My Fixing Escapade: Troubleshooting a Fan and TV

[Inquiring_Mike]

My 'fixing' escapade...

Hey,
When I recently came home to my parents house, I found a fan and an old t.v. that "do not work". I have taken apart the fan, with nothing to show for it. Its one of those stand-up fans... The "switchboard" where the fan settings are looks to be fine, the connections seem to be clean.. The extension cord looks good as well. The "guide" (determines how far the fan goes either way) seems to be fine as well... It doesn't have any electrical parts so that shouldn't be the problem anyway.. The only thing left is the part where the vacuum or whatever is created... Any ideas??

My question about the t.v. is if I can open it up? I heard that t.v.'s can be dangerous, probably due to the capacitors and such.. But this t.v. has been sitting around in the attic for more than a year now...

Thanks for any info!

 

[berkeman]

Hi Mike, It's good that you're curious and want to start taking things apart to see how they work, and maybe even fix a few broken things along the way. But you definitely need to be careful as you start working with electrical things. If you know somebody who is experienced with electrical and electronic things, it's best to ask them for help and tips as you get started. For example, with a DVM (digital voltmeter), you would be able to diagnose the broken fan fairly quickly, and determine if it would be easy or hard to fix.

The TV is especially dangerous for two reasons. First, TVs use a non-grounded power cord, so there is no ground reference inside in the metal chassis and circuitry areas. Most TVs use Neutral as the "chassis ground", and Neutral can have plenty of AC voltage on it with respect to external ground references. So you can shock yourself badly (and even die), and you can blow up expensive test equipment if you try to work on an open, powered TV without using an Isolation Transformer. Even if you don't power it up, the high voltage that is under the rubber button on the CRT (where the flyback transformer high voltage wire goes into the picture tube) can stay there for a long time. I don't think there will be any high voltage left there after years of storage, but certainly days or weeks after being turned off, there can still be part of that 23kV left inside the tube. As long as you don't plug the TV in, it should be relatively safe to take apart and look around.

What grade are you in? It sounds like you would enjoy some engineering-type classes, if they are available to you. -MikeB-

 

[Averagesupernova]

One of the most important things not yet mentioned with the TV is the tube itself. It is under a very high vacuum and if broken will implode sending glass flying everywhere. I shot at an old disgarded TV once with a .22 revolver to see what would happen. Yes I was at a safe distance and yes it imploded, not just shattered, you could hear the whooooomp.