Help hacking and restoring AX-350II sakhr | MSX Resource Center (Página 5/18)

Master (198)

06-02-2018, 10:16

maxis wrote:

ali6x944 wrote:

I opened the drive and checked the voltage and it is fine, I really don't know what is the problem...
I really need some help here if any one has the same drive or knows how to fix these drives post about it please,
Your post is highly appreciated.

When the drive is accessed does it spin? When the drive is out of the computer try slowly turn the screw for the head servo left/right. Do it by hand in order not to scratch the head screw shaft. Turn the spindel motor by hand too. Likely head servo is stuck.

Take the 720K floppy, format it in PC and then try to put it in MSX. In MSX basic try FILES, see if it says DISK OFFLINE or something else....

One more thing -> once drive is out of MSX, spin the head servo motor by hand to push the head into the middle tracks (not first 2-3 tracks). Then put back the drive,connect it and power up the MSX. The head must be displaced automatically to track 0 after reset to FDC. You will see and hear it.

Well, the drive is used to show drive offline when I do a "call format", I should note that the indicator light of the floppy drive doesn't light up.
I disconnected the floppy and reconnected it again with no results but what you saw in the images.
For the spindles I turned the floppy motor spindle and it spins nicely, the head however is a bit tough

Por ali6x944

Master (198)

06-02-2018, 18:18

I was hopping to update my system to SymbOS.3 or something if it wasn't for the floppy drive!!!

Por maxis

Champion (512)

06-02-2018, 21:32

ali6x944 wrote:

the head however is a bit tough

Well, maybe that's the answer - your floppy head stepper motor is stuck... Try to unseize it with a tiny drop of WD40 on the ball bearing of the stepper screw. The technique to use -> make a "drive belt" out of the narrow rubber strip, put around screw and turn it by the rubber belt... Once the movement is light, again, take all the gunk with cotton swabs. See if the floppy will start working back again. If it does then reapply the long lasting white grease to the bearings.

Por ali6x944

Master (198)

07-02-2018, 08:03

maxis wrote:

ali6x944 wrote:

the head however is a bit tough

Well, maybe that's the answer - your floppy head stepper motor is stuck... Try to unseize it with a tiny drop of WD40 on the ball bearing of the stepper screw. The technique to use -> make a "drive belt" out of the narrow rubber strip, put around screw and turn it by the rubber belt... Once the movement is light, again, take all the gunk with cotton swabs. See if the floppy will start working back again. If it does then reapply the long lasting white grease to the bearings.

Did it and still the drive doesn't work or spin or respond...

Por maxis

Champion (512)

07-02-2018, 11:37

ali6x944 wrote:

Did it and still the drive doesn't work or spin or respond...

So, when you are accessing the drive and or pressing the RESET the drive doesn't spin? When you insert the floppy, does it try to make a very short spin? Check with the oscilloscope whether you have a STEP pulse (pin 20 on the 34pin connector) when you move the head in the middle of the disk and then press RESET. Mind you that the FDC reset sequence will step the disk until TRACK 0 is reached (pin 26 is #TRACK0).

Por ali6x944

Master (198)

07-02-2018, 16:26

maxis wrote:

ali6x944 wrote:

Did it and still the drive doesn't work or spin or respond...

So, when you are accessing the drive and or pressing the RESET the drive doesn't spin? When you insert the floppy, does it try to make a very short spin?

nope, it doesn't at all.

maxis wrote:

Check with the oscilloscope whether you have a STEP pulse (pin 20 on the 34pin connector) when you move the head in the middle of the disk and then press RESET. Mind you that the FDC reset sequence will step the disk until TRACK 0 is reached (pin 26 is #TRACK0).

dose msx computers have special pinout for the floppy drive?

Por maxis

Champion (512)

07-02-2018, 18:10

ali6x944 wrote:

dose msx computers have special pinout for the floppy drive?

Depends on the vendor. Panasonic - special connector. Yamahas - normal connector. Your drive has the separate power connector, so then the pinout is standard.

Por ali6x944

Master (198)

07-02-2018, 19:43

maxis wrote:

ali6x944 wrote:

dose msx computers have special pinout for the floppy drive?

Depends on the vendor. Panasonic - special connector. Yamahas - normal connector. Your drive has the separate power connector, so then the pinout is standard.

the AX-350II is manufactured by Yamaha, and the drive is made by Toshiba so is the connector a standard PC connector?
from what I understood it has a standard PC connector, is this right?

Por maxis

Champion (512)

07-02-2018, 20:41

ali6x944 wrote:

from what I understood it has a standard PC connector, is this right?

That's right

Por Wierzbowsky

Guardian (3606)

07-02-2018, 22:04

Please keep in mind that on some floppy drives it's possible to connect the cable upside down. If the cable is connected incorrectly, then there may be serious consequences. Some drives will ignore this, but some may start smoking. I've seen this with one of my drives (luckily it survived).

Example:

So it's good to first check the continuity of the entire floppy cable. And then it makes sense to verify that the ground pins on the motherboard's floppy connector are connected to the ground pins on the floppy drive. In the floppy connectors only one row is used for signals, the other row is used for ground, so it's easy to check.