May have just fried the compressor. Had just started a manual run at 6pm, with 64 watts coming in and battery voltage 25.9, when I heard something unusual (dunno what; radio was on) from the fridge and the compressor shut off. Its run light was still on, tried one more brief power cycle and still not turning on.
I suppose I'll know tomorrow morning when there's full solar power, if it doesn't come on.
Smelling the compressor ventilation area, it does not smell promising..