machf Posted June 17, 2008 Share Posted June 17, 2008 Well, as the title implies, today after a couple of years without using it, I found out that the Mitsumi mech of one of my XF551 drives isn't working properly. If I try to boot from it, I get the usual "BOOT ERROR" messages; if I try to read a disk's directory on it (using it as D2:, which was how I originally had it - changed it to D1: only to test it alone), I get ERROR- 163 (meaning the drive isn't responding). Any suggestions on where to look? On first sight, I can't see anything suspicious, I'm leaving the multitester testing for tomorrow since it's late already. I've already discarded any electronics problems in the board, swapped the mechs with the other XF551 and found out it's the mech. The motors seem to be OK (drive spins normally and head moves normally too), I also cleaned the head and tried to realign it just in case, no changes. Haven't checked solder points in the mech yet (as I said, it's late already - I'm tired and the artificial lighting isn't good enough either), if anybody knows what the "usual suspects" tend to be, I'd appreciate the help. As I said, I connected my equipment after a 2 year hiatus (more or less), last time it was working fine except for one of the SIO connectors (which I already resoldered today) so overheating and such isn't the issue here... Thanks in advance. Quote Link to comment Share on other sites More sharing options...
Rybags Posted June 17, 2008 Share Posted June 17, 2008 (edited) Do those drives do a half-disk seek in/out like most of the others? Try powering it on with the top off to see if the stepper's working OK. Error 163 = Fatal disk I/O errror, don't think I've had one before. There's a thread around where we discuss half-track stepping on the 1050. There's a couple of programs I put in there that can issue diag commands - not sure if they'll also work on the XF-551 but might be worth a try. ed - here it is http://www.atariage.com/forums/index.php?s...pping&st=25 There's some stuff I've put in there in Hidden, Hidden2.zip etc. Edited June 17, 2008 by Rybags Quote Link to comment Share on other sites More sharing options...
machf Posted June 17, 2008 Author Share Posted June 17, 2008 (edited) I guess this was the thread you meant: http://www.atariage.com/forums/index.php?s...pping&st=25 I'll take a better look tomorrow... EDIT: heh, I see you also found it... Edited June 17, 2008 by machf Quote Link to comment Share on other sites More sharing options...
Rybags Posted June 17, 2008 Share Posted June 17, 2008 If you can't fix it or work it out (and you probably know this), ijor and Metalguy are probably the top 2 drive experts around these parts. Quote Link to comment Share on other sites More sharing options...
puppetmark Posted June 17, 2008 Share Posted June 17, 2008 The drive Mech is a standard 360K IBM Drive. You will just have to set the drive select to 0. IF you look around computer shops and e-bay you can probably find a replacement fairly cheap. Quote Link to comment Share on other sites More sharing options...
machf Posted June 17, 2008 Author Share Posted June 17, 2008 (edited) Unfortunately, I'm broke, so I'd rather try to repair it myself. Do those drives do a half-disk seek in/out like most of the others? Nope. Just a short "hop" when powering up. Try powering it on with the top off to see if the stepper's working OK. I've kept it with the top off, seems OK. Error 163 = Fatal disk I/O errror, don't think I've had one before. There's a thread around where we discuss half-track stepping on the 1050. There's a couple of programs I put in there that can issue diag commands - not sure if they'll also work on the XF-551 but might be worth a try. No, they don't... the XF551 uses standard Percom block commands. Edited June 17, 2008 by machf Quote Link to comment Share on other sites More sharing options...
