Hi.
I have build myself a prusa i3.
Somehow my X stepper driver keeps dying on me.
It’s an a4988 chip.
Sometimes it works for hours, sometimes a few minutes.
This morning I had a print that had shifted aprox 10mm on x, but it still worked.
So I stopped the print and started it again after cleanup.
Then the driver crashed again.
I tried resetting my arduino with no results.
Anyone with a good advice what’s wrong?
Drill the stepper cables.
Test with sd-card if possible.
Use heatsink and a extra fan for your a4988
Drill The cables? Explain please?
I only print from sd.
Will try putting on cooling on The drivers.
In german we say “verdrillen”.
http://reprap.org/wiki/RepRapPro_Mendel_wiring/de#Wichtig:_Generelle_Regeln_f.C3.BCr_die_Verkabelung
Look at picture Kabelführung.
Check the Vref, should be around .4v
Ach so. 
Twist The cables you mean?!
Won’t be easy because I’m using telephone cable which is flat 4wire.
Could that introduce some nasty cross talk maybe?
Wayne, will check that later when the kids are sleeping again.
Sounds more like a bad connection somewhere. Check the wires and connectors, (preferably with a continuity tester while wiggling them around). If you can’t find an error in the wiring, swap the driver board with a different one (e.g. X and Y) and see if the problem persists or now affects the other axis.
The driver chip’s temperature should be cool enough to touch it. It will be warm or even hot, but shouldn’t burn you. If it does, reduce the drive current with the potentiometer. There are different driver designs out there, so tuning by reference voltage can give you some very erratic results.
Also check that your axis is moving smoothly, that is all the bearings running without spots where they bind and the belts not rubbing anywhere.