Oscilloscope potentially ESD striked
I have a Rigol DS1104 oscilloscope. Last week I stood up quickly from my table and saw a spike on the scope. Right now all the channels have a DC offset when probe is connected to ground or unconnected or measuring anything. Changing the vertical scale changes the offset. At 500mV all channels show 1.2V when grounded, at 1V 680mV, at 5V it shows 4.4V etc.
I haven't noticed anything else out of usual besides this. Test signal provided by the scope works, aside from the DC offset.
To check that this isn't some weird setting, I performed a factory reset on the scope and the issue persists. The next steps would be to contact manufacturer and send it in for repair, however, I need a scope ASAP. Therefore, I am wondering how difficult could it be to repair it myself. What could be the reasons for this DC offset on all channels, and what are the chances of repairing it without sending it off?