Toshiba T3200 floppy drive problems

[MeepsterNotchy]

I have just received my Toshiba T3200 from eBay, and it works great! Boots up, all the programs work fine, but the floppy drive doesn't work one bit. It came with a stack of (presumably) blank unlabeled disks, and I tried with my own DD disks, but it always says "Error reading drive A: Abort, Retry, Fail?"
If I type cd A:, dir A:, or chkdsk A: it all gives the error message.
I have a working floppy drives around (wrong color though :roll and was wondering if the floppy drive was proprietary or used a standard 34 pin interface?
Help much appreciated!

 

[krebizfan]

IIRC, the T3200 uses a 26 pin floppy which was common on Toshiba laptops. Pull the drive and give it a good cleaning. You have nothing to lose and sometimes the problem can be as simple as dust jamming a sensor. Of course, if the heads are ripped off, the drive will not be fixable.

 

[modem7]

The information at [here] indicates that the T3200 has a 'A/B/PRT switch' at its rear.
Is that set to its default setting: PRT

"Computer must be re-booted for switch change to take effect."

 

[MeepsterNotchy]

It was set to A, changed it to PRT.
Worked like a charm, amazing how simple some things can be!
Also, modem7, your website has helped a lot with various things, I thank you very much!

 

[modem7]

Also, modem7, your website has helped a lot with various things, I thank you very much!

And a thank you to all the contributors.

(SomeGuy has just sent me some more ROM images to add.)

 

[shawnerz]

This thread have been a savior. I normally mess around with the Grid and Gridcase models. But I was browsing eBay and came across a T3200. I bought it. It doesn't have a manual. When I powered it up, it made a bad smell. The unit is not easy to take apart. Tore in to it, I got it apart, and had to replace 3 power supply caps. I got it back together. And then, the floppy drive wasn't working. I Googled the problem and came here.

I put it to PRT and the floppy is working. Yay!

Does that switch route an IRQ to one device?
Thanks,
-Shawn

 

[eswan]

The switch changes the parallel port to be Printer/Floppy A:/Floppy B:. Also switches the internal drive from A: to B:.

 

[shawnerz]

The switch changes the parallel port to be Printer/Floppy A:/Floppy B:. Also switches the internal drive from A: to B:.

I was too early in my celebration. The hard drive still works. I removed it from the chassis. The floppy drive only spins when the switch is in the 'A' position. I have a two different MS-DOS 3.3 boot disks and a MS-DOS 5.0 boot disk. After attempting to read the disk, I get an error saying it wants a system disk and to press any key. It's not unreasonable to think the drive heads might be bad. But do you have any other ideas?
Thank in advance.
-Shawn

 

[modem7]

But I was browsing eBay and came across a T3200. I bought it. It doesn't have a manual.

But subsequently, you would have seen the information pointed to in post #3 above.

People tend to abbreviate. Is it an actual T3200 you have, or is it a T3200SX, or a T3200SXC ?

 

[modem7]

I put it to PRT and the floppy is working. Yay!

So before, when you wrote that, the switch was in the PRT position (which is the default setting), and the internal diskette drive was working. Presumably, at that time, you booted from the hard drive and then successfully read a diskette. Is that correct?

BTW. In the T3200 document at [here], I see that early models have a 720K drive and later models have a 1.44M drive. What does your T3200 have?

I was too early in my celebration. The hard drive still works. I removed it from the chassis. The floppy drive only spins when the switch is in the 'A' position. I have a two different MS-DOS 3.3 boot disks and a MS-DOS 5.0 boot disk. After attempting to read the disk, I get an error saying it wants a system disk and to press any key. It's not unreasonable to think the drive heads might be bad.

I am puzzled. If you have removed the hard drive, what drive are you booting from?

But do you have any other ideas?

A question is, "Is it valid to remove the hard drive?" The Toshiba BIOS might be written to expect it.

 

[eswan]

The floppy drive only spins when the switch is in the 'A' position.

If you don't have an external Toshiba floppy drive plugged into the computer's female DB25 connector the switch should be in the 'PRT' position. If it is set to 'A', the internal drive becomes B:, and unbootable.

