Hey all,
I'm a longtime Apple II user so not totally clueless but definitely not as technically adept as some. I've recently started trying to get a IIc Plus that I've had lying around working again; for as long as I'd had it, it just wouldn't boot. I replaced the ROM chip and now it boots and works fine, except the internal floppy drive doesn't eject via the eject button. The drive otherwise works great; just doesn't eject.
This is an 800K drive, a Sony MP-F51W-03. I've read a lot about these the past few days and have tested the eject switch (with a multimeter), the disk sensor switch, and also checked the eject motor gears. I did notice when I removed it that the eject motor seemed slightly misaligned (I understand it's supposed to be at the 12 oclock position) so I lifted one gear, turned the motor slightly and it turned easily. Then I put the gear back and reinstalled the motor. All seems fine. The drive itself looks great, almost like it was never used. There's no dirt or gunk anywhere and everything moves easily. The drive snaps the disk away quickly when loading and clamps down right away.
There are no sounds at all from the eject motor when I press the button. It's like it's not even trying. The one thing I don't really know how to test is the motor itself; I don't think I have a way to add power to it by itself to see if it works. Or is there some other way to force it to eject? Some way to short it or something?
At the moment I'm suspecting the motor is just dead because I feel like I've ruled everything else out, but I don't know how to rule the motor in or out. Or is there anything else I'm missing?
I can use the computer as is by just using the manual eject pinhole, or by using my Floppy Emu. But I'd just love to get this uncommon Apple II back up and running 100%. I feel so close, but just can't figure out this one thing.
Thanks for any help!
P.S. I'm definitely open to just replacing the motor or drive if anyone wants to part with one; they're not all that easy to find.
check the gears in the ejection module and see if any of the gears have cracked. that's a very common problem with sony drives; the gears would fail after decades of exposure to the lubrication they used at the factory.
I've checked all the gears, they're fine, look brand new... I've checked all the common stuff like that. Anything else it could be beyond the stuff I mentioned? Or is it most likely just a dead motor?
Back in the 1990s, we used to repair these in bulk. Ejection motor failures were common; as were analogue board faults, with the drives that we received. Chck to see if the connections to the ejection motor on the analogue board are intact, and for cold joints there. If not, try replacing the motor.
Note that the button for the ejection on the //c+ is not part of the drive mechanism itself.
is the microswitch behind the ejection button still good? are the wires runnig from the switch to to the main board still good?
That's a good point. That is a momentary switch, and you should be able to manually bridge those pins to see if they cause an eject. If not, look at their solder paids and traces.
If you have an Apple 3.5 (800K) drive from a //e or a //gs, the mechanism is identical. You can use most 51W mechs in the //c+.
I checked the pins with a multimeter as part of testing the button switch and they measured fine (continuity with the button pushed, no continuity without it pushed). It was possible to partially plug the switch in so I could actually measure from the pins on the motherboard without removing the motherboard. So I don't think I need to try shorting those pins because I technically did as part of that test.
I have not checked the solder pads and traces from those pins, though. I guess I will try that next. I would be massively surprised if the problem is on the motherboard, though; this thing looks like it was made yesterday. It looks like somebody bought it and just immediately put it in a closet until I got it last year. But I know cracked solder joints can happen for any number of reasons, so I guess it can't hurt to check before I totally give up on it.
Ok, I did check all the solder points and traces from those two pins on the motherboard, and the motherboard is totally fine. (One pin goes to a couple of capacitors, the other goes to the top right pin on the floppy connector). I couldn't get to all the points on the drive board, but at this point I'm about ready to just give up and call it a bad motor. It's still just not even trying.
So I guess I will be in the market for a new drive or eject motor. Are the external 800K drives for the IIGS a straight replacement, or do they at least have the same eject motor? I used to have two of those and still should but I may have lost them in a move... so I can look again for those or I may just look to buy another one if it's the exact same drive or at least eject mechanism.
They are the same mechanism. If you buy them used, they will probably be awful. You may want to contact Herb Johnson to order a refurbished mech. He has a few of the 800K mechanisms left in stock.
I would offer one, but I have a two foot stack of the to go through, and I won't have them ready in a hurry. If you want to send in your mech for repair or restoration, I suppose I could do it. I have plenty of spares for them, but it won't be super-fast.