A4000D not recognizing floppy

UberFreak

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Hi

I'm currently rebuilding an A4000D from bits & pieces I got.
Its an 030/25Mhz unit, all capacitors in the PSU & motherboard have been replaced.

It boots fine from HDD, but wont boot from floppy (I do see the drive light up & do a short spin).
On the desktop, it shows as "DF0: ???" no matter if there's a disk in or not.
There is also no "click" sounds from the drive, at all.

I thought the drive is at fault but it behaves the same with another drive which works in my A1200.
Also tried a different floppy cable, same results.

Am I looking at a bad floppy controller? :help:
Any ideas would be greatly appreciated!
 
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Bootay

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What a coincidence, this just happened to me when I took mine apart and put it back together. The problem for me ended up being that the cable bent some of the pins and some of the pins are either touching or not lined up in the plug correctly. I know it is not flipped the wrong way because the activity light would stay on and it would not even acknowledge a floppy in the drive. So you have the cable correct but check the pins.

Other than that...I could not tell you if a bad controller would cause this.
 

protek

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The floppy drive in my A1200 also acted weird, when I disassembled and reassembled it. Turned out that the cable was at fault. I think you might want to give a new floppy cable a shot.

Edit: Sorry, it seems you already tried that.
 

jvdbossc

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noclick

noclick

Just adding to the list of suggestions..

I would first check if it clicks in the rom screen by disabling the hard disk.

If it doesn't I would guess bad floppy drive, or as suggested faulty cable. You can build from a pc floppy drive a perfect DD drive, can post instructions.

(however it is alover the net, so you might just an already "almost" compatible one)

If it clicks in the rom screen, then noclick is installed in workbench probably, and I would clean the heads of the floppy drive with alcohol.
 

UberFreak

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Thanx for all the suggestions!

@jvdbossc:

There are no clicks even without the HDD, tried two drives & two different cables.
I just verified both drives work fine in my A1200, so it looks more & more like a motherboard issue :(

Are there any jumpers on the board that can cause this behavior?
As far as I can tell, the board works perfectly in all other aspects.
 

jvdbossc

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oops

oops

Can't help you further don't think there will be any jumpers on the motherboard. The A4000 is also kind of new to me, but on other amiga's they are all on the flops themselves..

Quite sure some more advanced user will pick up this thread ;)

Can't think of any other obvious other reason :blink:

Well of course you suggested already one (n) :Doh:

Anyone ??
 

Kin Hell

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You could have a blown CIA chip. They are to the rear of the board next to the PSU. If they are surface mounted, it would require someone with competent desoldering & soldering skilz. If they are socketed, it's just a case of flipping the old ones out & installing the new ones. For the life in me, I can't remember which one is responsible for addressing the Floppy. :shrug:

The chips are marked CIA ODD and CIA EVEN.

Kin
 

UberFreak

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@Kin:

Is one of the CIAs responsible only for the floppy?
I'm hoping there are other symptoms I can check for, to verify if the problem is indeed CIA related.
 

protek

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@Kin:

Is one of the CIAs responsible only for the floppy?
I'm hoping there are other symptoms I can check for, to verify if the problem is indeed CIA related.

If the CIAs are socketed, you can easily test them by swapping them with each other. If one of the CIAs is faulty and you swap them, then something else will stop working and your floppy disk drive should start to click.

Edit: Based on bboah.com, it seems that both B and C revisions of the A4000 mobo have soldered CIAs.
 

UberFreak

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Yes, unfortunately the CIAs are not socketed & they are also the PLCC type, for which I have no spares or tools to remove them.

Is there a diagnostic software that can test the CIAs?
I remember having something like this for the C64 so maybe there's something similar for the Amiga.
 

rkauer

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Floppy functions are controlled by Paula with little or no help at all from CIA.

There are two floppy jumpers in A4000D:

J351 ON: No second internal floppy or second internal floppy is 1.76MB

OFF: Enabled second 880K floppy as DF1: Redirect DF0:

J352 1-2 Internal DF1: and DF0:, External DF2: and DF3:

2-3 Internal DF1: and DF2:, External DF0: and DF3:


Notice that you can hook an external drive and move J352 to position 2-3 to use the external unit as DF0: . This will also test if you have a major hardware problem on Paula or whatever.

