Mikayla

So I've tested the oscilloscope by having it measure a steady 5V power supply that my multimeter measures no problem and it just measures noise. Negative power supply, as tested by my multimeter won't output consistent power at the correct voltage - I tell it to output -5V and it'll start wildly fluctuating between positive 2 and 10 volts. Since the negative power supply won't work, I tried using the second wave-generator as a DC source. I put it in DC mode and tell it to output -5V. It too just starts wildly fluctuating giving me all sorts of strange readings that make it clear it's outputting some sort of AC power when it's supposed to be outputting DC. I'm posting on here because it says I have to in order to get a warranty replacement. How do I do that?