mcdonald@sfu_dipper.cs.sfu (12/15/87)
I have recently noticed an odd and unlikeable quirk in my Mac II monitor. A short time after being turned on (say 1-2 minutes) its image will shiver up and down very slightly for a few seconds, and then stabilize. So far as I know, this is recent behaviour only--I certainly never noticed it until a few days ago, and have had the Mac II for quite a while. Is this normal, or is it something I should worry about? Will it get worse? The Mac II at the University Sales Centre is displaying similar behaviour, so this may not be an isolated instance. Thanks for the comments. K. McDonald Simon Fraser University Vancouver, B.C.
gillies@uiucdcsp.cs.uiuc.edu (12/20/87)
This "shivering" always happens when you degauss. Try pressing the
degauss switch on the back of your monitor. Have you tried the
degauss switch when this happens?
I can imagine our monitors might have an "autodegauss" circuit that
fires a little while after you turn it on.
I've seen my monitor flicker the same way, but I can't remember if it
was only during startup.
Don Gillies {ihnp4!uiucdcs!gillies} U of Illinois
{gillies@p.cs.uiuc.edu}shap@sfsup.UUCP (J.S.Shapiro) (12/22/87)
In article <76000085@uiucdcsp>, gillies@uiucdcsp.cs.uiuc.edu writes: > > This "shivering" always happens when you degauss. Try pressing the > degauss switch on the back of your monitor. Have you tried the > degauss switch when this happens? > > Don Gillies {ihnp4!uiucdcs!gillies} U of Illinois > {gillies@p.cs.uiuc.edu} Not knowing anything at all about color monitors, it would seem to me that this is the reflection of a poor design. As I understand it, occasional degaussing is going to be necessary because of some of the fields that get built up in the monitor, but these days I am finding that I need to degauss my machine every time I turn it on, which at the least is a pain in the but. Is this indicative of a badly tuned monitor? Jon
martyl@bucket.UUCP (Marty Lee) (12/22/87)
In article <11540094@hpsmtc1.HP.COM>, kwallich@hpsmtc1.HP.COM (Ken Wallich) writes: >I have recently noticed an odd and unlikeable quirk in my Mac II monitor. A >short time after being turned on (say 1-2 minutes) its image will shiver up >and down very slightly for a few seconds, and then stabilize. So far as I The same thing happens to me except it may happen after 1 minute, 1 hour or 1 day of being turned on. Sometimes the "shivering" goes away after a few seconds to a minute but may reappear at some other time. I leave my Mac II on most of the day so I've ruled out a temperature sensitive part. (Happens sometimes just after being turned on and at the end of the day other times.) Anybody have any comments?
danm@tekig5.TEK.COM (Daniel Milliron) (12/23/87)
We have a Mac II with an Apple color monitor and have experienced the same shimmer/vibration described in previous articles. I don't know what causes it, but we have been able to stop it instantly whenever it appears by simply shifting the monitor a few inches and then back again. The monitor sits atop the Mac II box in the typical position. I have not tried hitting the monitor. Theory: If hitting the monitor fixed the shimmer, we'd have heard about it, since hitting is the intuitive thing to do. Therefore, the problem is probably not a loose connection, since hitting would fix it. Instead, perhaps there is a marginally unstable feedback loop causing oscillation when excited by a transient field flux. Moving the monitor could break the excitation and stop the oscillation. Dan Milliron