Bad stepper driver

[Mmmsabeel]

hello,

my stepper motor wont turn smooth, its very rough. it has a big vibration and makes noise. this problem i found in the stepper driver. i connect this stepper driver to any of the motors this happens. please someone advice me on what i have to do to get this fixed. do i have to replace with a new stepper driver ? or is there any settings that needs to be done on the A4988 driver ? pls check this video i have uploaded.
https://www.youtube.com/watch?v=wjCW6u-8Epw

if the video is not clear please check the similar issue.
https://www.youtube.com/watch?v=fVnEB7JLRK8

https://www.youtube.com/watch?v=sk2yA7tWsjQ

and before this problem occur i had this issue,please check below video. only to one direction bed moved. i removed the driver and put it back solved the one direction movement and started giving this vibration and not moving properly problem.

https://www.youtube.com/watch?v=GwuoOiJDTvk

Any help would be gratefully appreciated
Best Regards
Sabeel

[zhangxueyou]

1. When you connect this stepper driver to any other motors, the same problem happens. Yes, we can conclude that stepper driver is broken. You have to replace with a new one. The GND of stepper driver must be connected to GND of mainboard, you can see "GND" both on stepper driver and board. Please contact the customer service.
2. From the video you post, when you move z axis, you set the value at 150 mm. The motor won't stop until it moves 150mm,even you set the value at 80 when it's moving. So when it reaches top, of course it jitters.

[Mmmsabeel]

thank you for your reply, so today i have bought a driver from ebay. so how can i contact customer support ? on the website contact us i added the skype contact but they dont reply. why do i have to contact them ? will i get a free driver ?

Regards
sabeel

[zhangxueyou]

Please tell me your purchase link, and you order number.

[Mmmsabeel]

my order link is http://www.ebay.com/itm/251858841851?_t ... EBIDX%3AIT

[zhangxueyou]

We have informed customer service, they wil process it as soon as possible.