djbpitt@unix.cis.pitt.edu (David J Birnbaum) (03/15/91)
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. Thanks, David ======================================================================= Professor David J. Birnbaum djbpitt@vms.cis.pitt.edu [Internet] The Royal York Apartments, #802 djbpitt@pittvms.bitnet [Bitnet] 3955 Bigelow Boulevard voice: 1-412-687-4653 Pittsburgh, PA 15123 USA fax: 1-412-624-9714
rajah@ohstpy.mps.ohio-state.edu (03/16/91)
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 ...... > > 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. > > Thanks, > > David > > ======================================================================= > Professor David J. Birnbaum djbpitt@vms.cis.pitt.edu [Internet] > The Royal York Apartments, #802 djbpitt@pittvms.bitnet [Bitnet] > 3955 Bigelow Boulevard voice: 1-412-687-4653 > Pittsburgh, PA 15123 USA fax: 1-412-624-9714 we experience the same problem with a computer in our lab. Drive "A" simply refuse to write. But it can copy from drive "A" into "C" or into memory. So no problem with the media (disk). I guess the drive somehow feels there is a protection tab on the disk. Probably the tab sensor does not move freely. We are going to check it soon. Any other suggestion on this is appreciated. Thanks, Rajah.
thoger@solan.unit.no (Terje Th|gersen) (03/17/91)
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. [deletions] Thanks, David ======================================================================= Professor David J. Birnbaum djbpitt@vms.cis.pitt.edu [Internet] The Royal York Apartments, #802 djbpitt@pittvms.bitnet [Bitnet] 3955 Bigelow Boulevard voice: 1-412-687-4653 Pittsburgh, PA 15123 USA fax: 1-412-624-9714 Hi! The drive has a little diode over on the left side, that reads the write-protect notch on your floppy. It sounds like this hole has become clogged by dust. Remove your floppydrive, and check this out. The diode is held in place by a single screw. (There are two diodes on the left side of the drive, you want the one closest to the edge, of course. The wrong one is about an inch from the center hole.) Regards, -Terje -- ____________________________________________________________________________ thoger@solan.unit.no | Institute of Physical Chemistry THOGER AT NORUNIT.BITNET | Div. of Computer Assisted Instrumental Analysis | Norwegian Institute of Technology
rajah@ohstpy.mps.ohio-state.edu (03/18/91)
In article <9675.27e10c98@ohstpy.mps.ohio-state.edu>, rajah@ohstpy.mps.ohio-state.edu writes: > 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 ...... >> >> 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. >> >> Thanks, >> >> David >> >> ======================================================================= >> Professor David J. Birnbaum djbpitt@vms.cis.pitt.edu [Internet] >> The Royal York Apartments, #802 djbpitt@pittvms.bitnet [Bitnet] >> 3955 Bigelow Boulevard voice: 1-412-687-4653 >> Pittsburgh, PA 15123 USA fax: 1-412-624-9714 > > we experience the same problem with a computer in our lab. Drive "A" > simply refuse to write. But it can copy from drive "A" into "C" or > into memory. So no problem with the media (disk). I guess the drive > somehow feels there is a protection tab on the disk. Probably the tab > sensor does not move freely. We are going to check it soon. Any other > suggestion on this is appreciated. Thanks, > > Rajah. > As soon as I opened up the drive realized the sensing of tab is done by optical means----source:an LED, detector: a photodiode. This information is also mentioned by Mr. Quimby and Mr. Terje. Thanks. On testing (experimenting) found the followings: 1. Cleaning dust didn't help. 2. Unpluged the photodiode(detector) as it was easy to remove and did the diode test. Test passed.So photodiode ok. 3. LED wasn't easy to check as it is soldered to the PCB. However, found a short cut. Issued the fomat command without the photodiode in place....hoping to see light from LED. No light from LED. So bad LED. 4. Proof: Shine light on the photodiode with a flash light while issuing format command. It started formating. As shining light on photodiode is disrupted formating stoped with an error message. Now I need to replace the LED. Could anyone help me with the specification and the place where I could buy this LED. Thanks very much. Regards.
vancleef@iastate.edu (Van Cleef Henry H) (03/25/91)
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. --