OMG!! My Pololu caught FIRE!!

I did nothing stupid.. when I set it to print it was fine for the first 10mins... Then suddenly SO MUCH smoke came out from one of my Pololu and a second later a flame could be seen, it was as high as 3cm (as far as I could remember)... I was so freaked out and I quickly switched off the PSU power then the fire died soon after that.

Attached photos show the aftermath of the fire, 2 resistors turned charcoal so as a portion at the back of the driver board.

Recently I bought this driver from a seller on eMaker shop, and I'm sure it was a genuine Pololu. However, I was a little suspicious when the seller included a small patch of double sided tape for the heatsink.. I wondered whether the tape was suitable for heatsink or not, whether it would actually dissipate heat or would behave like a blanked to trap heat.. Anyway, I used it as I though it should be OK since it came with the pack.

Although I am not 100% whether it was caused by the tape, but other drivers on my RAMPS which I didn't use any heatsink and they had been working perfectly for months...

Now, I'm scared to power it up again.. is there anything I must check before connecting it???

Sooo, looks like somebody never cleaned the flux off the driver chips?

---

www.Fablicator.com

Thats the heat sink paste, the heat sinks always slide off leaving those pastes trapped at the chip legs.. Whats the best way to clean them btw? Those are almost impossible to clean with cloth or tissue

i wish i could offer you some advice, but i have most of my pololu's from ultimachine, and they have some small heatsinks with there and it is a double sided thermal tape they have with there kits, i have had no major issues with mine from them, unless it is my error, and no that never happens...lol

ill go hide in shame

---

[mike-mack.blogspot.com]

OK, I'm a rookie at electronic solderin, but soldered my Pololu boards onto connectors and mounted on the Ramps board.

I didn't clean any flux off the driver chips. What, where and how do I do this?

I am still wiring stuff so have not powered anything up - yet.

Thanks,

Bob



Andrew Diehl Wrote:
-------------------------------------------------------
> Sooo, looks like somebody never cleaned the flux
> off the driver chips?

my 2 recommendations are distilled water or isopropyl alcohol, and of course give it time to dry and no power during cleaning.

---

[mike-mack.blogspot.com]

Depends on the type of flux. If it's organic (water based) use soapy water and a toothbrush, let dry well. Distilled water is ideal but 99.9% of the time regular tap water will work fine too.

If it's rosin flux, use isopropyl and a toothbrush, and let dry well.

Heat sink compound can be conductive. (and so can organic flux, for that matter) and should never be touching the leads of a chip like that. Clean that stuff off the same way as flux.

You only need a teeny tiny bit of heat-sink compound, and if it's the heat sink tape that is leaving that residue around the chip you should probably find something else (or use smaller tape maybe?)

If it hasn't been said/obvious you need to remove/replace the burned pololu driver before starting things up again. It's 100% toast.

---

www.Fablicator.com