NASA lost contact with their STEREO-B satellite nearly twenty-two months ago when performing a routine test. NASA scientists are afraid to turn on the computer at this point because it may cause them to lose contact again.
What's the point of being able to talk to it if they can't turn it on and actually do stuff with it?
If they thought they lost it 22 months ago, they have nothing further to lose if it goes away again now.
Reading the article helps determine what the point is...
Seems the point is that they want to try to see if there is something they can do to point the satellite at the Sun in the 1 to 2 minutes they think they might have before the startup of the computer drains the battery and they have to wait another 6 months until the battery randomly charges up as it gets sunlight on its solar panels at the wrong angles. The sensor that keeps the satellite pointed at the sun failed, but maybe they can keep it pointed at the sun by sending commands from Earth and then they can better assess the health of the systems with more time.
Based on the article its seems they might have just enough time to give it some commands to point toward the sun and then hopefully the battery starts charging up again so they have more time to work with before it powers down.