When my 6000 had a glitch two years ago, the dealer tech recommended sending it in to Deere to be remanufactured.  Think the price then was around $1,500.  Ended up not going down that path as he screwed around with back in the office and resolved the tidal error.  Is your 6000 dead-dead as in no LEDs, no communication with the display or have some error code(s)?