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Inherited a Macintosh Plus 1986 with floppy drive issue

cendrick

Member
Hello everyone.

Thank you for reading and for watching the linked video.
My new inherited 1986 macintosh plus was working great. I was playing some games on it which took me back to my childhood and upon exiting a game, the disk did not eject fully and a humming noise began at the same time. The disk will not eject and when I manually eject it the humming noise continues. No disk can be inserted into the drive anymore. It does not go down into the lower position. Would this be a simple cleaning issue or could it be those motor cogs which I've heard need to be replaced in certain cases.

Regards,
Rick

video showing the issue
 

Phipli

Well-known member
Hello everyone.

Thank you for reading and for watching the linked video.
My new inherited 1986 macintosh plus was working great. I was playing some games on it which took me back to my childhood and upon exiting a game, the disk did not eject fully and a humming noise began at the same time. The disk will not eject and when I manually eject it the humming noise continues. No disk can be inserted into the drive anymore. It does not go down into the lower position. Would this be a simple cleaning issue or could it be those motor cogs which I've heard need to be replaced in certain cases.

Regards,
Rick

video showing the issue
Yeah, sounds like the gear failed.

You'll want to find a gear for an 800k floppy and fit it.

Perhaps this :


Or this :


I don't have experience with either, but you'll want to clean and lubricate the drive at the same time. There are several videos on how in YouTube.
 

Phipli

Well-known member
Be careful when you take the Plus apart. Do not run it before you dismantle it (I usually leave it off for a day at least). Take a lot of care around the back of the CRT, if you knock it, you can very easily break it and it can hold high voltage. The vertical board on the left hand side (from front) can also contain high voltages, so I usually keep my hands off it just to be on the safe side.
 

cendrick

Member
Yeah, sounds like the gear failed.

You'll want to find a gear for an 800k floppy and fit it.

Perhaps this :


Or this :


I don't have experience with either, but you'll want to clean and lubricate the drive at the same time. There are several videos on how in YouTube.
Excellent. Thank you for the confirmation that was the issue and for the links. I'll get those ordered and hope for the best;)
 

cendrick

Member
Be careful when you take the Plus apart. Do not run it before you dismantle it (I usually leave it off for a day at least). Take a lot of care around the back of the CRT, if you knock it, you can very easily break it and it can hold high voltage. The vertical board on the left hand side (from front) can also contain high voltages, so I usually keep my hands off it just to be on the safe side.
Thank you for the tip. Yes, I've seen some videos where many discharge the voltage. Do you suggest that as well or is it safe, if you are careful, to remove the motherboard and then the floppy with out discharging the crt?
 

finkmac

NORTHERN TELECOM
In my experience the issue is more likely to be dry lubricant and other gunk gumming up the drive rather than the gear. Although it's good to have it and be prepared!

Watch this video, good tutorial on lubrication.
 

Phipli

Well-known member
Thank you for the tip. Yes, I've seen some videos where many discharge the voltage. Do you suggest that as well or is it safe, if you are careful, to remove the motherboard and then the floppy with out discharging the crt?
Truth be told, for this I wouldn't specifically discharge. You can keep away from them if you're careful to remove the drive.

You don't need to remove the logic board (motherboard).
 

Phipli

Well-known member
In my experience the issue is more likely to be dry lubricant and other gunk gumming up the drive rather than the gear. Although it's good to have it and be prepared!

Watch this video, good tutorial on lubrication.
Not in this case - you can hear the motor spinning because the mechanism isn't returning to its home position.
 

cendrick

Member
In my experience the issue is more likely to be dry lubricant and other gunk gumming up the drive rather than the gear. Although it's good to have it and be prepared!

Watch this video, good tutorial on lubrication.
Great! I hope you are correct and I'll get that gear just to be on the safe side once I open it up:)
 

cendrick

Member
Truth be told, for this I wouldn't specifically discharge. You can keep away from them if you're careful to remove the drive.

You don't need to remove the logic board (motherboard).
oh! I thought the screws holding the floppy casing in place was blocked by the motherboard. Do you have a video link that may show the process? And thank you for your help on this.
 

Phipli

Well-known member
oh! I thought the screws holding the floppy casing in place was blocked by the motherboard. Do you have a video link that may show the process? And thank you for your help on this.
Hum, I might be mistaken. I was assuming it was going to be like taking a floppy drive out of an SE (the replacement model), but that is a different arrangement. Sorry about that :) I should have thought more.

Regardless, there are no high voltages on the logic board, so you'll be fine.
 

cendrick

Member
Hum, I might be mistaken. I was assuming it was going to be like taking a floppy drive out of an SE (the replacement model), but that is a different arrangement. Sorry about that :) I should have thought more.

Regardless, there are no high voltages on the logic board, so you'll be fine.
Excellent. I appreciate that clarification;)
 

cendrick

Member
Update:
Hello everyone. My repair is going well. Took the mac case off, took of the floppy drive and found the stripped gear. See photos below. I now have a new issue. As I was cleaning the drive, I took the extra initiative to clean the lower plate but one of the metal clips flew off the stud and is nowhere to be found. Any ideas on how to replace this?
Mac-motor-gear.JPEGmetal-clip.JPEG
 

Phipli

Well-known member
Probably easier to keep looking. I shine a torch at low level over the floor so it casts long, visible shadows.
 

croissantking

Well-known member
I've certainly been down on my hands and knees a number of times. It's always that one component that flies off. The worst thing is the gaps between the floorboards that I have.
 

Phipli

Well-known member
I've certainly been down on my hands and knees a number of times. It's always that one component that flies off. The worst thing is the gaps between the floorboards that I have.
I don't bother removing those washers, you can flush out the old grease with IPA and place new grease strategically to get most places, and the mechanism has then moved freely enough.

My SE drive :

 
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