Mac128K internal floppy disk problem

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Mac128K internal floppy disk problem

Hi,

I have a Mac 128K that seem to have a problem with the floppy disk drive. When I insert the floppy, it won,t enter correctly.

I realized that the top-metal plate of teh disk drive is somehow down too much to work properly. In fact, the metal plate is visible from the outside of the Mac plastic, which sound not normal.

How can I repair this?

Thanks

PB 12", Beige G3, G4 Cube, Mac II, SE/30, 128K and a few more, Mac OS X (10.4.8), iLife 06

Posted on Jan 6, 2007 7:11 PM

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Answer 1

Jan 7, 2007 4:13 AM in response to Steve-Mac-

Hi Steve,

You'll need to take the Mac128k apart, which is easier said than done.. You will need a long Torx driver.. if you don't have one that can reach, remove the two screws at the bottom of the back of the case and take them to an auto-parts place to find a driver long enough to remove the identical screws from inside the handle. Once it is apart, be very cautious of the picture tube and the analog board. These can retain charge for quite some time.

Once you get it apart, remove the drive mechanism, then apply a small amount of grease or other mechanical lubricant to the parts of the mechanism that move to accept the disk and try making the mechanism move by inserting a disk. In the 23 years since they were built, the grease dries out and causes the drive to stop working. I have a 128k, 512k and MacPlus, and I've needed to re-grease all the drives in the last few years.

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Answer 2

Steve-Mac- Author

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Jan 7, 2007 5:58 AM in response to Alex Dawson

Hi,

You'll need to take the Mac128k apart, which is
easier said than done.. You will need a long Torx

I managed to find a way to remove the case already. That was a good way to validate that all the signatures were in the back of the case 🙂

inside the handle. Once it is apart, be very cautious
of the picture tube and the analog board. These can
retain charge for quite some time.

I know they are sensitive... The MB has been removed already too.

Once you get it apart, remove the drive mechanism,

That is where I'm jammed. How do I do so?

mechanism move by inserting a disk. In the 23 years
since they were built, the grease dries out and

A little bit like the eMate hinge.

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Answer 3

Jan 7, 2007 6:28 AM in response to Steve-Mac-

From memory.. there are four screws pointing upwards into the section of the chassis that holds the drive, that are revealed when the logic board is removed. That entire section then comes out, and the drive can then be removed from that retainer.

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Answer 4

Steve-Mac- Author

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Jan 7, 2007 8:48 AM in response to Alex Dawson

From memory.. there are four screws pointing upwards
into the section of the chassis that holds the drive,

I saw them, just after removing the chassis that hold the drive itself! Too late 🙂

That entire section then comes out, and the drive can
then be removed from that retainer.

I have it in hands now. Now the question is: what to do next? I tried inserting a disk manually into the drive, but I cannot managed to see what are the movings parts of the drive assembly. All looks to be very jammed...

Also, the chassis that holds the drive has some rust on the side that is nearby the power supply. I think, while I'm there, it should be a good idea to clean that. What would be the best?

Thanks again.

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Answer 5

Jan 7, 2007 2:09 PM in response to Steve-Mac-

Lightly spraying something like WD40 onto some of the areas that had grease should get them moving again.. from memory, on the sides are some small pieces of metal that move. When spraying, make sure you miss the drive's electronic components. Once it's moving slightly, try to insert a disk at try to work out what should be moving and what isn't.

As for the rust, that's up to you 🙂

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Answer 6

Steve-Mac- Author

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Jan 7, 2007 3:00 PM in response to Alex Dawson

Lightly spraying something like WD40 onto some of the
areas that had grease should get them moving again..

I've tried WD40 and Jig-a-loo, which normally have some effect, but nothing. It is really jammed...

from memory, on the sides are some small pieces of
metal that move. When spraying, make sure you miss

From what I'm seeing there is a metal harm that is attach to a small rotating motor (the eject mecanism). One end of this arm is the little plate we're suppose to push with a trombone to force eject the disk. That even don,t move a bit.

Along this arm, there is some headless screw that are in places in holes that suggest they can move trough. It is really jammed there, nothing want to move!

the drive's electronic components. Once it's moving
slightly, try to insert a disk at try to work out
what should be moving and what isn't.

I suppose it should move even if the drive is not plugged in the board, right?

As for the rust, that's up to you 🙂

I used WD40 to remove some of it. Better than nothing. But that's strange that rust has come to this place. It must have been left into a wet place.

