From The Jargon File (version 4.4.7, 29 Dec 2003):
gronk
/gronk/, vt.
[popularized by Johnny Hart's comic strip B.C.: but the word apparently
predates that]
1. To clear the state of a wedged device and restart it. More severe than
‘to frob’ (sense 2).
2. [TMRC] To cut, sever, smash, or similarly disable.
3. The sound made by many 3.5-inch diskette drives. In particular, the
microfloppies on a Commodore Amiga go “grink, gronk”.