PC World Business

If you recently purchased a Sony LCD (liquid crystal display) or rear-projection television, you may want to check the model number. A problem in the firmware for these televisions means they will stop operating normally after 1,200 hours of use, according to the company.

The firmware problem causes the televisions to either not turn off or not turn on after 1,200 hours of operation, according to Sony. Customers who purchased LCD or rear-projection televisions in Australia, Asia, including China and Japan, or North America before November 2005 are potentially affected by the problem, the company said.

The flaw may exist in 400,000 television sets, Sony said. It is offering free firmware upgrades to customers affected by the problem.

Sony advised those who have already experienced the problem to unplug their television sets from the wall for at least 30 seconds. The televisions should automatically reset and the problem will not occur for another 1,200 hours of operation, it said.

Australian customers can check to see if they are affected by the problem, and register for a software update to fix it by visiting http://www.sony.com.au/category.jsp?id=30546.