Short in A4988 / RAMPS board

[andrewm]

Hi,

I"ve just wired up my Acrylic Prusa i3 kit, checked the wiring and then turned it on. Instantly the A4988 on the X-axis started to get very hot (and it burned a hole in the chip), so it would seem that the A4988 or the RAMPS board has a short.

I took the X-axis A4988 off and retested, and it seemed to get hot again (but I turned it off more quickly, so I'm not sure where the problem is).

I've removed the RAMPS board and tested the Arduino Mega with a 9V battery - it seems to be okay (it's still sending text via the serial port, not that I can see what that text is - it's random-looking characters at every BAUD rate). When I put the RAMPS board on the Mega and power it up, the LED on the Mega go out which I assume means that there is a short in the RAMPS board that still needs to be resolved(?).

Do you know where the short is likely to be on the RAMPS board (where I should look for it)?

Thanks,
Andrew

[john]

Hi Andrew,
Could you please give us some photos for you issue? We need more information to help you find out the reason.

[andrewm]

Thanks John.

I found out what the problem was - I had put the X, Y and Z A4988s one pin to the right (and didn't see that under the LCD plug before turning it on). I destroyed two A4988s and possibly the RAMPS board.

I have tested the two remaining A4988s with an Arduino Uno and they work. I have bought and installed a new RAMPS board and installed the working A4988s (and am waiting for spare A4988s to arrive).

Everything looks okay, but I can't get the X or Y axis to move on the new RAMPS board through manual control on Repetier Host (and I could when testing the A4988s with my Arduino Uno). I can sometimes get the Z axis to work, sometimes not.

The only thing that makes sense now is that I've also damaged the Mega board. I've ordered a new one from a local supplier - please send me the firmware so that I can load it on the new Mega. You can send it to printing@supplysignal.org.

[ladlasheikh]

the LED on the Mega go out which I assume...