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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: Lemonty on December 05, 2003, 09:12:56 PM

Title: Diskdrive problem A4000T
Post by: Lemonty on December 05, 2003, 09:12:56 PM
I recently purchased a second-hand A4000T (Amiga Technologies) and encountered this problem:

Using the diskdrive becomes impossible after a few minutes. The drive makes three "gronk" sounds like you get when you insert a faulty disk when in fact there is nothing wrong with the disks.

I've tried replacing the diskdrive with my A1200 internal one to no avail.

I find this problem disturbing and would really appreciate some help. Thanks.
Title: Re: Diskdrive problem A4000T
Post by: Matt_H on December 05, 2003, 09:18:58 PM
Is the drive jumpered correctly? I'm having trouble with a replacement A3000 drive that I think is due to bad jumpers. Check the data and power cables for faults, too.

How does the motherboard/disk module look? Any damage? Make sure there's no battery leakage and lastly, check some other functions of the machine to make sure Paula's not toast (audio, some joystick operations I think).

Oh, and Welcome to Amiga.org!
Title: Re: Diskdrive problem A4000T
Post by: x56h34 on December 05, 2003, 09:19:07 PM
Vesalia sells NOS A4000T disk drive modules, in case yours is busted. Other than that, try using a different floppy cable and see if there are any differences.

I've had a similar problem in my A4000D converted to Mirage 4000 tower, and after trying different cables, the drive worked fine. It turned out that all cables were working fine, but some didn't make proper contact with floppy drive pins. I finally found a cable that "touched" every single pin fine on the floppy drive and viola, it worked! It's really weird. Even after using a spare A1200 drive in A4000 for test the same problems were occuring, so that narrowed down the problem to either the cable, or the motherboard. Luckily it was the cable! :-)
Title: Re: Diskdrive problem A4000T
Post by: DanDude on December 05, 2003, 11:16:06 PM
My 4000T will not read/write floppys with the HD notch snapped off.  If you suspect that a DD floppy works and a HD doesn't, use tape to cover it.   :-)
Title: Re: Diskdrive problem A4000T
Post by: iamaboringperson on December 05, 2003, 11:24:50 PM
The drive is just an IBM-PC type drive. The brand is Panasonic.

Either you should make sure you are tricking it into thinking the disks are double density, or you should align the heads, or you should buy a new one, and throw it in there.

FDD's are cheap these days, so that's the option I would take.

(I have tried -with success - realigning the heads, however it's much easier to buy a new drive!)
Title: Re: Diskdrive problem A4000T
Post by: Castellen on December 06, 2003, 12:24:49 AM
The factory fitted drive in my AT A4000T was a standard PC Sony drive.
The ribbon cable had the centre twist to make it unit 0.  Also the ready and diskchange lines (2 & 34) in the ribbon cable were swapped.

If your faulty drive is the same, then you can plug it into a PC to test it.  Note that a lot of PC drives just won't work in this configuration, so don't expect to chuck any drive in there and get results.

As the others mentioned, you can only ever use double density disks with these drives and the Amiga, even though it works in HD mode the PC.

The ribbon cable is another likely possibility, but I don't think the disks module would cause this problem, unless it was somehow not seated correctly on the motherboard.
Title: Re: Diskdrive problem A4000T
Post by: Lemonty on December 06, 2003, 04:57:09 PM
Problem seems to be solved!

I took out the diskmodule and all the cables, gave them a good cleaning and it seems to work ok now.

Thanks all who contributed! Seems I panicked a little too early.