Apple //c ALPS floppy drive repair

[tony359]

Hi all,
I'm fixing an Apple //c, the ALPS drive is kind of working but it fails all general tests from MECC and XPS. Also it reports a speed of 400 or 600RPM (depending on when I try) but I am 100% sure the speed is correct as I can see the 50Hz pattern still and I also have a tachometer to check. Might not be exactly 300 but definitely not 600 The pulley spins freely when the belt is removed.

I can boot from that drive and works with most of the software but not all. The same issue happens when connected to my Apple //e.

I'm checking schematics and testing signals but I'd like to understand how the software determines the speed of the drive?

Thank you!

 

[tony359]

Well, I fixed the drive - indeed bad writing amp.

But I broke it again, very frustrating. It was working and I decided to fix the squeaky noise coming from the top plastic basket. I disassembled it, cleaned it, lubricated it and put it back. At first incorrectly, I admit, as I put the conical spring backwards so it got stuck on the metalframe.

I fixed that and... nothing, the drive spins, the heads goes to track zero and nothing. "Check disk drive". The //c works, FEMU boots ok.

The basket spins ok if I turn it manually. I didn't bend the metalframe to the point of no return and the pad which applies pressure on the media reaches the media and applies pressures as expected.

It feels a bit a coincidence that the drive failed when I opened it - but I cannot find anything wrong with the assembly.

Any ideas?

 

[tony359]

I ended up fixing that drive - and many other things.
I made a video out of the repair, any feedback is appreciated!

 

[george]

Its not about repairs, its all about youtube. Disgusting.

 

[tony359]

@george , I checked with the forum if it was ok to post my videos here. I'm sorry my post caused your reaction. Youtube is an hobby for me. Filming those videos multiplies the time it takes to do the repair tenfold.

My intention was to start a thread, a conversation. Get some feedback - good or bad - learn something, realise mistakes. If you check above, I came here asking for help when I was diagnosing that drive.

The last thing I want to do is to be seen as the guy who only posts youtube videos to advertise them.

I'll check with the admins and with the community again, if these posts are not welcome, I won't post them again.

Thanks
Tony

 

[tony359]

I've managed to fix the faulty drive. It's great to see that not all alignments require the alignment diskette! I think I will check my //e drives as well. Let me know what you think!

 

[wowbobwow]

I obviously can't speak for others here, but I love "how to" videos on YouTube! I'm an enthusiastic amateur with repair work, so having a video to follow and refer to has been invaluable to me many times. Having made a couple myself, I appreciate the added time and effort that goes into making videos simultaneously with doing complex repairs - thanks for sharing your knowledge with the community.

That said, your embeds don't seem to be working for me. Could you post a link to your video and/or channel?

Huxley

 

[tony359]

Hi @wowbobwow

Thank you, I appreciate your kind words and also thanks for appreciating the immense extra time it takes to make the video on top of the repair :0

The forum embeds the link automatically I'm afraid, I am not doing anything.

Let me break up the link here so the forum doesn't see it as a link - you'll need to copy it and paste it and remove the space just before "youtu.be" to make it work though. Let me know if that works!

Part 1: https:// youtu.be/Eyc6LraD9O0
Part 2: https:// youtu.be/XfEr9L_oA-0

Thanks!
Tony

 

[tiim]

The embeds work for me inside Chrome. I'm 50/50 with YouTube. Sometimes very informative and it helps me "see" how things are done, while I prefer text half the time, especially if the writing is clear and concise. Videos allow more things to be glossed over.

 

[tony359]

Video is not the perfect media of course. Particularly if one wants to keep the length "reasonable" - considering that nowadays the ideal length is less than 10 minutes! A few friends have suggested I limited my videos to 10 minutes. LOL!