 

[shawnerz]

But subsequently, you would have seen the information pointed to in post #3 above.

People tend to abbreviate. Is it an actual T3200 you have, or is it a T3200SX, or a T3200SXC ?

It is a T3200, no additional letters on the front bezel. The model number sticker on the bottom says PA3079U. It has a '286 and I dropped in a '287. Not that I'd actually use the '287 for anything. But it's there...adding just a little bit more load to the power supply.
Oh, I did read about the reboot needed for the switch position to take effect.
Thanks for the info,
-Shawn

 

[shawnerz]

So before, when you wrote that, the switch was in the PRT position (which is the default setting), and the internal diskette drive was working. Presumably, at that time, you booted from the hard drive and then successfully read a diskette. Is that correct?

BTW. In the T3200 document at [here], I see that early models have a 720K drive and later models have a 1.44M drive. What does your T3200 have?


I am puzzled. If you have removed the hard drive, what drive are you booting from?


A question is, "Is it valid to remove the hard drive?" The Toshiba BIOS might be written to expect it.

I unplugged the MFM connector from the Fujitsu hard drive and the power connector to the hard drive. After a minute to 90 seconds, the computer makes 3 long beeps and shows an error on the screen that there's an error reading from the hard drive. Then it says to hit any key to boot. At that point, it tries to read from the floppy, and fails.

The drive is 1.44M drive. It is printed on the disk eject button.

I was attempting to force the Toshiba to boot from a MS-DOS bootable floppy. I wasn't sure if there was something on the hard drive that was preventing it from booting from floppy. Yes, I know that it reads from the floppy before reading from the hard drive. But, I just wanted to be sure. The hard drive has MS-DOS 4.0 (yes, 4.0) on it and looks like it was used by Ameritrade.

When DOS does boot the machine, I try to go to a:\. DOS accepts it, but if I do a 'dir' I get the Abort, Retry, Fail message. I have never been able to read any diskette in the floppy drive. I tried both 720k and 1.44M disks. The disk spins, the heads retract to track 1, and the LED lights.

I thought maybe Ameritrade's software did something to prevent the floppy from being used as some sort of security measure. It would be futile since there are I/O ports, but whatever. Just thought I'd try disconnecting the hard drive and seeing if I could force it to boot from floppy.
At this point, I'm thinking the heads are bad, or something is wrong with the interface.
Thanks for the suggestions.
-Shawn

 

[modem7]

I have never been able to read any diskette in the floppy drive.

You can understand my confusion. Your "working" in post #6 gave me the impression that the drive was working then.

I tried both 720k and 1.44M disks. The disk spins, the heads retract to track 1, and the LED lights.

When you had the unit apart, did you re-seat the diskette drive cables ?

It might pay to remove the diskette drive and do a thorough visual inspection of it; you may spot a problem.

I hear that bad capacitors are common in PS/2 diskette drives. And I encountered bad capacitors in both my 8" floppy drives. It maybe the same with your diskette drive.

It's not unreasonable to think the drive heads might be bad.

I'm sure that if you had a 3.5" diskette drive cleaning kit, you would have mentioned it.

 

[shawnerz]

You can understand my confusion. Your "working" in post #6 gave me the impression that the drive was working then.


When you had the unit apart, did you re-seat the diskette drive cables ?

It might pay to remove the diskette drive and do a thorough visual inspection of it; you may spot a problem.

I hear that bad capacitors are common in PS/2 diskette drives. And I encountered bad capacitors in both my 8" floppy drives. It maybe the same with your diskette drive.


I'm sure that if you had a 3.5" diskette drive cleaning kit, you would have mentioned it.

Yeah, my post was a bit misleading. I saw the disk spinning and the LED lighting, and I thought it was working. I made the post, and went to bed. Only to find that the drive wasn't actually reading data from the disk.

The Toshiba is still apart and the cable has been reseated several times. No problems spotted.

The capacitors being bad is not a bad idea. Because they are just a few uF's, I wouldn't think they'd be *that* bad. But they could be and it's not unreasonable. They do not look to be bulging or leaking.

