mesa 5i25 card problem

Not sure if this is the right place to ask this but I will anyway

I have a Mesa card 5i25 which has been running well for about 12 months now, I don't think it is still under warranty, but it may have developed a fault which I don't know what to do about.

it is driving a Gecko g540 and I'm using Linuxcnc v2.8.1.

The problem that has just started (after I reinstalled a new hard drive and copied everything back onto it) is that when I activate linuxcnc and press the machine on button to activate everything it does that but then it randomly switches itself off again within a few seconds to a few minutes.

I have re written the 5i25 with the command sudo mesaflash --device 5i25 --write 5i25_g540x2.bit, which it does successfully and also verified it successfully.

I have unplugged the db25 cable from the 5i25 and ran everything from my original software using the parallel port and that works without a problem (the motherboard is not great and I do get timing issues which is why I prefer the 5i25) however it does not randomly turn of the machine.

I am not sure if the board has developed a fault or if I have done something incorrectly. I would appreciate any assistance in this matter before I replace the board. I have also sent a copy of this to Mesanet but I think I would get better support from this forum
Eric

thanks tommylight, but I get no warning of any kind and a screenshot would show only the axis screen, I can fire up linuxcnc no problem, I turn on the machine-is-on button (F2) all other buttons etc become active, then I do nothing else, no homing, no motion, nothing and the f2 button just goes false. I have looked for noise on the estop line as well as the machine-is-on and machine-s-enabled but they only show high or low,
Mesa tech suggested I clean the contacts and check the jumpers etc, but that just means they have no idea either. it may be noise, but with nothing on that is electrical around, not even the lights, I have no idea where to look.
I don't want to buy another card only to find it was something simple and not hardware, hence why I'm asking here.
Eric

Which inputs do you have on the Mesa card that can turn the machine off? If you identify those, you could try moving them to other inputs on the Mesa card. That would exclude any hardware errors on specific inputs, as well as constitute a contact cleaning/good connectivity check.

good thought, thanks, I'll look into that tomorrow (8:15pm here and too cold out in the shed)
Eric

it appears to be all good now, I cannot believe how it was fixed, I tried everything I could think of and finally tried unplugging the stepper motors and the interface stopped flicking off, waited ages but it did not happen, so I plugged each stepper back in one at a time waiting ages between each one and I ended up with all three plugged back in and it appears to be stable again???
dirty plugs and sockets?? I have no idea
Eric

If a connection between a driver and a motor is intermittent that could lead to high voltage inductive spikes, which could cause permanent damage or temporary "lock-ups". The spike might arc and cause both direct injection of high voltage and strong EMI that could disturb logic level parts. So maybe that's an explanation?