Electrical – SMPS Short Circuit

currentshort-circuitswitch-mode-power-supply

I am using an ATX SMPS to power my Orange Pi Plus 2 via 5V supply. It worked fine for a couple of days without problem until yesterday. I happend to connect my audio amplifier TPA3116 which worked fine. After which when i was switching some cables i happend to short the 12V supply. The smps immediately shut itself down.
Now i removed the short and disconnect the audio amplifier from 12V supply.

After this when i started the orange pi there was no more any indication. I wanted to know that if the 12V short let to an inrush current spike at the 5V power section. If any one on this forum is aware of fuses present on the orange pi board.

Best Answer

There is no way to know whether there was a spike or not, and it's hardly relevant. You have two devices (PSU and Orange Pi board) which don't work together anymore, and you need to find out which one is broken. This is easy: power your Orange Pi with a different PSU (e.g. a phone charger) and see if it starts up. If it doesn't, then most probably there was a spike which it could not handle.

Your PSU should also be checked with a multimeter to see if it still delivers 5V and 12V, and that these voltages didn't change. Check the PSU for fuses: there's a high chance you've simply blown one during the short, and replacing it will get things back on track.

Regarding fuses on the Orange Pi board, I don't think there are any, but you have to check: here's a link to the schematic (scroll all the way down). You need to register to download it, but it's free of charge.