@BaronSFel001, Hi and welcome to vogons!

Assuming your case is obviously long enough to cater for the length of the LAPC-I, normally if the card is not fully inserted on one side it means that your motherboard is not seated properly and is slightly bowed. With some older cases there is several plastic standoffs that lock the motherboard into the case. Check to see if 1 or more of these plastic standoffs are correctly inserted. Also if you have a combination of motherboard screws and plastic standoffs, check to see if the motherboard screws are not pushing the motherboard down slightly further than the standoffs as this will also cause the motherboard to bow. Usually the 2 screws on the left hand side. This is assuming you have plastic standoffs holding the motherboard down of course.

If all the above is fine, then bend the bottom of the LAPC-I slot plate slightly before inserting the card into the slot as sometimes this is all it takes to seat the card that further few millimetres into the slot.

Hope this all makes sense 😀

Yes, that made sense, thanks. Actually, the motherboard seems fine but I think your answer helped find the cause: the metal notch at the bottom end of the external connectors on the LAPC-I appears not to fit between the motherboard and the case. I compared it to my AWE64 that inserts fine and the notch on the AWE64 is definitely thinner. At this point I wonder if a little work with pliers may do the trick.

Keep in mind that this forum is for Windows games. For old hardware, ask in Marvin.

Sometimes in some computer cases you will have to get a pair of pliers and grip the little "tooth" on the bottom end of the metal bracket on some cards and give it a very minor / small bend one way or the other to get in some cases. I've had to do this several times to get cards to fit. If you're careful it shouldn't damage the card, but you can usually take the metal bracket off and do it then put it back on if you're worried. This may help your situation, maybe?