Perhaps the sudden locking up caused a gear to break internally? But how would the PO know this? Has he been inside to check? I've seen several owners think the gear box was broken .... when all that was the matter was the shift lever was bent!
Obviously, if you currently have no 1st or 2nd gear ... you will have to go inside to know what exactly is broken and what needs replacing. It's a big job and not for the inexperienced or faint of heart. The gears are about $50 each to replace ... plus some additional damage may have been done ... so a crap shoot.
On the DR650 it's usually 3rd gear that can fail. But of course this is quite rare overall and seems mostly to affect bikes imported to Australia.
Good luck on this .... What is your plan going forward?
