Path: utzoo!attcan!uunet!husc6!ukma!mailrus!iuvax!silver!commgrp From: commgrp@silver.bacs.indiana.edu Newsgroups: sci.electronics Subject: Re: Tandon disk drives lose upper head Message-ID: <7200012@silver> Date: 28 Sep 88 19:46:00 GMT References: <718@pedsga.UUCP> Organization: Indiana University CSCI, Bloomington Lines: 34 Nf-ID: #R:pedsga.UUCP:-71800:silver:7200012:000:1439 Nf-From: silver.bacs.indiana.edu!commgrp Sep 28 14:46:00 1988 >I have had two Tandon TM-848-02 floppy drives fail recently. (half >height DSDD 8") Both failed the same way. They worked as double sided, >then the upper head failed. Now they cannot read nor write the upper >side, but function okay as single sided. >The heads look fine. What went wrong? Can I fix it easily and >cheaply? (Remember that new drives are $50 at computer fairs). > >Jeffrey Jonas Upper head failure is common on all floppy drives. Unlike the lower head, the upper head is mounted on a delicate suspension. Sometimes they fail for no apparent reason; the most common failure mode is the upper head being torn away because someone put a disk with a warped jacket into the drive, or because a technogeek interpreted the message "Put a write-protect tab _ON_ the disk" literally. :^( It's not economical to replace the heads; new heads cost almost as much as a whole new drive, and a good bit of labor is involved in realigning a new head, even if you have all the right equipment (test set, analog alignment disk, oscilloscope). I have been able to salvage a few drives with bad upper heads: Carefully inspect the solder joints where the cable connects to the flat flexible printed-circuit leading to the actual head. The wires often break here, and the break may not be obvious until you disturb the wire. Broken wires can be resoldered, using a very small tip. -- Frank reid@gold.bacs.indiana.edu