Sonarmote - smoked!

[pyndot]

Hi All, not the greatest way to introduce myself to this community but I need to none-the-less...

I have been playing around with the SonarMote R2 and it has been working well for quite a few days. But this morning I was playing with the power supply options to the unit and accidentally sent over-voltage to the LiPo battery terminal. If you see the attached pic smoke emanated from the red circled area and the HC-SR04 unit now has no power... The rest of the unit works fine.

So I was just wondering what the two circled components are and if I can replace them? I assume they are the voltage boost component to get 5v to the sonar sensor?

Update - I think it is the 6 pin component I fried which is a Noninverting Buffer / CMOS Logic Level Shifter taking 3.3V logic from Motion pin D5 and converting to 5V supply for sensor... This looks difficult to replace! 

[Felix]

It's a LTC 3525 5v booster.
If you haven't done SMD before it will look difficult but probably feel easy with a good soldering iron and some flux.

[pyndot]

Ahh OK. I can certainly give it a try but I will have to remove the headers around it first for access!

Thanks Felix!

[TomWS]

It's a LTC 3525 5v booster.
If you haven't done SMD before it will look difficult but probably feel easy with a good soldering iron and some flux.

Also some good 'no clean' solder wick.  The IC on the board will probably be very brittle (due to toasting it) and that could work to advantage removing it as it might break in half.  If you're not familiar with the process, there are plenty of tutorials around the web for replacing SMD parts.

Good luck.

[Felix]

Be extra careful when you remove it, so you don't lift the pads with it as well. I would just heat one side well, then lift it carefully, then the other comes off easily. My take is that if you try to forcefully remove it or break it apart, it's very likely you will lift or damage the pads...just my 2 cents.

[pyndot]

Thanks for the advice guys... That chip is not cheap here (Australia) relatively speaking. I might be better off getting a "Miniboost" off you and rewiring D5 to it then to Sensor 5V off the board. But how do you think that would affect the power consumption? Not that I am actually too worried about it for the device current use.

Also I notice that Miniboost is out of stock - is this because you are phasing it out Felix?

[Felix]

Miniboost is not meant for ultra low power so i would not recommend it for this purpose. Also it should be back in stock sometime soon when I get some missing parts.
Maybe the best option is to get a replacement SonarMote PCB but that would be more costly than getting the LTC3525 chip. Or ... I could arrange the LTC3525 chip to bundle in another order if you plan to place one in the future.