harrison@sunny.DAB.GE.COM (Gregory Harrison) (10/18/89)
My IBM PS/2 Color Monitor just ~sparked! I heard what sounded like an electric spark, and the screen blanked for a second. The PC didn't crash, but it sure was alarming! Is this a common problem? Do I need to call maintenance? Did I get zapped by X-rays? Do yo think that it has something to do with the high static field at the front of the tube? Hope it's not going on the fritz. Greg Harrison My opinions ar not intended to express those of GE
kens@hplsla.HP.COM (Ken Snyder) (10/20/89)
Greg,
I wouldn't sweat it. It was probably just a software bug that flew
too close to the high voltage circuitry and got zapped! I wouldn't worry
too much about X-rays unless the film in the nearest camera is fogged. :<{)
Kenweekley@oldcolo.UUCP (Bob Weekley) (10/23/89)
- >In article <1954@cunixc.cc.columbia.edu> stone@cunixb.cc.columbia.edu (Glenn >Stone) writes: >>Advice on this monitor problem would be appreciated. The text undulates >>back & forth. It only sways a few mm, but it's visually disturbing. I >>tried swapping the monitor (IBM enhanced color display) and also >>swapping the EGA card; it still does it. It's actually quite nauseating >>to watch. Excuse me, I think I'm going to be sick. >> >>GD Stone Seems like it's time to get out the aluminum foil (foiled again!) Wrap the foil around the monitor, and ground the foil with an alligator clip wire to the chassis of the machine. Are you running your computer with the hood on? (the cover is a shield) Is the computer itself well grounded? Make sure all grounds go to a SINGLE POINT. This avoids GROUND LOOPS. Let us know what you found, and how you fixed it. ---------------------- Robert R. Weekley @ oldcolo.UUCP THE OLD COLORADO CITY ELECTRONIC COTTAGE | Standard | 2502 W. Colorado Ave. #203; C.S., CO 80904 |Disclaimer| (719) 632-3391 [8-N-1]; 632-4848 [voice] "Twenty years of schooling, and they put you on the day shift" -B. Dylan ----------------------------------------------------------------------------- -
kens@hplsla.HP.COM (Ken Snyder) (10/26/89)
> Seems like it's time to get out the aluminum foil (foiled again!) > Wrap the foil around the monitor, and ground the foil with an > alligator clip wire to the chassis of the machine. Since the problem is almost assuredly magnetic, foil won't help in the least. Where is the nearest disc drive? Is your monitor sitting on your computer? That is the most likely cause of the problem, the magnetic field from the disc drive motor. It used to drive me nuts too. Ken
eb2e+@andrew.cmu.edu (Eric James Bales) (10/26/89)
> Excerpts from netnews.comp.sys.ibm.pc: 25-Oct-89 Re: SCARY Monitor > problem Ken Snyder@hplsla.HP.COM (473) > > Seems like it's time to get out the aluminum foil (foiled again!) > > Wrap the foil around the monitor, and ground the foil with an > > alligator clip wire to the chassis of the machine. > Since the problem is almost assuredly magnetic, foil won't help in the > least. Where is the nearest disc drive? Is your monitor sitting on your > computer? That is the most likely cause of the problem, the magnetic > field from the disc drive motor. It used to drive me nuts too. > Ken I also have this problem with my new monitor that was replaced only a couple of weeks ago. The new monitor sits in exactly the same position as the old monitor, and is the same model and was made only two months prior to my old monitor. My old monitor did not have this problem. The new one does. Why would the hard drive cause a problem with only one of two identical monitors? -Eric Kirkbride-
lampi@pnet02.gryphon.com (Michael Lampi) (11/02/89)
Wavy monitors tend to be caused by changing magnetic fields near the screen.
For example, if I have my electric clock on the shelf above my CRT, then the
image wavers all over the place. If I move the clock up a foot, then the
problem goes away.
Now, if only I could get rid of this crick in my neck from straining to see
the clock.....
Michael Lampi
MDL Corporation
UUCP: {ames!elroy, <routing site>}!gryphon!pnet02!lampi
INET: lampi@pnet02.gryphon.comjeh@simpact.com (11/03/89)
In article <21739@gryphon.COM>, lampi@pnet02.gryphon.com (Michael Lampi) writes: > Wavy monitors tend to be caused by changing magnetic fields near the screen... Yup. I recently bought a nice new VGA-plus monitor, checked it and the new VGA-plus card out at the store, and brought it home. Worked fine. Then it started to waver... and then it stopped... repeat, ad nauseum (literally). Drove me nuts until I happened to make a phone call from an old-style WE 2500 desk phone (which has many coils in a network in the base), which happened to be newly perched on a shelf near the monitor... and heard AC hum. It turns out that the master power cables for the building (a four-unit townhouse) come straight down through that particular wall, right behind the monitor (judging by the hum)! The hum in the phone and the waver in the screen came and went with varying AC loads in the building. Moving the phone away from the wall stopped the hum, and moving the monitor away from the wall stopped the waver. I traced a similar problem, also in a VGA-plus system, to ground loops. There was a difference of a few tenths of a volt between the chassis ground potentials of the monitor and the computer (the latter as seen at the end of the monitor video cable). This of course caused an current flow in the shield braid of the monitor cable, and may also have imposed a 60 Hz signal atop all of the video and sync signals, exactly what they don't need. Plugging the monitor into the "monitor power" receptacle on the computer (instead of the wall socket) helped some. I then got into the video cable and disconnected the shield from the connector shell at the monitor end, and the waver disappeared completely. I'm sure looking forward to the day when we can get rid of that last vacuum tube! --- Jamie Hanrahan, Simpact Associates, San Diego CA Internet: jeh@simpact.com, or if that fails, jeh@crash.cts.com Uucp: ...{crash,scubed,decwrl}!simpact!jeh