*BSD News Article 90698


Return to BSD News archive

Path: euryale.cc.adfa.oz.au!newshost.carno.net.au!harbinger.cc.monash.edu.au!nntp.coast.net!howland.erols.net!cam-news-hub1.bbnplanet.com!cpk-news-hub1.bbnplanet.com!news.bbnplanet.com!mindspring!uunet!in3.uu.net!198.69.204.8!news.fast.net!news.pgh.net!usenet
From: Jim Durham <durham@w2xo.pgh.pa.us>
Newsgroups: comp.unix.bsd.freebsd.misc
Subject: Re: wavy video under X ?
Date: Sun, 09 Mar 1997 22:11:15 -0500
Organization: Dis-
Lines: 51
Message-ID: <33237BD3.2781E494@w2xo.pgh.pa.us>
References: <5fi3dh$7hc@saluki-news.it.siu.edu> <01bc28db$f6374f20$3b8dc7cd@bw.aa.net>
NNTP-Posting-Host: w2xo.pgh.pa.us
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
X-Mailer: Mozilla 3.01Gold (X11; I; FreeBSD 2.1.7-RELEASE i386)
To: brian wehrle <brianw@aa.net>
Xref: euryale.cc.adfa.oz.au comp.unix.bsd.freebsd.misc:36816

brian wehrle wrote:
> 
> I recommend reading the /usr/X11r6/lib/X11/docs/README.(your vidoe chipset)
> file.
> They usually have tips for changing /etc/XF86Config file that would apply
> to your
> video card/chipset.  Just a little tuning is probably required.  I' m not
> sure if that path is correct.
> 
> 
> Jim Dutton <jimd@dutton4.it.siu.edu> wrote in article
> <5fi3dh$7hc@saluki-news.it.siu.edu>...
> > I have been running X11R6.1 (XFree86) for some time now, and lately, the
> > screen has begun to wave (on a Gateway-2000, Vivtron 1572 monitor). I
> used
> > Xvidtune to see if changing mode sizes would help, and while it did slow
> the
> > wave down in a couple of the modes, it hasn't emlimnted the wave
> altogether.
> >
> > There isn't any magnetic source near the monitor.
> >
> > How bad of an indicator is this wave, and what else should be done about
> it?
> >

My guess is that it is a hardware problem. If the software worked at
first,
then it should work now.

The most likely thing is hum in the monitor's power supply. This has
a frequency of 60hz. If your monitor's vertical scan rate is, say, 65hz,
you will get 5 "waves" per second (the difference of the 60hz hum
frequency and the vertical scan frequency.

A tip-off to this is that you can have slight horizontal "stripes"
rolling
through the picture also, moving usually from bottom to top.

My advice...if you have electronic skills, check the power supply in
your
monitor. If not, try another monitor. If it works OK, send yours in for
repair.

I doubt it's XFree86. Changing the scan rates in the X config
(by the way, it's /usr/X11/lib/X11/XF86Config ), may change the
frequency of the "wave", but probably won't eliminate it.

Good luck

Jim Durham