I've gone through a few other threads where wrong V2 voltage is mentioned, but they all seem to end up being different issues.
My current problem is that I am getting a small negative voltage at V2 (about -200mV). All other voltages seem normal. AV+ and AV- are normal.
I'm not sure where to go from here, as all the other threads I've seen have had an unusual AV- voltage.
Edit: I should add, touching the probe to the test loop has no effect. At one point I accidentally touched the ground probe to the AV- terminal and this actually produced a change to the trace voltage and caused the trigger LED to illuminate, but that's the only time I've seen it do anything. I thought maybe there was an issue with the test loop, so I connected the probes to a headphone audio output but saw no signal there either.
I have access to a multimeter but don't have another scope to test with.