Just about a month before television stations were scheduled to shut off their analog signal and switch to digital broadcasting, president-elect Barack Obama asked Congress to postpone the federally mandated switch to all-digital broadcast television, called DTV, scheduled to take place Feb. 17.

The incoming administration is warning that the TVs of millions of Americans could lose their pictures because of problems in the government's preparations.

The move follows the announcement this week by the Commerce Department that it had run out of money to provide $40 coupons for low-cost converter boxes to allow older TVs to receive the new digital signal. To complicate matters further, the coupons came with a 90 day expiration date and more than 13 million expired.

Those with expired converter box coupons cannot get new ones, unless they use a different address. According to Nielsen, a media research company, about 7.8 million households or nearly 7 percent of people with TV's are completely unprepared for the deadline.