DL4 says 'krkrkkkrkrkrkrkkkr'

[nick <tranquillitybass@clear.net.nz>]

hey loopers

i just bought a second hand (2yr old) DL4 and have found badness ocurring.

Whenever the processor is engaged it makes a loud 
static/whitenoise/kkrkrkkrkrkrk
kinda noise that is nearly as loud as the effect sound. 

Are there any DL4 users out there who have come across this?