The DF0: ???? icon problem is well known and is caused by a stuck insertion sensor switch. Open the unit and drop WD40 or IPA ( = isopropyl alcohol = isopropanol) in the switch an click it for some time (30 clicks will suffice). The switch is sided by the write protection sensor one.

Also test it with another non-pc cable, or use only the non-twisted part of it.
 

UberFreak

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Thanx, I'll recheck the jumper settings on my board.

I currently dont have an external drive, but I know someone who has so this will be a good thing to check!

The drive in question (with its cable) works perfectly in my A1200, so I ruled this out as a problem.
Wish it was though, replacing a drive is much easier than debugging the A4000 board :LOL:

---------- Post added at 15:43 ---------- Previous post was at 14:58 ----------

@rkauer:

According to info at zimmers.net:

J351:
Open - no DF1 or High Density DF1
Closed - Low Density DF1

---------- Post added at 15:56 ---------- Previous post was at 15:43 ----------

Just found a thread on amiga.org, describing the exact same problem as I have.
That guy also replaced CIAs & tried an external drive, with no success.

Thread is more than 2 years old, wonder if he managed to solve the problem...
 

rkauer

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OK, A4000D's manual (both web German one and mine USA version) says the same as Zimmers:

J351 OPEN = OFF : no second drive or it is high-density
Closed = ON : second drive is DD.
 

UberFreak

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OK, now I'm REALLY confused!
You wont believe what just happened :eek:

Just for kicks, I tried connecting a 1.44MB PC floppy drive, and IT WORKS.
It boots & WorkBench sees it & it reads Amiga disks!

Can someone explain this?
An A4000 that works with PC drives but not Amiga drives?!? :huh:
The most bizarre thing is, this unit originally came with a Chinon High-Density drive!

---------- Post added at 16:34 ---------- Previous post was at 16:26 ----------

Correction:

When I booted WB from the PC floppy drive, it looked ok (DF0: worked from WB).
When I boot into WB3.0 from HDD with this floppy connected, it still appears as "DF0: ???" but now there's also a "DF1: ???"

WEIRD!
 

Kin Hell

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@Kin:

Is one of the CIAs responsible only for the floppy?
I'm hoping there are other symptoms I can check for, to verify if the problem is indeed CIA related.

Yes, one of them is. The CIA's pretty much control all the input/output devices on your Amiga. As mentioned ealier, just about all A4KD's shipped with surface mounted CIA's. I mentioned the socket scenario just in case your board might have been re-worked in the past.

Good luck.

@ rkauer

As I mentioned earlier, one of the CIA chips does have some control over the floppy. CIA's do have some control over all input/output ports on all Amiga models.

Kin
 
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protek

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@ UF: The PC drives are by default ID'd as #1 and not #0 as in Amiga, hence the DF1:. Did you try format a disk? Can you get it formatted as 1.76 MB? The A4000 shipped with HD drive by default.
 

UberFreak

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Problem solved :)

It was mostly bad luck followed by more bad luck :(
The HD floppy is dead. When I tried it with my A1200 yesterday, I didnt try to boot anything, I was just happy to hear the clicks, as it didnt click with the A4000.
An hour ago, after seeing the PC drive work, I decided to check the Chinon properly with the A1200.
This time, it didnt click, just stone dead.

Then I took a spare A1200 drive I also checked with the A4000 yesterday (it didnt work) and I tried it with the A1200 as well.
Surprise, it also didnt work!

Now I was pissed, opened my A2000 & took its drive to the A1200. This time, all went well & the drive worked.
I then tried it with the A4000, and... it worked! :)

Looks like all the drives I tried were bad! :mad:
 

rkauer

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Floppy units from PC world will work at first glance, but they'll bring some issues regarding disk swapping and the ready signal.

PC world units don't have those signals.

Also they are set to DS1 instead DS0 as the Amiga requires.
 

protek

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Your best option would be to try to find a new Chinon FB-357 or FZ-357, depending which one you have, if you want to have the 1,76 MB supported. Most of the other options like modified Panasonic drives will give you only 880 kB support.
 
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