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Answer 7

Steve-Mac- Author

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Jan 7, 2007 3:40 PM in response to Alex Dawson

Hi,

Finally, I got it....

The mecanism was so jammed that I had to apply WD40 many times to get it to move. The part that eject the the disk was also in the same jammed situation.

After that I did put (and clean) a little bit of white lithium grease on the mecanism to help it work for a longer time.

Now, that is a major problem, it no longer boot or display the "Insert disk" icon. I suppose I did something bad to the power supply while doing my job!

I hear a repeatitive click when I put the switch on. Any idea what it can be?

Thanks

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Answer 8

Steve-Mac- Author

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Jan 7, 2007 4:48 PM in response to Alex Dawson

Forgot the preceding message. False alarm!!!

I just forgot to plugged back the power supply to the MB, so it was not booting up for a good reason!

But, as for the drive is concerned, it does not seam to work better. I mean, it do not even spin. I put the disk in, but nothing.

As far as I remember, there is only the flat cable going to the drive, so the power should come from there, right?

I must say, that drive was really stucked... It was working not too bad when I had it in my hand, but now it barely can eject the disk correctly. At least, it can accept teh disk when "forced" gently.

Any other idea?

Thanks again!

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Answer 9

Jan 7, 2007 4:50 PM in response to Steve-Mac-

Hmm did you plug the floppy disk in the correct way around, and did you plug the analog board into the logic board correctly?

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Answer 10

Steve-Mac- Author

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Jan 7, 2007 4:54 PM in response to Alex Dawson

Hmm did you plug the floppy disk in the correct way
around, and did you plug the analog board into the
logic board correctly?

I think we did post at the same time!!!

Yes I plugged the 2 in the correct side. Anyway, for the floppy there is only one side possible with the little notch. And the cable is so short that it is impossible to plug one side on the reverse side of the other.

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Answer 11

Jan 7, 2007 5:12 PM in response to Steve-Mac-

Yes, there is only one cable from the drive to the logic board. Is it plugged in firmly on the drive side as well?

There may be some other parts that need lubrication. It should not be stiff at all when inserting or ejecting the disk. From memory (this was about 4 years ago), I detacted the mechanical and electrical parts to work lubricant through the mechanical parts until there was almost no friction, then cleaned up any excess and put it all back together again.

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Answer 12

Steve-Mac- Author

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Jan 7, 2007 6:16 PM in response to Alex Dawson

Yes, there is only one cable from the drive to the
logic board. Is it plugged in firmly on the drive
side as well?

In between my messages, I removed the drive unit again, and I make it work oprperly. That was the part that help eject the disk (push it out) that was stayed stucked... I did not make too much attention to it.

I also validated and all the cables are plugged correctly, now.

There may be some other parts that need lubrication.
It should not be stiff at all when inserting or
ejecting the disk. From memory (this was about 4
years ago), I detacted the mechanical and electrical
parts to work lubricant through the mechanical parts
until there was almost no friction, then cleaned up
any excess and put it all back together again.

I took my finger and tried make the spin weel turned, and it worked, manually that is. So I do not understand why the drive is not spinning.

There may be the possibility that the mecanism being jammed, the motor and other electronics parts that help the drive work has been dammaged (I mean, they may have force too much and killed themselves). What do you think of that, by experience?

Another possibility, is that the floppy controller is dead, but that will make the MB a scrap too. If I had an external floppy drive, I could validate that part, but I don't.

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Answer 13

Steve-Mac- Author

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Feb 23, 2007 4:37 PM in response to Steve-Mac-

I did anything to save the internal drive, but nothing so far.

So I bought a 400K external drive for the 128K.

Does the Mac 128K can boot from an external drive?

Because when I tried the Mac did not boot at all from the external drive. In fact, the drive did not even try to read the floppy from what I can see.

Any idea?

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Answer 14

Feb 24, 2007 3:13 AM in response to Steve-Mac-

It should boot from the external drive. That might need oiling too! 😀

You should be able to transplant the drive mechanism from the external case to the inside of the 128k.

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Answer 15

Steve-Mac- Author

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Feb 24, 2007 12:01 PM in response to Alex Dawson

It should boot from the external drive. That might
need oiling too! 😀

I don't think so, as the disk is ejecting (with the small hole) normaly. and, further more, the seller told the unit was tested and working.

You should be able to transplant the drive mechanism
from the external case to the inside of the 128k.

I know. I also have a few units I find found cheap, untested, but they may be good for internal replacement.

I'll test it further next week...

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