Anet A8 auto Home not working

[TheSingularity]

I am using the most recent version of marlin, which I installed onto my Anet A8 printer. For some reason the auto home is no longer working on the Z axis. When I use the auto home function the printer homes the X and Y axis, then the Z moves up but not come back down. I have reinstalled Marlin (the same version as the one I had installed before) and still the problem persists. This is not an error with the firmware as the printer was working fine even after the first installation of marlin. I have also tried just unplugging the Z axis home switch, which did not work either.
Please give me any suggestions. Thank you.

[Roberts_Clif]

When flashing new firmware you need to send code to read the firmware and store the firmware configuration into memory.

To do this send
M502 - Factory Reset
// If you need a different Z-Offset you can enter it here
// M851 - XYZ Probe Offset
M500 - Save Settings
I do this from Cura 15.04.6 in terminal mode

This can also be done from LCD
Load Settings
// If you need a different Z-Offset you can enter it here
// M851 - XYZ Probe Offset
Store Settings

[wbucket]

I am using the most recent version of marlin, which I installed onto my Anet A8 printer. For some reason the auto home is no longer working on the Z axis. When I use the auto home function the printer homes the X and Y axis, then the Z moves up but not come back down. I have reinstalled Marlin (the same version as the one I had installed before) and still the problem persists. This is not an error with the firmware as the printer was working fine even after the first installation of marlin. I have also tried just unplugging the Z axis home switch, which did not work either.
Please give me any suggestions. Thank you.

Hi, I recently had the same problem. I searched the net and your post is the only one that describe what i am facing. Did you solve your issue?

[curious aardvark]

the bit that confuses me is the z-axis going up to home.
Mine homes at the bottom of the gantry travel.

Could it be that you have 'home to z max' or z+ configured in the firmware and not home to 'z min' or 'z-'
It's definitely going the wrong way to home.

[wbucket]

the bit that confuses me is the z-axis going up to home.
Mine homes at the bottom of the gantry travel.

Could it be that you have 'home to z max' or z+ configured in the firmware and not home to 'z min' or 'z-'
It's definitely going the wrong way to home.

Strange thing is everything was working fine. I used it for 2 years.
Then suddenly this happened.

I uploaded a short clip of the autohome for reference.
https://www.youtube.com/watch?v=eMk9rw-ZGfA

[wbucket]

Hi, I did a quick check and found out through serial commands that Z limit is always triggered. Search net n found similar cases and solution involved doing some reflow fix for the component on board. Decided instead that it is time to upgrade my board.