Two of the solar panels did unfurl and theoretically are producing power. Perhaps not enough to run all the instruments, but it's something and it's possible could be keeping the batteries charged.
Most of these probes, sensing loss of communication or other problem, go into a 'fault mode' where the bare minimum is kept going until instructions are received. The probe itself might be functional and alive, just with low power and unable to communicate with it's primary array.
I wonder if there is another way to communicate now that we know what's going on? Remember Gallileo had a problem unfurling it's primary antenna and was able to communicate, although much more slowly, through a secondary, low-power antenna.