Steppers loud with replacement a4988 drivers?

Hey folks,

One of my stepper motor drivers died so I bought a new set. I decided to replace them all at once. After adjusting the pots and ensuring that Vref was 0.4V or lower, I started printing a test cube. Unfortunately, the motors are now extremely loud for the X and Y axis! I can even see the belts vibrating. I swapped back the X and Y drivers back to the old a4988 drivers and the loud vibrations went away. Did I buy a bad set of drivers, or do I need to do something different with the new driver boards? The layout is slightly different compared to the old ones I had, but they are indeed a4988 chips and not the new drv8825 ones.

Thanks for any help,

Paul

The Vref of your old drivers might not work for the new ones. Check if the new ones have the same shunt resistors. They can vary between 0.200 and 0.05 ohms ( reads R200, R100 or R050 )

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o_lampe
The Vref of your old drivers might not work for the new ones. Check if the new ones have the same shunt resistors. They can vary between 0.200 and 0.05 ohms ( reads R200, R100 or R050 )

You're right. There are two R100 resistors next to the S1X and S2X labels on the board. That said, I tried a wide range of Vref values and still have the issue of noise :\.