The monitor that I use at work seems to have electrical current running through it. Whenever I touch the screen I get this fairly strong buzzing electrical feeling through the tips of my fingers. I asked the tech guy and he blew it off as “static” electricity, but I’ve felt static electricity before; it goes “snap, crackle, pop” and then disappears. This is a long term “buzz” akin to the feeling one gets when they get shocked by an electrical socket.
I know that glass doesn’t conduct electricity (1.5 years of college physics taught me that), so the “static” thing might be true.
Any idea what’s really going on?
Thanks!
PS: the monitor is behaving normally otherwise ie no image distortion or thick black smoke comin’ out the back.
PPS: Any links to this phenomenon would be apprecciated.
I have experienced the same thing, usually on TVs (yes, I sit too close, ok?). I think that it is just poor insulation, resulting in a charge bleeding out. Don’t know why though.
CRTs can have a very high static charge on the surface - why do you think it gets dirty so fast? That charge attracts any poor dust particle that might float near it. Normally, since you aren’t touching the tube and a piece of grounded metal, you don’t feel anything, but if you were to grab onto a pipe or something and touch the tube, Whoa Nellie!
I used to work in the Camera/electronics department of a local chain. I was wiping off the dust on the TV screens one day. We had a metal support post about 3" in dia. about 10" in front of the TV display wall. While I was wiping a TV screen down (that was on) I happened to lean back against this pole at the same time. Wow! That is something I’m never going to do again!
Maybe you’re resting on something metal (have your feet on a metal chair, your desk is metal, etc) and are completing the circuit when you touch the screen
It’s a fan. Probably one in the computer tower. The vibration is getting transmitted through the desk. You’ll probably feel it if you rest your hand lightly on the desk, too. That’s why it feels like a “buzzing” sensation.
Oh and glass does conduct some electricity. That’s how those lightning ball displays work. When you touch them a very small current flows through the glass and you to ground. You can see it if you hold your finger a tiny distance from the globe without actually touching it.
I went to Sam W’s Repair FAQ but nothing like this seems to be listed. It is very important to determine if it is static electricity or AC current (or worse!). If it’s the later turn it off, unplug it, do not use it. If it’s “only” static electricity, then that’s just Not A Good Thing. No way should a normally operating CRT produce enough juice to produce buzzing in a person. Since the OPs description sounds like AC current or a very strong static situation, continued use of the equipment could be quite hazardous.
Every piece of electronic equipment that has given me a buzzy type shock from touching the outside of it was faulty or mis-wired in some way.
Its not the fan. The box itself is sitting on the floor on typical office carpet and not touching the desk. Besides this is an “electrical” buzz, not a vibratory one. After having installed more than my share of light swithces without taking out the fuses in the fuse box I’ve learned to discern the difference.
As for CRT’s having a high static charge, I’ll buy that. But then why doesn’t my one at home (or anyones else’s at the office) exhibit the same behavior? This not normal.
I guess I should let it go. I hafta admit 90% of the reason that I asked was based on his attitude. He acted like I had no idea how computers work because HE was the tech guy and I was just an “end user”.
Well, I do have a college degree (Biology), I’m a programer (Microsoft and Sun certified), and the machine that I’m using right now is one that I built myself .
With the TV turned off, stick a piece of aluminium foil over the entire screen. Turn TV on. Touch aluminum foil.
Okay, don’t actually do this. If you do, you’re a :wally
Nothing any more dangerous than running your hand over the whole screen. You’d get a nice shock from touching a grounded object, if the screen is a TV, but it wouldn’t kill you.
I fail to see how this could be anything other than static buldup on the screen, since the OP seems sure it isn’t a mechanical vibration, and even that seems highly unlikely. Unless the monitor has an extreme cathode overvoltage, there’s not enough static on the screen to feel. Hell, maybe it’s psychosomatic.
What would we expect to happen if JamesCarroll found a nice ground, like the 3rd hole in a wall outlet; got some insulated tongs and some nice 14-guage copper wire (that’s almost 1/8" thick wire); and plugged one end into the ground and touched the other end to the PC?
–first making sure there are no witnesses, and preparing a statement to the effect: Hey something’s happened to my computer! (just in case)
At the least he would find out if the electrical condition is hazardous or not.
Could be a loose or broken ground strap inside the monitor, or the monitor might be plugged into an outlet with a floating ground or with reversed polarity (hot neutral).
I have two monitors side by side of different brands and models. One does this and the other one doesn’t. One has such a strong static charge that you can hold a sheet of paper and it will stick to the screen like it was held by a vacuum.
It was explained to me that the CRT will do this because of the electrical charge inside and early CRTs were just left like that. Those grounded screens they sell to place in front of the screen are precisely for the purpose of canceling this electric field.
The newer monitor does not do that becuse the outside of the CRT already has built in a conductive layer for this purpose.