I do have a 3.5 cleaning disk. I did apply a few drops of alcohol and give it several spins and let things dry. No changes.

Thank you for all of the ideas.
-Shawn

 

[shawnerz]

I thought I was on to something. The short version of the story is I found a tantalum capacitor on the motherboard that was shorting the -12V to ground. I replaced the tantalum with an electrolytic. The voltage is now steady at -12V but as before, the floppy drive still does not work properly. The disk turns, the red light comes on, and the head can move. But the computer fails to read, or boot from the floppy. I eventually get the famous Abort, Retry, Fail error. I tried to format a disk and I got a "Drive Not Ready" error. At some point during my testing, I did get a "Failure on Int24" error. It seems replacing the cap made no difference.
A component on the floppy drive is probably bad. It wouldn't be a big deal if MFM floppy drives were as abundant as IDE floppies are.
Any ideas are welcome.
Thanks,
-Shawn

 

[Conventional Memories]

I thought I was on to something. The short version of the story is I found a tantalum capacitor on the motherboard that was shorting the -12V to ground. I replaced the tantalum with an electrolytic. The voltage is now steady at -12V but as before, the floppy drive still does not work properly. The disk turns, the red light comes on, and the head can move. But the computer fails to read, or boot from the floppy. I eventually get the famous Abort, Retry, Fail error. I tried to format a disk and I got a "Drive Not Ready" error. At some point during my testing, I did get a "Failure on Int24" error. It seems replacing the cap made no difference.
A component on the floppy drive is probably bad. It wouldn't be a big deal if MFM floppy drives were as abundant as IDE floppies are.
Any ideas are welcome.
Thanks,
-Shawn

You should take a look at the electrolytic caps on the bottom of the fdd. I've found these can sometimes go bad in many of the toshiba t series. They don't always leak but replacing them has repaired a couple of them (including in T3200's)

 

[shawnerz]

Well, it was a valiant attempt. I think I damaged this beyond repair. I only saw a single 4.7uf cap on the bottom of the FDD. I removed it and replaced the SMD type with a radial leaded cap from a capacitor kit I have. I did a temporary solder job just to see if it would work. I didn't see the magnetic (nub) on the "wheel." I powered up the computer, let it boot, put in a disk, and pressed "a:" The nub came around and ripped the cap and the trace from the board. That trace does a "Y" split and one side goes under the "wheel". I do not know what it connects to.
In disassembling the FDD more, I see a couple more electrolytic caps on the other side of the board that were hidden from view. But it's probably a moot point since the trace has been ripped from the board.

Anybody have ideas or a source for older 26 pin, 1.44MB floppy drives?
Thanks in advance,
-Shawn

 

[shawnerz]

You should take a look at the electrolytic caps on the bottom of the fdd. I've found these can sometimes go bad in many of the toshiba t series. They don't always leak but replacing them has repaired a couple of them (including in T3200's)

Thank you for the suggestion about the caps. I bought another broken T-3200 from eBay to use it for the floppy drive. I pulled the drive from the broken computer and put it in the target. The floppy drive did not work. I could tell it was trying harder to read the disk before giving up. But it would fail.
The circuit board in the new floppy drive is a different version. The short version of a long story it the 6V 22uF power supply caps were still good. The polarized 16V 10uF filter caps near the motor driver were both bad. I ordered totally wrong replacement caps from Mouser, installed them thinking they were the correct parts, and the floppy drive is reading disks! Yay!!!
It wasn't until afterwards that i compared before and after pictures and saw I did things totally wrong!
It looks like I'll be ordering some more (correct) parts). 😂
A word of warning though, they are SMT. So you might have break out your SMT skills for these.

After reassembly, this experience, I should be able to recover the other floppy drive.
Thanks again for the suggestion to look at the caps.
-Shawn

 

[kerr]

Hey @shawnerz that's a great find 🤓 it could potentially help fix all the other busted floppy drives from the T3200/SX/T5200 era - a real plague of failed FDDs.

Do you know the model of your drive? And what cap numbers (on the board) were they?

For example, I'm aware of 2 types of FDD in the T5200, a Toshiba ND-356S-A and a Citizen 0SDA-32C.

Cheers!