Fritzed Garmin eTrex HC - Help?

evil_breakfast
evil_breakfast Posts: 470
edited March 2011 in Commuting general
Just had a call from my housemate whose (aforementioned) Garmin unit has decided to give the ghost.
Bit of background is probably required.
Said housemate decided to press gang said unit into service as a (cheap/ad-hoc) sat-nav, powered by a normal cig lighter to USB connection/lead
Apparently, first trip out tonight to Bath, and the unit has now shut off completely and can't be turned back on again.
Even with USB cable removed, and batteries inserted.
Any ideas?
Or is it muellered?
You're the light wiping out my batteries; You're the cream in my airport coffee's.