Cambridge soundworks dtt3500

[beamnet]

Hi all,

I am usually in the tubes corner of this forum, but recently a friend gave me this unit to repair.

It works fine, but after a minute of playing, blips and squeeks are clearly audible on all channels.

So this sounds like a digital problem.

It makes the noises if both analog and digitally connected, and on all settings.

Visual inspection did not turn up any problems.

Anybody in for a guess where to start?

Bas