MEtalGuy66 Posted June 17, 2008 Share Posted June 17, 2008 These may seem like stupid questions: But is the shiny metal shield still in place above the upper head? Are the heads clean? Do all the pins in the data connector on the back of the drive (where the cable plugs in) look good? There is also a test point on MOST of those drive mechs where you can hook a scope and look at the actual analog signal coming from the heads when reading. Most of the time, its just a series of solder pads on the board, but some of the older ones had an actual set of pins (like a jumper).. Does that drive have physical wires going to the heads, or one of those chinkadelic "film ribbons"? Is there an optical "track zero" sensor on that model? If you cycle power to the drive when the steper is in a "non-zeroed" position, does it "home itself" and return to track 0 ? If the spindle is spinning at normal speed, the stepper is working, it can find "track 0" (or what it THINKS is track 0, anywayze.) and youve got a waveform comming in from both heads, then its probably an allignment problem. There are alot of really good head allignment utilities for the PC. You have to search for them.. Most are from the MSDOS days.. I cant remember the name of the one I use.. I have to dig it up.. Its probably stored on old Floppies.. hahaha. Quote Link to comment Share on other sites More sharing options...
machf Posted June 17, 2008 Author Share Posted June 17, 2008 These may seem like stupid questions: But is the shiny metal shield still in place above the upper head? That's actually where my worries started. It came off, and I tried fixing it back on place with three points of glue on what's left of the original foam pads (this high humidity has taken its toll on them, apparently). Currently, I took it out to see if it made any difference... why do I have a feeling this may be the likely culprit? Are the heads clean? Yep, I cleaned them. Do all the pins in the data connector on the back of the drive (where the cable plugs in) look good? I've seen far worse, though maybe the top ones need a bit of cleaning. There is also a test point on MOST of those drive mechs where you can hook a scope and look at the actual analog signal coming from the heads when reading. Most of the time, its just a series of solder pads on the board, but some of the older ones had an actual set of pins (like a jumper).. The four ones in a row labeled "TR0"? Unfortunately, I never had the money to buy a scope... Does that drive have physical wires going to the heads, or one of those chinkadelic "film ribbons"? Ribbons. Everywhere (well, mostly). Is there an optical "track zero" sensor on that model? Uh huh. It's labeled [iK] N9V0 on the small PCB on which it's mounted. If you cycle power to the drive when the steper is in a "non-zeroed" position, does it "home itself" and return to track 0 ? Yes, it does. If the spindle is spinning at normal speed, That's something I'm not so sure about... I'll remove the cover from the working one and see if it spins at the same speed. the stepper is working, it can find "track 0" (or what it THINKS is track 0, anywayze.) and youve got a waveform comming in from both heads, then its probably an allignment problem. There are alot of really good head allignment utilities for the PC. You have to search for them.. Most are from the MSDOS days.. I cant remember the name of the one I use.. I have to dig it up.. Its probably stored on old Floppies.. hahaha. I'll try to find some... thanks for your help. Quote Link to comment Share on other sites More sharing options...
Rybags Posted June 17, 2008 Share Posted June 17, 2008 If it was an alignment problem, I'd say 99.9% certain that it should return Error 144, not 163. Quote Link to comment Share on other sites More sharing options...
machf Posted June 17, 2008 Author Share Posted June 17, 2008 (edited) FYI, ERROR 163 is the same one I get when attempting to read a DD disk with the drive stuck in SD... or when I try to read the contents of an unformatted diskette... it's not an uncommon error with the XF551. The drive is reading the first sectors without problems, it's when it tries to read the VTOC and/or directory (sectors 360-368, halfway across the disk) that it fails. I might try a SpartaDOS disk instead and see what happens... UPDATE: with SpartaDOS, I get ERROR 139. With DOS XE, ERROR 144. UPDATE2: tried formatting a blank disk with MyDOS 4.5, kept getting ERROR 144 messages, tried SS/SD, SS/ED, SS/DD and DS/DD, all the same. Edited June 17, 2008 by machf Quote Link to comment Share on other sites More sharing options...
