home *** CD-ROM | disk | FTP | other *** search
- Newsgroups: comp.sys.mac.hardware
- Path: sparky!uunet!usc!cs.utexas.edu!qt.cs.utexas.edu!yale.edu!news.yale.edu!YaleVM.YCC.Yale.Edu!LILMARA
- From: LILMARA@YaleVM.YCC.Yale.Edu (Martin Lilly)
- Subject: Magnetized monitor NOT = Junk or How to Degauss
- Message-ID: <16B4F14B9A.LILMARA@YaleVM.YCC.Yale.Edu>
- Sender: news@news.yale.edu (USENET News System)
- Nntp-Posting-Host: yalevm.ycc.yale.edu
- Organization: Yale University
- Date: Thu, 07 Jan 93 23:34:50 EST
- Lines: 84
-
- Thanks to everyone who replied to my plea for help regarding the
- magnetized monitor. For those of you who didn't see the post, my
- six year old daughter was doing "experiments" with a magnet she
- got for Christmas. The "result" was an expensive color monitor with
- ugly green blotches all over.
-
- I was assured by everyone that it was a minor problem that could
- be resolved by removing the spurious magnetic fields by a process
- called degaussing.
-
- My first step was an attempt to identify an internal degaussing
- button inside the monitor. I couldn't find one in mine, a Seiko
- CM1445.
-
- On the suggestion of Arthur Dunham, I attempted to scramble the
- magnetic fields using the same magnet my daughter had used.
- First, I removed the monitor far from the cpu (and my thesis),
- plugged it in and turned the brightness to max in order to see the
- distortions. I brought the magnet in close to the screen and slowly
- withdrew it while rotating it simultaneously. This creates some
- interesting special effects similiar to some After Dark modules,
- though I don't recommend magnets as an alternative. By
- withdrawing the magnet at the correct angle, I was able to
- alleviate 95% of the problem.
-
- Although this was much better I wasn't quite satisfied, so I dug out
- a very powerful speaker magnet I had in the basement. This
- magnet is difficult to pry off of any object it's stuck to. Amazingly, I
- could create monitor distortions from about 6 feet away. With this
- magnet, I followed a protocol Rick McCormack sent me, which I
- include here:
-
- __________________________________________________________
- Rick McCormack's de-gaussing procedure:
-
- You have already received much advice about correcting the
- problem. If you decide to do it yourself (i.e. if you have a tape de-
- magnetizer, once common to bulk erase 7-inch reels of recording
- tape), it is easy to do and even easier to mess up. Proper
- precautions include; take off your watch!
-
- Don't do it with-in the area where your stereo and audio cassettes
- andfloppies and hard drive are--move the monitor to where you
- have a large clear area around it (see why in the next few steps).
-
- Turn on the selected de-gausser (bulk eraser, coil, etc.) when it is at
- least six feet away from the monitor. Approach the monitor from
- head on, moving the de-gausser continuously in circular motionsof
- about 8-12 inches, covering an area that extends about 16 inches
- outside the monitors perimeter (top, bottom, both sides) and covers
- past the centre of the monitor (you want to describe arcs that go, for
- example, from about 16 inches above the top of the monitor to
- about 2 widths of the way down the monitor surface, then swings
- out to about 16 inches past the monitors side, back across 2 of the
- monitors width then down to the bottom, etc.) Vary the distance
- from the monitors screen--start the coil about 6 feet away, bring it
- in, moving it slowly but continuously to about 2-3 inches from the
- screen for several passes as described above; then begin backing off
- from the screen whilerepeating theabove passes. The object is to
- "confuse" the comprehensive magnetic pattern that your daughter
- set up, and make it progressively weaker and more disturbed.
- Finally, don't turn the de-gausser off till it is at least six feet from
- the screen again. And watch out for what is called 'duty cycle". My
- bulk eraser has a 25% duty cycle, meaning it can be on for a
- maximum of one minute continuously, then must be left off for at
- least 3 minutes before being used again. This prevents it from over-
- heating and blowing out.
-
- I hope this hasn't discouraged you from attempting this simple job-
- -I just wouldn't want you to do it wrong and give up. Lotsa luck
- and let us know what you did and how it worked.
-
- UseNet: Rick_McCormack@mindlink.bc.ca | A O-L: Rique
- ________________________________________________________
-
- This worked beautifully, and I have a distortion-free monitor.
- Had it not worked I could have just taken it to a dealer
- or TV repair shop for a professional degauss job.
-
- Thanks again to everyone for vindicating my daughter. We
- degaussed the screen together, and I'm letting her eat food again
- (Just Kidding!!)
-
- Martin Lilly LILMARA@YaleVM.YCC.Yale.edu
-