Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!ceres.physics.uiowa.edu!news.iastate.edu!vancleef
Newsgroups: comp.sys.ibm.pc.hardware
Subject: Re: Spurious "Disk is Write Protected"
Message-ID: <1991Mar24.211652.27371@news.iastate.edu>
From: vancleef@iastate.edu (Van Cleef Henry H)
Date: Sun, 24 Mar 1991 21:16:52 GMT
Sender: news@news.iastate.edu (USENET News System)
References: <103405@unix.cis.pitt.edu>
Organization: Iowa State University, Ames, IA
Lines: 41

In article <103405@unix.cis.pitt.edu> djbpitt@unix.cis.pitt.edu (David J Birnbaum) writes:
>My 5-1/4" 1.2M floppy drive has been refusing to write to diskettes,
>telling me that the "Disk is Write Protected."  This problem began some
>six months ago and was very rare; it has since become extremely
>frequent.  In the past, jiggling the diskette a bit would cause the
>drive to accept it, but this no longer seems to work.
>
>The drive reads properly and on those rare occasions when it is willing
>to write, the files it writes are readable both by the drive in question
>and by a drive on another machine.
>
>The diskettes are all high quality and formatted normally.  There is no
>visible dust or debris inside the drive in question.
>
>Is this a known problem?  Is it one I can repair by myself and, if so,
>how?  Given the bargain basement prices of disk drives, it hardly seems
>worth getting it repaired professionally, but if all it needs is some
>particular cleaning in some particular place, I'd be grateful if some-
>one could let me know.
>
>=======================================================================
It is very likely dust in the light path for the sensor.  I have had 
this problem a number of times with TEAC 1.2meg floppies on my machines,
usually after a long period of not using the floppy.  Often, just putting
a vacuum cleaner nozzle as close to the light head as you can will clear
the fault.  However, with one floppy, I have had to take it out, remove
the screws holding the top card, and clean out inside.  I could not see
any visible dust, but blowing out the light source and sensor and holes
between solved the problem.  

One thing that is a factor is that in most machines cooling fans suck
air through the floppy slot.  

If your machine has run for a long time, I would also suggest that 
you remove the power supply and vacuum all around it.  I have been astounded
by the dust buildup I have found on machines that ran in relatively clean
areas and that looked clean when I took the cover off---the dust is
underneath where you can't see it.


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