Lime2: Broken PWR button & no poweron

[lampra]

I have a Lime 2 and
1) 12 volt were applied for 15-20 seconds
2) the POWER button is broken .
I try to power it up using the battery or the power jack, but the LEDs do not light up.

Should I consider it completely broken/unusable or is there any other way to check?

[LubOlimex]

Probably part of the power circuit got damaged. LIME2 is 5V only board and 12V would damage certain parts.

If the board doesn't get powered by neither PWR_JACK nor battery over the LI-PO connector then probably the AXP209 got burned. Inspect the schematic for what might have got damaged on the way in.