Not what you want to hear but if you have been over currenting the Gecko you may has blown a mosfet or two.

To be honest I'm not a big fan of Gecko's, I know some people like them but they have given me nothing but trouble on machines that once the driver has been replaced by a decent one, they have run perfectly.

I used to run a big mill on them and they would blow a drive just on switching on in a morning, I spoke to Marriss and he said it was my motors even though I'd changed them and if I plugged another drive in that wasn't as powerful it didn't blow that.
Over a period of time it cost me 10 or 12 drivers.

I ran out of Gecko's and swapped to ARC's large 7.8 amp drive about 4 years ago and no problems since.

What really pissed me off though was about a year ago Marriss was reminiscing on the zone and his statement was :-

" Meanwhile the original G201 was a nasty bear that took over 4 years to subdue; anyone still remember early G201s blowing up for no reason at all on power-up? "

And all the while I was having problems I was told it was my machine.

.