Floppy drive problem

[AlfaRomeo]

I have a towered A1200 mounted from a mobo where the floppy drive doesn´t work. I don´t know if ever worked because I took the mobo from a broken A1200.
I tried 4 drives that I know are good and none worked (when connect power they start and stop motor only) however I didn´t note any other issues in the mobo (parallel port works but didn´t tried serial).
What could cause that?

[cpiac64]

the 4 drives are for pc?
if yes then change ds1 to ds0 - dc to rdy and more

p.s.
your sam440 mount os4.1.1?

[prowler]

Hi Alfa,

cpiac is right. If you are using a PC floppy drive, you will need to set the unit as DS0 instead of DS1, route the Pin 34 trace to Pin 2 and remove it from Pin 34 and put a link between Pins 30 and 34. This will convert it to work properly with your Amiga.

Note that this will not work for two or more floppy drives.

[AlfaRomeo]

The floppy drives are all from Amiga (A600,Commodore A1200 and Escom 1200) but I also tested a PC drive with the floppy mod from Stedy and none worked

Originally Posted by cpiac64

your sam440 mount os4.1.1?

No I have OS4.1

[AlfaRomeo]

I tried to force some programs (PC-task, Directory Opus 4) accessing the floppy drive but everyone that try to access the floppy crash (without any guru) and I can´t even close it, but OS keeps running ok.

I think that may there is one signal faulting to the drive, it´s this possible without notice any other issues in the computer? What could be the chip responsible for that?

[cpiac64]

are sure for connection, have respected signal 1 wire red on board and on floppy

[AlfaRomeo]

Originally Posted by cpiac64

are sure for connection, have respected signal 1 wire red on board and on floppy

I´m sure, it´s all well connected. I have another A1200 where I tried all that drives in it all works ok.
So, my guess is that one or more electronic signals to the drive are lost.

[cpiac64]

change cable 34 pin and verify power 5v and 12v with tester

[AlfaRomeo]

Originally Posted by cpiac64

change cable 34 pin and verify power 5v and 12v with tester

Done that already.
My question is: As, normally, the Amiga internal chips control more than one thing at a time, it´s possible that there is a faulty chip that only it´s visible through a malfunction in floppy drive without any other issues in the computer?

[cpiac64]

dowload a schematics and verify with teser if all capacitors 100 n F are in fault (zero ohm)

[rkauer]

Originally Posted by AlfaRomeo

Done that already.
My question is: As, normally, the Amiga internal chips control more than one thing at a time, it´s possible that there is a faulty chip that only it´s visible through a malfunction in floppy drive without any other issues in the computer?

All of floppy hard work is done by Paula. One of the CIA is responsible by only a few control signals.