold, it expands and contracts with changes in temperature. These filaments are no different, and their temperature has to change a lot just by virtue of being turned off or on. They can also be affected by the ambient temperature outside the TV. This expansion and contraction can loosen or knock the tubes/filaments out of alignment, and it’s one of the more common points of failure in a CRT. Smacking or shaking it can help reseat the tubes inside for a better connection. 

What About My Fancy Computer Monitor

Just briefly, the reason why hitting stuff doesn’t work on a more modern monitor is because there aren’t a lot of mechanical pieces in it. OLED and LCD use organic LEDs or liquid crystals to show stuff to you. Both work by sending electricity through the panel and using a glass filter to display color. There aren’t a lot of mechanical parts that can fail in new screens, which is why smacking a more modern TV is probably just going to break the glass inside—and is less likely to fix the thing than a CRT. 

If you almost got your TV working by hitting it, maybe you ended up with these almost-TV shows here.

About the Author:

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Kyler is a content writer at Sporcle living in Seattle, and is currently studying at the University of Washington School of Law. He's been writing for Sporcle since 2019; sometimes the blog is an excellent platform to answer random personal questions he has about the world. Most of his free time is spent drinking black coffee like water.