Yes, it is a lot of work to properly replace all of the capacitors in Predictas, but if that is not done, the set may not be very reliable. These articles show what I did to restore a couple of different models (one 21-inch, the other 17-inch).
http://antiqueradio.org/philc12.htm
http://antiqueradio.org/PhilcoH3412L...Television.htm
Not knowing exactly what was done, it's hard to say whether the previous owner did a thorough job. Predictas were known for being somewhat unreliable even when fairly new.
Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html