Hameg 1004-3 Time/div problem

[Amine13]

Hello Friends,
First topic !!
Well, the time DIV button at the right doesn't behaviour normally, when I turned to rise time div, it doesn't respond, and finishes by goiing to the min value which 50ns then starts to beep, turnin to the opposite direction doesn't affect.
  Can the knob be faulty?  and If yes, is there somwhere to get spare parts for this scope?
All the best.

[cnqhdszq]

You may have a try  press the "auto" botton.