What's going on with this transformer?

[AgentDelta]

I'm troubleshooting an A/V receiver that uses a transformer with three sets of outputs, marked AC12, BL, and BH. When I look at each of the outputs on an oscilloscope, the AC12 and BH outputs look roughly like what I would expect to see, but the BL output waveforms seem out of sync with each other (see the attached screenshots). Any ideas as to what's going on with the BL output?

I haven't been able to track down a spec sheet for the transformer, so I don't have any official word on what each output is supposed to look like. Any help understanding what's going on with the BL output (I'm mainly trying to determine if there's something wrong with the transformer, and if so, what's wrong) or pointers to resources I should be looking at would be greatly appreciated. Thanks!

[Analog Kid]

2nd pic shows the two voltages exactly 180° out of phase, in other words polarity reversed.
Dunno about the 1st pic; that looks more problematic (not 180° out of phase).

[AgentDelta]

Yeah, that first pic is what has me concerned that something's wrong with the transformer; I just don't know what might cause output like that.

[ejeffrey]

I would guess that the winding is floating.  There is still some signal because of the interwinding capacitance but you get a bug phase shift.  Use an ohm meter when the transformer is deenergized to check for the winding configuration.