MPM UP2000 6410 Driver Cards Failing

We have an MPM UP2000 stencil printer and have a lot of issues with burned out 6410 driver cards (or driver cards just failing to work). I have looked over these threads and found that this is a common issue with these cards.

I understand that these cards are old and are hard to come by (they are also expensive!). So we don't want to have to keep replacing them when they fail.

My question is - are there any suggestions to a method in which I can modify or add additional circuitry to these boards in order to protect them from destroying themselves?

Things that I have noticed:

Sometimes, the motor output connectors become charred when they fail which indicates possibly too much output current to the motors?

Quite often, one of the slow-blow 15A fuses blows simultaneously to the motor card failure - which supplies DC voltage to the cards in the lower drawer of the UP2000.

The motor current must be set according to the particular axis using the DIP switches on the board. Some of these are 3A, 4A and 5A. For example, for "Squeegee Down", the motor requires a setting of 3A so the DIP switches are set to 3.125A. When jogging this axis in Calibrate mode on the UP2000, I have been measuring currents up to 3.4A - which is outside of the rated drive current for this setting (as specified in the 6410 user manual). Could this be causing the driver card to work too hard and thus burn out?

I have thought of installing additional in-line fuses or a current limiting circuit on the outputs of the driver cards to prevent over-currents but considered that when the printer is in operation, if one of the axes stops working and the computer doesn't recognise this and continues its cycle, could it cause physical damage to the machine itself?

Any thoughts or suggestions would be greatly appreciated.

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