I'm not 100% sure about this but I seem to remember the ROMs in my
A1200 being 2 pins less than the socket provided for them.
They may need to be seated to the furthest pins on the right.
Don't go by this though, double check - especially since this could
apply from the front or reverse (depending on how you are looking at
the motherboard).
Another thing that is worth keeping in mind is that there's 2 ROMs (at
least on A1200) and they have to be put in their own socket. I
couldn't tell which was which - so I never tampered with mine.
This was a problem for me too, as was the IDE interface which wasn't
clearly labelled at all.
Usually there are ridges on cables etc. to stop you inserting them in
the wrong way.
