[Elecraft] K3 Firmware - help!

[Nick Henwood]

After no previous trouble, I  had slight problem since installing 1.96/1.73 - when first switched on, tuning seemed to cause disconnection of all signals - no problem after a few seconds.
Now - have just lost everything - stuck on one band, no signals, buttons do not work for their assigned purpose and can't get access to menu. Presume I need to reload firmware - how do I go about that please? Thanks.
73 Nick G3RWF