rfancella Posted October 8, 2014 Share Posted October 8, 2014 (edited) Hello All! First time posting, though your forum has helped me in the past modding my 2600. Thanks to all for that! I recently came into possesion of an Atari 1040 STf. I am a Commodore & Amiga guy from way back, so I know little to nothing of the ST series. I was assured there was nothing wrong and it was tested (a one owner machine). Well, it boots to GEM without issue. The floppy (D357) does not spin. Makes no noise other than the head. My question is, could the caps in question cause the drive to not spin? Or is the drive motor just toast? Is there anything I can test or just replace the drive and cut the case? Thanks, Ron PS: Just went digging through my junk pile. Found and old (but great shape) NEC FD1231H. Anyone know if I can mod it and make it work? Edited October 8, 2014 by rfancella Quote Link to comment Share on other sites More sharing options...
TheAtariKing Posted October 25, 2014 Share Posted October 25, 2014 Thank you for sharing this. Quote Link to comment Share on other sites More sharing options...
joedredd Posted October 25, 2014 Share Posted October 25, 2014 My question is, could the caps in question cause the drive to not spin? Or is the drive motor just toast? Possibly motor, but for a couple of quid it's worth trying the caps first IMHO. Quote Link to comment Share on other sites More sharing options...
Maarten Martens Posted November 2, 2014 Share Posted November 2, 2014 Hello all, Anyone of you have any idea what could be wrong with this SF354? I would just like to have it working again. I started a thread over at Atari-Forum. If anyone is willing to have a look and has any idea, please let me know. http://www.atari-forum.com/viewtopic.php?f=15&t=27116 Thanks, Maarten Quote Link to comment Share on other sites More sharing options...
Zap! Posted November 2, 2014 Share Posted November 2, 2014 Hello all, Anyone of you have any idea what could be wrong with this SF354? I would just like to have it working again. I started a thread over at Atari-Forum. If anyone is willing to have a look and has any idea, please let me know. http://www.atari-forum.com/viewtopic.php?f=15&t=27116 Thanks, Maarten Is the belt tight, or did it snap? If all else fails, feel free to sell me your power supply. I have two SF354's and no way to test them. Quote Link to comment Share on other sites More sharing options...
GadgetUK Posted November 2, 2014 Author Share Posted November 2, 2014 OK, so I can see you've taken the FDD out there and stuck it into the STe and it seems no different? ie. presumably you cannot format disks with the STe using that drive like that? Have you tried putting the STe FDD into the external casing and testing that to see if it works when its external? If that works it's clearly the drive and not the housing. In terms of what could go wrong with that drive, there's what looks like a quad flat pack or something - that's my first guess, but there are other passive components on there - a DIP type chip which I cannot tell what it is? Possibly a transistor or resistor has failed somewhere on there? Could you take some close ups of the drive PCB? And test the STe drive in the external unit and then report back. Quote Link to comment Share on other sites More sharing options...
GadgetUK Posted November 2, 2014 Author Share Posted November 2, 2014 That buzzing sounds like the motor which controls the head assembly - I could be wrong but that's what it sounds like to me. Almost like the motor is spinning and the worm / tooth assembly is not engaged, so the head isn't able to move to the correct position. I would try moving the head assembly manually to see if it moves and try to examine the associated drive mechanism there. Quote Link to comment Share on other sites More sharing options...
Maarten Martens Posted November 2, 2014 Share Posted November 2, 2014 Thanks a lot for the feedback GadgetUK, really appreciate it. If you browse through the thread, you will notice I have 3 more movies posted. Please have a look. I did move the drive's head manually. I tested the drive on a 520 ST and today I switched the drive in my STe. I will get back to you with more photo's tomorrow, but please keep in mind I am no hardware or electronics guy, I'm a beginner and I would just love to have this original SF354 working again ... I will also try and put the STe diskdrive in the external unit ... Thanks again. Maarten Quote Link to comment Share on other sites More sharing options...
Maarten Martens Posted November 2, 2014 Share Posted November 2, 2014 I see you have an interesting youtube channel ... will check that one out ... Quote Link to comment Share on other sites More sharing options...
