Thanks you very much for this "hard to find" service manual.
Will help a lot in repairing this tuner.
Text excerpt from page 34 (click to view)
selection, the format that is corresponded with the input HD SDI signal within the format according to the selected bit by S704 and S705, is selected and is set. The DPR-151A board mounts the switching regulators of the +3.3 V, +1.2 V and _2 V and the series regulator of the +2.5 V as a power supply circuit. These voltages required as the power supply for ASIC are generated by DC-DC converting the +5 V and _5 V voltages that are supplied from the mother board of PFV-HD50/HD300.