Jolt.js charging circuit damaged

[ZacharyLightman]

I was not careful and I plugged a lipo in the the jst connector that was the opposite polarity. the jolt still functions when powered any other way but I would like to repair it. Is it possible to get the schematic? I also have another jolt.js that failed, but I don't know how or when, I had been powering it through the terminals and left a battery attached, It is possible that one of my kids was messing with it and unintentionally shorted the board through the exposed pads on the bottom of the board(it was attached to a metal robot chassis). It would be helpful to have a schematic for troubleshooting. for now I will use my mostly working jolt and I have ordered another.

[gfwilliams]

Hi,

I'm sorry about that - and for the lack of schematics too - I'd put them online but not linked them from the Jolt.js page! Check out: https://github.com/espruino/EspruinoBoard/tree/master/Jolt.js

There are PDF but you should also be able to use Eagle CAD (or KiCAD can import I believe) to view the original schematic and board file.

If the LiPo charger has gone it's super simple - just an LGS4084HB5 that I think you'll need to replace (but ideally you need a hot plate or air gun for that as it's a bit tight). Does the Jolt not work when the battery is plugged in? Or is it that the LiPo charger gets hot?

For the other board failing, that's a bit of a concern. I'd hoped that apart from the small chance of shorting one of the row of small circular contacts on the back, it should be pretty safe. The first thing I'd try is to get a 3v power source and try and power the microcontroller, and see if the red LED blinks once and it's connectable. Just use GND on the terminal block (or the screw one) and then VCC on Q0 or Q1 (or the little gold circular contact nearest the middle of the board).

If that's the case then it'd be a voltage regulator issue I guess - although the only time I've seen those die is when the voltage spikes above 18v.

[ZacharyLightman]

Thank you for the quick response! I will attempt to diagnose the failed board with your recommendation. I do have access to a hot air gun and a professional soldering station at work, so repairing that board should not be a problem. The schematics will certainly be helpful ! I will reply after I investigate these issues.