TEAC FD-235F immediately try to read disks also if it's empty

[Omolungo]

Hi everyone, here I am with a new issue.

The drive is as the topic says, a TEAC FD-235F drive originally mounted in a Commodore A500 rev. 5.

When I power on the Amiga the disk drive immediately spin trying to read the floppy disk, also if any disk is inserted: the heads just give two "reading attempts" if you know what i mean, then stop to spin.

If I power on the Amiga with a floppy disk inserted the drive starts immediately to read the disk, correctly and fine, but if I have to change a disk the problem come back since if I'm not fast in changing the disk, after a couple of reading attempts it stops again to read.

It is normal, but the problem I think should be in the sensor for the presence of a disk, which is always active even if a disk is not inserted.

I tried the disk drive in different Amiga 500 motherboards but the issue is always the same, so the problem is on the disk drive itself.

What do you suggest to do?

[Omolungo]

This is the drive

[solarmon]

Inspect and clean and lubricate (with a cotton bud and WD40) the disk presence switch in the floppy drive.

Use Amiga Test Kit to check the floppy disk drive signals are all OK

[Omolungo]

Already done.

Lubricated the switch but nothing changed.

The signals using Amiga Test seems to be all ok (I used an old version, when it was still called SysTest)

[solarmon]

Can you show your jumper settings on your TEAC drive. I have the same model and my jumpers are like this:

[solarmon]

Originally Posted by Omolungo

Already done.

Lubricated the switch but nothing changed.

The signals using Amiga Test seems to be all ok (I used an old version, when it was still called SysTest)

In SysTest do you see the 'CHG' signal appear when you insert/eject a floppy disk?

[Omolungo]

Originally Posted by solarmon

In SysTest do you see the 'CHG' signal appear when you insert/eject a floppy disk?

I'll try to check

[Omolungo]

Originally Posted by solarmon

Can you show your jumper settings on your TEAC drive. I have the same model and my jumpers are like this:

It is like mine.

the switch of disk presence seems visually alright

[solarmon]

Originally Posted by Omolungo

the switch of disk presence seems visually alright

Use a multimeter to check continuity when the Disk Presence switch is pressed down. But Amiga Test Kit / SysTest will also show the CHG signal.

[Omolungo]

With signal test I have 0 Index Pulses.
If I take off the floppy disk I have no CHG signal

Sometimes I have 1 CHG signal when I take off the floppy for the first time, while with another drive working normally I have CHG signal every time

[solarmon]

The INDEX pulses will only appear when the MTR signal is turned on for the drive.

Also the CHG signal only resets when you do a STEPing. But since you said that it did change at least once suggests that it does work.

I suggest you get the latest version of Amiga Tesk Kit that has more floppy drive testing functions/features.

[Omolungo]

Tried with last version of Amiga Test kit and partually fixed the problem: infact if I gave signal test to the drive and I reset the Amiga it starts with the classic tac, tac of the floppy searching for a disk.
If I insert a disk it starts to read it nomally, if I reset the machine it start again correctly.

After a pair of attempts anyway the problem come back (or if I use a game in which there's to change the floppy, i.e. Defender of the Crown).

If I use again signal test in Amiga Test Kit the drive start again to work normally.

Maybe a problem with some capacitor?

[solarmon]

Here is a good source about the Amiga floppy signals:

http://www.primrosebank.net/computer...orage_fdis.htm

I don't know whether an issue with the Disk Change signal could be related to caps, but the drive does have caps and I suppose it is an easy thing to try to rule them out.

Have you tested another known working floppy drive to try in this Amiga 500 - to rule out any issues with this Amiga 500?

[darefail]

Just a stupid question.. Are you sure that the floppy cable is placed correct? Pin 1 on pin 1.. You know..

[solarmon]

Originally Posted by darefail

Just a stupid question.. Are you sure that the floppy cable is placed correct? Pin 1 on pin 1.. You know..

I do not think that this is the issue here - as it has been reported that the issue is intermittent. If it was plugged in wrong then it wouldn't work at all. (EDIT: Assuming a normal floppy data ribbon cable and connector is used, and not individual Dupont cables!)

EDIT: In one of the pictures you can see a ribbon cable and connector is used. Although the end of the ribbon cable with the red stripe is not on pin 1, this does not matter if the other end is the same orientation - as long as pin 1 is going to pin 1, etc.

EDIT: In an A500 you typically find the floppy cable orientated this way - the red stripe is not on pin 1. This is to allow the metal shielding to fit properly.

[Omolungo]

Originally Posted by solarmon

Here is a good source about the Amiga floppy signals:

http://www.primrosebank.net/computer...orage_fdis.htm

I don't know whether an issue with the Disk Change signal could be related to caps, but the drive does have caps and I suppose it is an easy thing to try to rule them out.

Have you tested another known working floppy drive to try in this Amiga 500 - to rule out any issues with this Amiga 500?

Thank you for the link

Yes, I tested another known working floppy to this A500 motherboard, but maybe not so deeply; I also tested the Teac drive in another mobo.

I need to perform other tests anyway.

[Omolungo]

Originally Posted by darefail

Just a stupid question.. Are you sure that the floppy cable is placed correct? Pin 1 on pin 1.. You know..

I tried in both sides, since the red wire was opposite compared to other disk drive, but I found other images of rev. 5 motherboard with the cable put in the same position. Any issue about this

[Omolungo]

Originally Posted by solarmon

EDIT: In one of the pictures you can see a ribbon cable and connector is used. Although the end of the ribbon cable with the red stripe is not on pin 1, this does not matter if the other end is the same orientation - as long as pin 1 is going to pin 1, etc.

Exactly

[Methanoid]

Originally Posted by solarmon

Inspect and clean and lubricate (with a cotton bud and WD40) the disk presence switch in the floppy drive.

Use Amiga Test Kit to check the floppy disk drive signals are all OK

is that Keir Frasers disk or something else (if latter can U link me). Mine is also being difficult

[solarmon]

Yes it is Amiga Test Kit (formerly SysTest) by Keir Fraser:

https://github.com/keirf/Amiga-Stuff