leenew wrote:Seeing as I am still a bit confused, are all the buttons where they should be?
Out of interest, what's the middle 7a22 rack for?
Yes, looking at the pictures, all the important controls appear to be set to reasonable values.
Rack 7a22 is a differential amplifier and by the looks of it, it includes low pass and high pass selectable filters.
Normal inputs measure the input voltage with respect to ground. On mains powered 'scopes, ground (the outer connection on the BNC sockets) is internally connected to both the case, and to the earth connection in the mains lead.
This is not a problem if the equipment you are working on is also earthed, or is earth free and double insulated and this equipment uses an isolating transformer, or is only battery powered.
However, some mains powered equipment operates with voltages that are not referenced to ground (so called live chassis televisions for example). In this case, you cannot connect a normal 'scope input (as you will then try to ground the circuit you are connecting to, and either cause a shock hazard, or short circuit part of the circuitry). Some double insulated mains powered items also are effectively in this class.
So you have to either use a differential adaptor between the 'scope and the equipment you want to test, use a 'scope with a differential amplifier, or use a large isolating transformer to power the equipment you want to test.