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Test Mac Plus floppy drive while external?

tomcrete

New member
In trying to sort out issues with the Mac Plus floppy drive, I was thinking it would be great if I could actually see what's going on in the drive. So I pulled the floppy drive and have it sitting outside the Plus. I haven't plugged it in yet as I wanted to get some feedback first in case this is a really bad idea. The drive is sitting upright as it normally would and it's resting on wood. It's not making any other contact other than the ribbon cable. I recall reading that I _don't_ want to do something like have a grounding jumper from the drive to the chassis of the Plus but wouldn't the drive screwed into the case that's screwed into the chassis normally provide the ground?
 

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mdeverhart

Well-known member
It should be fine. The drive electronics are grounded through the cable. I tested a drive for my SE the same way the other day.
 

volvo242gt

Well-known member
It's fine. As long as the board doesn't short out against metal (like I mentioned over at TD), you'll be fine.
 

tomcrete

New member
It went well enough. I was able to see that one noise was the disk spinning (thought that's what it was but was nice to get visual confirmation). The other noise I thought might be related to the eject having trouble but I can see that the eject motor isn't getting triggered. I pulled the eject mechanism out (but still wired), removed the back plate, and removed the gear to expose the little drive gear. Even with mouse button down on startup, the drive gear didn't turn. The repeating noise I was hearing seemed to be coming from towards the front of the floppy drive rather than the rear where the eject mechanism sits. So I've got the issue of the disk not being read as well as the eject issue. This sound like something that recapping might resolve? Here's short vid so you can hear it...
 

volvo242gt

Well-known member
It's the stepper motor moving the head assembly, trying to find track zero. Loosen up the bracket for the ZTS, then adjust it until it starts loading the disk. With respect to the eject motor assembly, you may just have a dead motor, too. I have one early style eject motor assembly that doesn't operate on any of my drives.
 

Hunter259

Member
I've attempted moving the ZTS the little I can with no change. I've manually blocked the sensor out of position and can confirm the sensor is working but again no head movement. I guess I managed to get two of these drives with the same failure.
 

volvo242gt

Well-known member
In your case, you may need to adjust the stepper motor, by loosening its screws and rotating it. Sometimes, the stepper motor will get the head stuck at one end of its jackshaft. I have a FDHD drive in my SE that has that problem. Luckily, I have another in there that works fine, except for a slowly moving floppy disk cage, so it needs some more cleaning and lubrication.
 

Hunter259

Member
May have found the issue. Somehow this machine has an original floppy with black letter MFD-51W and the new one I got is also a black letter MFD-51W-10 but the machine has a yellow cable. Must have been messed with before it got to me.
 

volvo242gt

Well-known member
Yeah, you'll need a 590-0167 cable. The yellow cable has one or two of the pins in the 20 pin connector disconnected.
 

Hunter259

Member
No dice. The friend I got the machine from also got a SE from the same person. Somehow that machine had a red label drive with a red cable. Put in mine and worked right away. No idea on the other drives. He wants to recap the SE before turning it on (I did the same).
 
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