I'm wondering what PCS801S-2S means or even what I'm looking at from a power supply board for a Samsung led tv model un55d6000sf.
Note that many, many components on that board have "801" in their silkscreened labels. This implies that PCS801S, PCS802S, and PCM801S are nothing more than arbitrary reference designators assigned by the designer and likely have no intrinsic meaning, which is why no one could work from your original post. If you don't have the schematic, then you need to look at the markings on the devices themselves. Others have already provided the schematics and shown that all three are the same device, namely an LTV817M optocoupler.here is the power supply. just above the transformer are three ic's to the left together.