Hi,
New to this forum and thanks for helping if any idea:
Mine has a strange behavior : when power up, let's say, once a day, it works for a while, then signal is superseeded/mixed by a sine like signal, 25Khz ~20PP
Very strange, I have tested all my probe, both channel, cable between generator and probe etc...
I'm in audio (modular synth), and mainly using this scope for audio signal visualisation, no high frequency.
don't know what to look after inside the scope to fix.
Below, same signal (2 probes from same point), bare square wave: FnIRSI and old Hitachi scope