Ramps board doesnt power arduino

So tonight moved machine manually and i think the steppers backfed and blew the fuse for the low volt side. I was able to power it by usb to use it, but i think it needed more as it paused alot while working.

The stepper side still seemed to work ok.

Shooukd i a) replace fuse b) use with a power cord to the arduino or replace the ramps board?

A Ramps board by itself costs only $9 from Amazon and you can get it for less than half that price on Aliexpress. At that price point, I personally would be tempted to just replace the board rather than messing around with fixes or workarounds. If you don’t already have them, the fuses will likely run you a significant portion of $9.

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@RockinRiley Wow, how fast were you moving it?

You don’t need to move them very fast to kill it. Most modern boards are protected from this.

Yea like said just fast enough evidentally. I have them connected in series so that probably does not help. It has always lit the lcd if off. I just need to decide what to do.

You should of course measure the fuse and confirm that it is dead or not. And then u just order a new fuse and replace it! :slight_smile:

There’s also the solder blob bypass trick… most USB ports already have OC protection built in anyways.

I wouldn’t use the 'duino LDO. Those are only good for small fries, and a cnc RAMPs may need more 5V for stuff like relays, TFT’s, etc. I’d bypass the fuse or replace the ramps… or better yet if you can, take a fuse from an old device and slap it on top of the blown one.

I got a chuckle reading your comment about the LCD lighting up. I used to use that as my ‘manual move speedometer’. “We’re just looking for a low glow here, if you start seeing characters you’re pushing it too fast.”


It’s also possible you blew a voltage regulator rather than a fuse. I’ve replaced them (unsoldered/resoldered) in the past, but at this point the part ala-carte with shipping ends up being more expensive than a whole new ramps setup.

If your display only lights up when the Arduino is powered by USB, that’s a symptom that the 5v regulator got fried. I used my 3D printer powered through both USB (for logic power) and 12V power supply (for motors and heaters) for a couple of weeks with no problem while waiting for parts to come in. During this period I used Repetier Host to start jobs, I didn’t print from SD cards.


Lol, wish i had read that long ago :wink:

To kill it, you don’t have to move them very quickly. Modern boards are generally shielded from this.

So the voltage regulator is on my arduino, not my ramps board. I have just bought the wrong thing, dang it.

Looks like more work this afternoon.