Lime Mini Overvolts - whats the chances...

[radiogareth]

Whilst investigating the suitability of a 4-way switchable USB3 port extension (with a DC in 8-12 volts socket) to see if it provided decent robust '5 volts' when powered by 12 volts (rather than the 5V coming from the RPi) my Lime Mini let some of its magic smoke out. Close inspection shows what looks like a roasted inductor on the Likme Mini.
Has anyone suffered (and fixed) this issue I wonder?

2020-09-23 12.05.57.jpg (105.6 KiB) Viewed 2127 times

Or have I got a 'dead-un' now
Gareth

[G8GKQ]

Hi Gareth

My commiserations. That looks like a Version 1.3 LimeSDR Mini, which has different power supply circuitry to the V1.2 Limes supplied through the BATC Shop.

Is the inductor open circuit? If so, it might be worth trying to replace it. You might find the value on the LimeSDR Hardware schematics here: https://github.com/myriadrf/LimeSDR-Min ... rdware/1v3, although you'll need to put them into the Altium reader website to read them.

Dave

[radiogareth]

Thanks for the link Dave, its still showing as 0.1 or 0.15 ohms, the Lime mini draws 1.5 amps (on 5 volts) and the fan doesn't run.

A cautionary tale for others perhaps, not to overvolt a Mini. My Lime SDR has always been happy on 12/13.8 as its unreliable on USB power alone. It wasn't a dead cheap hub either - Sabrent HB-UM43 chosen as each port can be switched off.. Intended as power saving (portable ops) for the Portsdown/Langstone combo I'm trying to finish. Think I'll move to an 'unplug' option now
Pluto will be built in to the case to try and save wear and tear on the microUSB.
Onward, but poorer....
Gareth

[G8GKQ]

OK Gareth

Don't throw it in the bin. I also have a Lime Mini V1.3 with a similar fault (draws over an amp at 4v) and I will try to recover it at some stage. I'll let you know if I get anywhere.

Dave