Maarten Martens Posted November 3, 2014 Share Posted November 3, 2014 Hello Gadget, Our analysis (when looking at the AF thread) is also a problem with the motor/head. The head doesn't move at all when booting. The humming noice continues constantly when I reach the desktop, it doesn't stop. I've made some pictures of the drive : top : https://www.facebook.com/photo.php?fbid=10204048212138886&set=a.10204042542637152.1073741832.1031601749&type=1&theater Bottom : https://www.facebook.com/photo.php?fbid=10204048212178887&set=a.10204042542637152.1073741832.1031601749&type=1&theater I'm looking through the service manual, to the motor and head diagrams, but I can't seem to find the worm.tooth you describe : http://info-coach.fr/atari/hardware/fd-hard/ST_SF354_ServiceManual_v2.pdf Any help is very much appreciated. Thanks, Maarten Quote Link to comment Share on other sites More sharing options...
GadgetUK Posted November 3, 2014 Author Share Posted November 3, 2014 My first port of call there would be to clean and test any switches - I see SW1 on the bottom PCB there, not sure if that's a mechanical switch or a Hall effect sensor or something? Test and swap out those 3 electrolytics on the bottom PCB. Test that transistor TR1, and what looks like a transistor array? (TP2). Beyond that, and assuming there's not a physical mechanical fault related to the head assembly I would suspect one of the 2 Mitsubishi chips. Quote Link to comment Share on other sites More sharing options...
GadgetUK Posted November 3, 2014 Author Share Posted November 3, 2014 Very interesting schematics there! It has been a long time since I looked at the FDD interface on these systems and I had forgotten that the WD FDD chip in the ST does most of the work, including controlling the STEP signal. Looking at that service manual that drive doesn't use a worm mech, it looks like the head is connected to a metal tape or something - hard to tell. Try swapping the caps out, and general cleaning of switches, mech parts etc and if that doesn't work I don't think you are going to fix this without an oscilloscope or logic probe. There's a chance that one of those Misubishi chips are faulty and you aren't going to find a spare, unless from a doner drive. Quote Link to comment Share on other sites More sharing options...
GadgetUK Posted November 3, 2014 Author Share Posted November 3, 2014 Also... Are you sure the drive was the right way around (IDC connector) when you had it in the STe? Reason I ask is the LED was on all the time - that happens when the IDC connector is upside down. Different FDDs expect cable the other way around. I am wondering if it was wrong way around in the STe, and the reason it doesn't work externally is a problem with the external housing PCB, OR the cable from the ST - maybe missing STEP signal. Quote Link to comment Share on other sites More sharing options...
Maarten Martens Posted November 4, 2014 Share Posted November 4, 2014 Thanks for the feedback Gadget. I hope to have some more time tonight to do some more tests. I'll keep you posted. About your last remark. Could be I did not connect them correctly, because when I wanted to put the STe internal drive into the external SF354 casing, I noticed both the ports on the internal drive were switched from position compared to the external drive, so who knows ... I will do that test first again ... Cheers, Maarten Quote Link to comment Share on other sites More sharing options...
Maarten Martens Posted November 4, 2014 Share Posted November 4, 2014 Gadget, Thanks for trying to help me. I did another check in the STe, but the drive was connected correctly. I read your posts again, stared at the chips and switches but I just don't have the know how or skills to do any PCB testing. Too bad. I guess this thing will stay unusable for me for a while :-s Anyway, thanks again, and I will be following you on youtube Maarten Quote Link to comment Share on other sites More sharing options...
ors0n76 Posted July 31, 2017 Share Posted July 31, 2017 This is very helpful post. Thank you "GadgetUK". After replacing the caps, my sony MPF110-03 works perfectly again. Quote Link to comment Share on other sites More sharing options...
+remowilliams Posted February 19, 2022 Share Posted February 19, 2022 The drive in a absolutely beautiful 1040STF I picked up recently suddenly stopped working. It didn't dawn on me at first for some reason that capacitors might be related to its failure (it still functioned, but just gave a sad back and forth head stepping of death trying to read anything) Sure enough when I disassembled it, there were visibly bad/leaked caps on it. I never recapped a small floppy drive before but figured what the hell, and voila it's back to life. The big button D357 TDK mech was super easy to work on. Really well put together and almost designed for easy service due to how it was made. Quote Link to comment Share on other sites More sharing options...
Like us on Facebook
Follow us on Twitter
AtariAge on Instagram
Watch us on YouTube
Chat on Discord
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.