I am working ona toshiba tp4871b with no schematic. Im trying to
rebuild the vertical circuit changing caps and IC"s. I tried to get a
schematic from samswebite.com and they called me and told me they dont
have it. So now im just looking parts up to see what they are to try
to find the vertical circuitry.

The part in question is labeled like this:

STR
S6421
SK2312A

Its mounted vertically and has 8 legs and a massive heat sink.

Searches on google have turned up nothing in data sheets or the part
description. Any help is appreciated.

TIA!!