A Plasma TV With No Picture & Making a Clicking Sound

Technology site Ars Technica reports that consumers who purchased some models of plasma and LCD TV sets in the mid-to-later 2000s began hearing clicking sounds from inside the units when they tried to turn them on. What began as a single click and a pause at startup turned into multiple clicks and longer delays. Eventually, many of these units failed to power up at all, and some shut off spontaneously and powered back on. The failures, which typically occurred after the TVs' warranty coverage ended, traced to bad capacitors mounted on the circuit boards that powered them.

In the mid 2000s, an epidemic of bad capacitors left electronic devices, including computers and TV sets, with problems that emerged three or four years after purchase. Capacitors act like short-term batteries, temporarily storing electrical charges. Inside its enclosure, a capacitor contains two conductors with an insulator between them. In power supplies, these small components help supply a consistent amount of electricity. Failed capacitors show a bulge at the top, where an X-shaped vent releases gas that builds up inside as the oil these devices contain breaks down, or a leak in a seal at the bottom, disclosed through discoloration on the circuit board to which the capacitor mounts.

Some capacitors fail because they lack the ability to contain the voltage levels to which they become exposed in the electronic devices that contain them. Other capacitor failures result from defects in materials or manufacturing. Heat exposure from inside the case of a device that uses the capacitors can shorten their lifespan. If the power supply in which they're installed lacks the ability to provide sufficient support for the device it runs, the strain of trying to operate under these conditions can also damage electrical components.

Some plasma TV sets affected by power-supply capacitor failures received free repairs through a class action suit filed against their manufacturer. Repairing these problems requires one of two approaches. If a power supply consists of a sealed unit, a technician may replace the entire component. In some cases, the best -- but not the simplest -- approach lies in desoldering the faulty capacitors, cleaning the circuit board of remaining solder, and then installing replacement capacitors. The fix requires a suitable soldering iron, desoldering tools, advanced soldering skills and the right parts. Because capacitors can store potentially lethal voltages of electricity, executing these repairs safely demands experience and knowhow.