Samsung Electronics Co., Ltd. Informative - Capacitor problems causing power supply to shutdown/dots on screen
There is a common problem with power supply issues in many models of flat panel Samsung TVs. Capacitors that were used are either too low a voltage, or the capacitors were of poor quality (there doesn't seem to be a consensus), and they fail prematurely. This results in either a bulging of the top or side (shown here) or a "leak" - a dark colored substance will leak out somewhere around the component.
This is a failure that Samsung appears to usually not pay to repair once a set is out of warranty, though there are cases where they have. It is worth asking them. It is a straightforward low cost ($10-15) do-it-yourself fix for those with soldering skills and awareness of safety when working on electrical appliances and electronics. A novice should not attempt the repair. A partial list of affected sets (unverified) is shown. The fixes others have done can easily be found by Googling "Samsung capacitor fix".
Typical failure symptom