I have a few questions:
First
Does anyone know what the electronic board is this….
Or what electronic board this homemade electronic board is based on?
Best Answer
Just some bog standard protoboard with components soldered on. It's not a specific commercial/off-the-shelf PCB or development kit.
No idea what it does - it appears to be some sort of 555 timer circuit. The 555 timer is a TI NE555P, while the chips on the right appear to be Fairchild FOD817 optocouplers (based on the Fairchild logo and the number 817). You'd have to remove it from the case and trace the connections to find out the circuit.
The component you're describing is a tantalum capacitor. Read more here. It works like a regular (e.g. electrolytic) cap, probably in this circuit its function is to make the power supplied to the device "cleaner", as the GPRS module may draw lots of current in short bursts, so the capacitor acts like a short-term power reservoir. The tantalum caps allow for much more capacitance per unit of volume than electrolytic ones, but they're notorious for their narrow voltage tolerances and a spectacular thermal failure mode, which you've witnessed. Basically if you abuse them they burst into flames, sometimes sending small pieces of flaming material into the air.
It's much better for the board you if you replace it with a working one.
As per the general safety question, the technology of tantalum caps is safe enough to put them in nearly all mobile phones nowadays (as phones are too small to allow for an electrolytic cap). But in the hobbyist setting there have been cases of exploding products due to poor circuit design. Most famously and Arduino GPRS or GPS Shield (the official, branded one) designs from a few years ago had a lot of exploding specimen.
Best Answer
Just some bog standard proto board with components soldered on. It's not a specific commercial/off-the-shelf PCB or development kit.
No idea what it does - it appears to be some sort of 555 timer circuit. The 555 timer is a TI NE555P, while the chips on the right appear to be Fairchild FOD817 optocouplers (based on the Fairchild logo and the number 817). You'd have to remove it from the case and trace the connections to find out the circuit.