🚀 go-pugleaf

I'm wondering if anyone has ever run into this problem before, and if so, 
has anyone ever found a solution:  In the last three weeks, three PC's -- 
a pair of 486SX machines and a 286 -- have come into our repair shop with 
an identical problem.  The 3.5"/1.44 meg drive will not read high-density 
disks.  It reads 720K disks without a problem.  It reads 1.44M disks, but 
only when they are write-protected.  If not, the drive will crap out 
("GENERAL FAILURE READING DRIVE A:", etc.), and the FAT and BOOT sectors 
of the disk are destroyed (interestingly, ViruSafe reports that the disks 
are infected with Michelangelo, although they are most certainly not).

What seems to be happening is that every time the drive attempts to access 
a 1.44M disk, it first performs a write operation somewhere in FAT and 
BOOT area, rendering the disk unreadable.  When the disk is 
write-protected, the write operation fails and things carry on as usual, 
except that a floppy isn't much good if you can't write to it.

I am convinced this is a motherboard problem.  I've switched out the 
drive, the cable, the controller, the hard drive, the CPU, and the 
RAM.  The power supply connections all tested OK.  Nothing works, and 
what's more, *ALL* of these parts work fine in another motherboard 
(including the drive).  I've even tried replacing the oscillator on one 
of the boards: nada.  Anyone got any suggestions?

Thanks,
-- John
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|John Howard Eli Fiskio-Lasseter  |     "Is obair-la\ to\iseachadh"   |
|e-mail: johnl@yang.earlham.edu   |    ("Beginning is a day's work")  |
|        JOHNL@EARLHAM.BITNET     |                --Gaidhlig Proverb |
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