Anet A8 auto Home not working

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.

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

Quote:

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Originally Posted by 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.

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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?

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.

Quote:

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Originally Posted by 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.

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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

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.