Fortune has favoured the foolish. - Page 1
Forum section: electronics / general

author: Ampera
author_rank: Super Contributor
timestamp: December 25, 2016, 09:47:45 am
content: Not really a question or anything, just through it would be interesting if I posted about what the hell I just did.I have an old iMac G3 Summer 2000 DV+ model that I want to install OSX on. It has worked flawlessly for a long time, but all of a sudden the slot loading DVD drive refused to inject or eject discs (Making it pretty impossible to install OSX, eh?). I hate these things and find no real reason for them to exist, but whatever.Now if you have never seen this iMac it's got a built in CRT, which was when I looked up how long it takes a CRT cap to discharge.Yea, well I took it apart like an idiot.The good news is nothing happened and the drive is fixed, but damn that was stupid. I don't even know what the hell I did, I thought I probably broke it more than I fixed anything. The belt fell off and I put it back on a few times, and I pushed a few parts around, but apparently that fixed that, somehow.Now you might think, unless you have worked on one, that there would be a practically sealed off compartment separating the computer and the display, but no, there isn't. There is a wall, but by no means a seal. Because of the CRT, I decided to "Service" the machine on my bed, soft spot, whatever. So while I was poking around in there (More carefully than I have with literally any other piece of machinery) the rear of the CRT neck was pointed directly at my chest.Either way, it's not borked anymore and OSX 10.3 (All I got) is booting (Off a 4x CDRW that I need to burn my backup images onto, grumble grumble.) and I am not dead (The level of thanks for that one is a question to be answered later in life)but anyways,the airport card was cute tho.

author: KhronX
author_rank: Frequent Contributor
timestamp: December 25, 2016, 10:34:13 am
content: I seem to recall a proverb from back home, something along the lines of "God takes care of children, drunks and idiots"

author: timb
author_rank: Super Contributor
timestamp: December 25, 2016, 11:15:52 am
content: Quote from: KhronX on December 25, 2016, 10:34:13 amYes.When I was about 10 I had an old TRS-80 Model III that I picked up at a thrift store for $10. This was the machine with an integrated CRT. There were slots in the top of the casing and at some point a floppy disk fell inside, so off came the cover! At that point I didn't know about capacitors (or CRTs) retaining their charge; that's a lesson I learned later that year when I took apart a Polaroid camera and the flash capacitor bit me, causing me to fall backwards off the top of my bunk bed (where I inexplicably decided to dismantle the camera) onto the solid concrete floor below!Anyway, I got the case off, retrieved the floppy, poked around a bit trying to figure out how it all worked, then prepared to reassemble it. Unfortunately, in doing so the plastic case caught the neck of the tube, breaking it... This caused a loud hissing sound, which I assumed was the vacuum in the tube filling with air. Now, I wasn't sure exactly how much air the tube could hold, but I was reasonably sure it *was* /at least/ all the air in the house.So, thinking quickly, I filled my lungs with as much air as I could and then started trying to open as many windows as I could before passing out. I didn't pass out, but I did manage to get three windows open! I was so proud I'd saved my entire family from dying like some astronaut with a faulty spacesuit.It wasn't until later I found out exactly how much air a CRT really can hold; turns out it's the same volume as the CRT itself... Who knew!CRTs: It's not the voltage that kills you, it's the vacuum!The more you know! ~~~*

author: Ampera
author_rank: Super Contributor
timestamp: December 25, 2016, 01:21:38 pm
content: Quote from: timb on December 25, 2016, 11:15:52 amThat would be an interesting fate. Death by CRT operated decompression.

author: The Soulman
author_rank: Super Contributor
timestamp: December 25, 2016, 03:23:15 pm
content: Quote from: timb on December 25, 2016, 11:15:52 amI'm sorry that's to funny!When I was 6 I soldered a resistor to a leg of a LED, all was fine but my 4,5 volt battery ran out and I decided to stick the led in a 220 volt mains socket...I was fine but the LED hadn't survivedI know most forum members here are not into religion, but sometimes the existence of guardian angels appears to be proven.

author: Ampera
author_rank: Super Contributor
timestamp: December 25, 2016, 06:40:18 pm
content: Quote from: The Soulman on December 25, 2016, 03:23:15 pmYou just need to be stupid enough, that's all that matters.

author: TerraHertz
author_rank: Super Contributor
timestamp: December 25, 2016, 11:43:29 pm
content: Quote from: TwoOfFive on December 25, 2016, 09:47:45 amWhere did you pick up this fear of CRT's?They really aren't so bad. I spent much of my childhood and teens playing around with CRT TVs from the local tip. There were valve and semiconductor circuitry ones, both were fun to hack around/fix/salvage parts from. Multiple times I hacked out the EHT section from valve TVs, as standalone EHT supplies, and played with arcs and corona discharge 'toys'. CRTs were also interesting to de-vacuum (either gently via the nipple or puncturing the EHT metal clip, or spectacularly via the method best described as 'bricking it'.) I had quite the collection of CRT electron guns, because they are pretty.The only necessary precautions with CRTs are: discharge the Anode fully (grounded wire and screwdriver under the EHT cap), and don't break the sidewalls without implosion containment. Oh, and don't get the screen phosphor, cathode coating or barium getter material in cuts, on food or breathed as dust. Not hard to avoid.