MEtalGuy66 Posted June 17, 2008 Share Posted June 17, 2008 FYI, ERROR 163 is the same one I get when attempting to read a DD disk with the drive stuck in SD... it's not an uncommon error with the XF551. The drive is reading the first sectors without problems, it's when it tries to read the VTOC and/or directory (sectors 360-368, halfway across the disk) that it fails. I might try a SpartaDOS disk instead and see what happens... UPDATE: with SpartaDOS, I get ERROR 139. With DOS XE, ERROR 144. Well, if its readingthe first sectors "no problem" then you didnt fuck up the head when youreattatched the shield.. Ive done tons of those, and never fucked up a head. Its kind of a caveman proof procedure. But what may be happening is an intermittant "open" in the "film ribbon" that goes to the head. Once the steper moves a certain amount and the ribbon gets flexed to a certain position, the tension, or lack of tension onthe ribboncould be allowing a hairline crack in one of the conductive traces in the ribbon to "open".. The other possibility is allignment.. Ive seen drives that were in good enough allignment to read tracks near zero, but the further you get away from it, evetually, the cumulative "offset" from the track on the disk gets bad enough to cause a problem. Have you tried formatting a disk on this drive, writing data, and reading it back? Quote Link to comment Share on other sites More sharing options...
Rybags Posted June 17, 2008 Share Posted June 17, 2008 (edited) OK. I had the impression from the OP that it was refusing to read anything. Do you have a sector copier or something similar? You might be able to use it to determine what track it starts failing on. Edited June 17, 2008 by Rybags Quote Link to comment Share on other sites More sharing options...
machf Posted June 17, 2008 Author Share Posted June 17, 2008 (edited) Looks like I spoke too soon... found my sector copiers, from what I can tell, sector 001 is partially read, but then it stops with an ERROR 144 code. I say "partially" because some data is being displayed... I'm trying to locate a program I wrote long ago to examine sectors of a disk. EDIT: found my program. Looks like it's reading garbage only... Edited June 17, 2008 by machf Quote Link to comment Share on other sites More sharing options...
MEtalGuy66 Posted June 17, 2008 Share Posted June 17, 2008 (edited) Looks like I spoke too soon... found my sector copiers, from what I can tell, sector 001 is partially read, but then it stops with an ERROR 144 code. I say "partially" because some data is being displayed... I'm trying to locate a program I wrote long ago to examine sectors of a disk. EDIT: found my program. Looks like it's reading garbage only... Ok.. When you glued the shield back on, did you get any glue, or sharp pointed instruments down inside the back of the head enclosure? Thats a pretty sensitive area.. But, then again, on normal atari single sided floppies, it's the lower head that it uses.. Could just be allignment too... Edited June 17, 2008 by MEtalGuy66 Quote Link to comment Share on other sites More sharing options...
machf Posted June 17, 2008 Author Share Posted June 17, 2008 No, I was careful. And yes, it's the lower head which should read the first sectors... Sending Percom block commands to the disk seems to work OK, though, so the problem must lie with the heads themselves... Quote Link to comment Share on other sites More sharing options...
MEtalGuy66 Posted June 17, 2008 Share Posted June 17, 2008 No, I was careful. And yes, it's the lower head which should read the first sectors...Sending Percom block commands to the disk seems to work OK, though, so the problem must lie with the heads themselves... I bet its just out of allignment.. Quote Link to comment Share on other sites More sharing options...
machf Posted June 17, 2008 Author Share Posted June 17, 2008 Possibly, but how did it become misaligned by sitting there on my desk for two years? Quote Link to comment Share on other sites More sharing options...
MEtalGuy66 Posted June 17, 2008 Share Posted June 17, 2008 Possibly, but how did it become misaligned by sitting there on my desk for two years? They dont, typically... How much use has this drive-mech actually seen, since it was new? Quote Link to comment Share on other sites More sharing options...
machf Posted June 17, 2008 Author Share Posted June 17, 2008 Not much, IIRC the other one is older... and I've never been an intensive gamer/programmer/anything. Weird, the older drive is dirtier, so I don't think it's more cleaning that the heads may need... Quote Link to comment Share on other sites More sharing options...
