A4988 failed after 5hrs of use

Hi,
Ive had one of these fail after about 5 hours of use, if i swap the board out for another it works fine, the pot is set on 1/3 of a turn.
Have checked solder joints and all look fine under a microscope, it gets slightly warm from usb voltage (via arduino & RAMPS) and thats all it does.
The three other are working fine, I have a fan cooling them and are only slightly warm to the touch while in use.
I contacted the seller and he said these burn up very easy and that’s why they are replaceable units and i should purchase another.
But I cant afford to keep replacing these if they only last a short time.
My board looks slightly different from the one in your picture, can you tell if these are genuine cgi.ebay.co.uk/ws/eBayISAPI.dll? … 500wt_1261
Setup:
4 x A4988
SY42STH47-1684B High Torque hybrid stepper motor zappautomation.co.uk/product … bc6b8dae2e
RAMPS V1.2 reprap.org/wiki/RAMPS_1.2
Arduino mega 2560 arduino.cc/en/Main/ArduinoBoardMega2560
ATX psu for 12v

Thanks for your help.

Hello.

We cannot vouch for things you see on eBay. Our official distributors are listed on our distributors page, and I am not aware of any counterfeit issues with any of them.

I think the “burn up very easy” comment depends on your perspective. Used correctly, they should last a long time, and I think they would not be in such widespread use if there were some fundamental quality or reliability issues. On the other hand, you are working with bare electronics, so it is easy to destroy them. Static discharges, unplugging powered motors, and voltage spikes (on either supply) are among the things that might happen inadvertently and which might not instantly kill your device but which can have a cumulative effect.

- Jan

Thanks for your reply.
Its reassuring to know there are many in use without issue.
I think I will get a replacement from one of your distributors as suggested and see how that goes or maybe build one from scratch. (using BGA equipment)
I’m guessing it was a faulty a4988 as the other 3 are ok and they was all built using the same ESD precautions and have the same power supply’s.
Cheers