Greaseweazel and Fujitsu M2551A woes

[btb]

I have a Fujitsu M2551A, 360K floppy drive. I want to use it for writing images to disk using my Greaseweazel device. In fact, I did successfully write one disk with it, but now I can no longer get the spindle motor to turn. I can still make the head seek just fine.

Other drives still work fine on the Greaseweazel.

The Fujitsu still works fine when hooked up to a regular floppy controller.

I thought maybe I did something to damage/weaken the Greaseweazel's Motor-On output, but just using a multimeter, I can see that pin 16 drops from 5V to zero when the motor is supposed to spin. Perhaps there is there a different signal I should be looking at?

Could this be a symptom of capacitor aging?

 

[ldkraemer]

Are you sure the Fujitsu M2551A is a 360K, 5.25" Floppy Drive. The documentation shows it as a 3.5" 720K Floppy Drive.




Larry

 

[btb]

I came across that too, while looking for documentation. It's definitely wrong - this is a 5.25" drive

 

[Gary C]

It would normally be a jumper issue.

what happens if you plug the connector in upside down ?

 

[syzygy]

My Fujitsu M2551A 08 is a 360K, 5.25" Floppy Drive. Here it is when I first got it and before I cleaned it up. Your logic board may look different.



One possibility is that you have a two drive twisted cable on your Greaseweazel and you have inadvertently plugged the drive into the wrong connector. You should use the first connector on the cable. I don't use this drive on my Greaseweazle, but as I remember, when I inadvertently plug a drive into the wrong connector (I normally use the first connector) on the cable, it behaves as you have described.

 

[btb]

Mine looks just like that. I’ve tried before and after twist, and every position of the DS jumper. I only recently figured out I needed to install the termination resistors, but that also hasn’t made a difference.

 

[btb]

Another obvious thing to check is the power I guess. I am using an external supply, since the GW can’t supply 12V. But that could be flaky, I should try another one.

 

[syzygy]

I was hoping that it was the cable position. Let us know when you get it squared away.

BTW: I have never found anything like a service manual for the drive. All I have is this product brochure which lists a few specs.

 

[Gary C]

Have you tried plugging the connector upside down ?

Seriously, what happens is it pulls the drive input signals down to ground and the disk should be selected and the motor spin. If it doesn't, then its the drive.

 

[btb]

ugh, it's working now. I was trying the upside-down cable thing, no spin. Put it back on the Compaq Portable II where it had been working fine before, but now I was getting no spin. Turned it on its side, and saw that the cable connecting the spindle board to the main board had come out. It's just four bare wires going into a kind of friction fitting, and it isn't holding tight at all. Mystery solved, I hope.

 

[btb]

On the bottom of the drive:


This white connector:




I think just figured out how it works. There is two parts, one is firmly connected to the board, the other is like a little cap, it’s the right half in this photo. The cap is actually a release button. Press it and the terminals inside separate and no longer bite down on the wires. Mine was jammed down hard so the wires wouldn’t stay put.

And yes, the drive is working as it should now.

 

[Gary C]

AH, that wouldn't help !