I purchased an Anet A8 about a month ago and assembled it about 3 weeks ago. I've had several successful prints with it, but one problem that has become increasingly problematic with time.
A couple of weeks ago, I noticed that after a print ended I wouldn't be able to home the z-axis. Instead of travelling down to the endstop and then jogging up a bit, it would just jog up a bit and stop. If I navigated through the LCD menu to check the status of the endstop it would say "on" even when it wasn't engaged. The only way I could "reset" the system was to unplug it for a while and try again. It tended to home properly when it was freshly turned on and it tended to not home properly when it had been on for a few hours.
Recently, I ran into the situation where I can't get the z-axis to home even if it's been off overnight. Using the touchpad, I can only get it to travel up, not down, and the endstop reads as "on" even when it isn't on.
Here are some things I've already tried (with results in parentheses):
--Test limit switch with multimeter (The switch functions as it should.)
--Test limit switch cable (I also found no shorts in the cable)
--Unplug limit switch (the status stays "on" even when the limit switch is unplugged)
My suspicion is that something is wrong with the mainboard itself, but before spending the money (and waiting for one to ship), I wanted to see if any of you had any ideas of other things I could test/try.
For your reference, it's essentially a stock Anet A8. The only mod I've done is to run the power to the heated printbed through an external mosfet. The z-axis problem I've described above was happening before I added the mosfet and has continued with the mosfet in place.
Thanks in advance for any ideas you have!
