Reasons why my external 1200 floppy port doesn't work

[bubba]

I have a towered 1200 with a 1B motherboard.  The internal floppy works fine.  A floppy drive connected to the external port never is recognized.  The same drive works fine on another 1200.

Anyone know what might be wrong and if there is an easy fix?  Also, is there anyway to use the internal connector to connect a second floppy instead of using the external port?

Thanks,
Bubba

[ajlwalker]

One of your CIA chips may be faulty.

They are notoriously fragile.  I think they may be some of the few chips on an A1200 that aren't surface mounted precisely for this reason.

Someone will be along to confirm or (probably!) criticise what I say.

It may be possible therefore to swap out CIAs from a known working A1200 and see if this sorts the problem.

As an aside it is essential to not plug in or remove any peripheral (even a mouse or joystick) whilst the machine is on.  That way you will get the best life out these chips.

Edit to add:  I've just checked some photos of various A1200 motherboards and it looks like the CIA chips are NOT socketed to it will be a tougher repair if this is indeed the fault.  :-(