Wow... 4 x Pololu burned up instantly on Sanguinolou!

Well I don't know how I did it, but the moment I connected the power to my brand new Sanguinolou, sparks and smoke shot out of my 4 x Pololu's.

I had nothing but power connected, no steppers, no tip/bed/endstops/thermistors/usb etc

I'm not particularly a novice, I've got a prusa and a couple of orcas and built my own ramps etc but this was a complete board ordered off the internet. I plugged in my PSU and wow, it was like opening night of the olympics.

I've used the PSU before. Its a 12V 40A, very stable, I definately observed the correct polarity. I'm guessing there's a short on the board or something. I've heard of people burning up single Pololu's by passing too much current, but something must have seriously gone wrong to kill 4 at once?

Anyone got any ideas on what it might be? I want to test it, but I dont want to break any more components!

Think I worked out what happened, currently on the VREG I've got 12.2v going in, 11.8v coming out. Guess that means a faulty Vreg or it's had the polarity reversed before getting to me.


Just my luck ... is this board a write off?

Most likely the micro controller is also toast, and the USB chip. So if you are resurrecting the board, make sure you have the Vreg checked before placing those parts.

12V where there should be 5V will kill the ATmega, the drivers, and possibly the FTDI chip. Ask me how I know

All the other components should be fine (not that there are very many).

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Lol go on, how do you know, did you have an impromptu fireworks display too? Thanks for the advice guys. I'm gonna replace the cheap stuff and keep this as a spare if I can get it going. I'm much more sold on the ramps these days

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I'm much more sold on the ramps these days

Good luck. RAMPS isn't more expensive because it's better quality, but because it's more complex. Spending more money usually gives a better feeling, that's right.

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Generation 7 Electronics	Teacup Firmware	RepRap DIY

Traumflug Wrote:
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> I'm much more sold on the ramps these days
>
> Good luck. RAMPS isn't more expensive because it's
> better quality, but because it's more complex.
> Spending more money usually gives a better
> feeling, that's right.

I'm planning on doing experimentation with multiple extruders, which is one reason I use RAMPS on my machine. If Gen7 had support for five stepper drivers I would gladly try it. I usually use a Sanguinololu on printers that I plan to sell. Do the 644 or 1284P have enough pins to support an additional stepper driver?

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Do the 644 or 1284P have enough pins to support an additional stepper driver?

Yes, and the extension board connector has all the pins to connect such an additional extruder. There's just somebody needed, brave enough to copy a thermistor input, a heater output and a Pololu header onto such an extension board. I'd even make a free board for this hero.

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Generation 7 Electronics	Teacup Firmware	RepRap DIY

I'm thinking Gen7 will probably be the next set of electronics I buy. I am an engineer, but not in electronics. I've been meaning to learn PCB creation software for some time now, maybe this will give me the motivation to do so.

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