Did you connect the battery to the transformer (L1 and L2) primary windings inputs?
Or to the output terminals; OUT+ and GND?
If the former, the transformers are likely destroyed (unless there was a fuse in series); replace fuse and check the primary windings resistance to confirm. If open, yer SOL.
If the latter, powerup (transformer primaries with mains AC) without anything at the output terminals and verify voltages from the transformer secondaries onward. That is, on the upper L1 part, check if there is +15 and -6.2 across either zeners (center tap being neg. of your multimeter). Check if there +2.5V across the TL431. On the lower L2 parts, check across C16 to give the rectified, filtered, unreg. voltage before the series pass transistors. On the bottom LM7812 regulator section (used for L2 tap switching), check if there is +12V across output and GND.