MEtalGuy66 Posted June 17, 2008 Share Posted June 17, 2008 Not much, IIRC the other one is older... and I've never been an intensive gamer/programmer/anything.Weird, the older drive is dirtier, so I don't think it's more cleaning that the heads may need... Naah. I was just asking in terms of wear & tear.. Drive mechs do wear out.. You can compensate for a certain amount of "slop" in the mechanism by "shooting the happy medium" on head allignment, but past a certain point, the whole mech needs to be "rebuilt" which noone does.. (good luck finsing the parts unless youve got another failed unit to take them from). But It doesnt sound like that is the problem here.. Where has this thing been stored? could degredation due to heat/humidity be a factor? Quote Link to comment Share on other sites More sharing options...
machf Posted June 17, 2008 Author Share Posted June 17, 2008 (edited) It wasn't actually stored, it was right here on my desk all the time, where it's been for years, only I haven't been using it in the last two years or so. Right on top of the other one, and with an acrylic diskette storage box on top, at the edge of the desk. A 1050, with another storage box and an XG12 cassette rcorder on top next to it to the right, and then the VHS, DVD player and 800XL on top of them, further right in the middle of the desk, a joystick at the far right... the PC keybpard lies in front of the VHS, with a PC joystick to the left (in front of the 1050) and a mouse to the right (almost in front of the Atari joystick). The PC case lies on the floor, further left from the desk, with extension cords for the keyboard, mouse and monitor, so it isn't a likely source of interference or anything. Weird... I'm not giving up on it yet. Worst case, I can always try hitting it hard, works 99 times out of 100. What I need now is an RPM checker, to verify that the drive is spinning at full speed. IIRC, there was some DOS with one built-in, I wonder if that would work even if the sectors can't be read... UPDATE: SmartDOS 6.1d was it, unfortunately the test didn't work with the drive... any other RPM checkers? Edited June 17, 2008 by machf Quote Link to comment Share on other sites More sharing options...
MEtalGuy66 Posted June 17, 2008 Share Posted June 17, 2008 It wasn't actually stored, it was right here on my desk all the time, where it's been for years, only I haven't been using it in the last two years or so. Right on top of the other one, and with an acrylic diskette storage box on top, at the edge of the desk. A 1050, with another storage box and an XG12 cassette rcorder on top next to it to the right, and then the VHS, DVD player and 800XL on top of them, further right in the middle of the desk, a joystick at the far right... the PC keybpard lies in front of the VHS, with a PC joystick to the left (in front of the 1050) and a mouse to the right (almost in front of the Atari joystick). The PC case lies on the floor, further left from the desk, with extension cords for the keyboard, mouse and monitor, so it isn't a likely source of interference or anything. Weird... I'm not giving up on it yet. Worst case, I can always try hitting it hard, works 99 times out of 100. What I need now is an RPM checker, to verify that the drive is spinning at full speed. IIRC, there was some DOS with one built-in, I wonder if that would work even if the sectors can't be read... UPDATE: SmartDOS 6.1d was it, unfortunately the test didn't work with the drive... any other RPM checkers? RPM.COM in spartados.. Best way to check it though, is with a calibrated adjustable frequency strobe-light... Quote Link to comment Share on other sites More sharing options...
machf Posted June 17, 2008 Author Share Posted June 17, 2008 (edited) RPM.COM in spartados.. I got an "error in read... Aborted" message. Oh, well. Best way to check it though, is with a calibrated adjustable frequency strobe-light... My problem is getting access to one... Edited June 17, 2008 by machf Quote Link to comment Share on other sites More sharing options...
sup8pdct Posted June 18, 2008 Share Posted June 18, 2008 RPM.COM in spartados.. I got an "error in read... Aborted" message. Oh, well. Best way to check it though, is with a calibrated adjustable frequency strobe-light... My problem is getting access to one... Trouble with dos Rpm checkers is that need to be able to read a sector with out errors to work..... Also if they don't take into account the Ntsc Pal difference like some early ones do. James Quote Link to comment Share on other sites More sharing options...
machf Posted June 18, 2008 Author Share Posted June 18, 2008 Just been thinking... tha metal tab protruding to the side at the back of the head "carriage" is what's used to determine the position of track 0, right? So if that's not in the right place, it would be a possible cause... however, I haven't touched it until after noticing the drive had those problems. Quote Link to comment Share on other sites More sharing options...
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