Capacitor top has a plastic cover, bulging there is normal, just if it is pushed in gently and does not move will it be faulty. Would check high value resistors in that area, along with all the solder joints around the area, as well around T601 at the front, as that is the standby circuitry. Very commo for resistors to go high in value, and for the solder joints to get brittle and crack, especially with heavy parts like the LOPT, heatsinks and power resistors.
You can also get the service manual, by searching for the Samsung model number on the case or the board.