Try this one. Today it was working
Jakarta to Surabaya is a long way. BIMA is a direct train which leaves 17.00 hrs but then you will miss the most beautiful part Bandung-Yogyakarta by daylight.
Better to do the trip Jakarta-Yogyakarta by day, take a break fo ra couple of days in Yogya and then furtheron to Surabaya.
It's wise to buy your ticket one day before your departure.
Trains from Jakarta depart from Gambir (also from other stations but Gambir is one of the most suitable)
For Surabaya Gubeng or Kota are the most usefull ones.