Semi-broken KD50

My KD50 just broke today... it only outputs about 1mw now..
I've checked the battery, connections, etc.. and everything looks fine.
Disassembled it completly, reassembled, realigned and still the same.
What can be the problem? The IR diode, the crystal or the driver?

Most likely the diode.

If nothing happened when you re-aligned the crystals, it sounds like the diode is fried. Great pictures by the way.