Power cords for old TVs can be difficult to find these days, because they aren't used much anymore. The AC cord is hard-wired to the chassis in almost all new TVs, and probably all flat panel sets as well. The instruction manual for my flat-screen TV, for instance, makes a particular point of this fact: "The (power) cord is permanently attached to the back of your TV. Do not try to pull it out."
As to a cord that can handle the current draw of a 540-watt (!) television, as was mentioned in another post, you may have to do a lot of looking at flea markets, hamfests, etc., as just about everything these days is solid-state and powered either by a wall-wart transformer or an internal power supply -- as I said, there is almost no need anymore for the type of power cord formerly known as a "cheater" cord. This type of cord got its name from the fact that it was used, in the days of tube-powered TVs, to power the set for servicing when the back cover is removed. All older TVs, until about the '80s or so, had what is known as an "interlock" cord. This cord had the socket end riveted to the fiberboard back of the TV; it mated with a 2-prong connector on the television chassis when the back cover was attached to the set. However, when the back was removed, the socket parted company with the chassis-mounted connector, cutting off all power to the TV. Many people, however, defeated the purpose of this interlock (when the set's cord became frayed or otherwise damaged) by removing the socket end of the cord from the back of the set and using a cheater cord; this dodge got the television to work, but it disabled the safety feature provided by the interlock.
This is most likely why today's flat-panel TVs, and many sets made from the 1980s until the end of the analog television era, have permanently attached cords and clearly worded warnings against removing the back of the set for any reason -- a throwback to television's early days, when such a warning was found on the backs of all TVs of the time: DANGER. HIGH VOLTAGE PRESENT. Do not remove this back for any reason. This cover is only to be removed by qualified service personnel.
Five hundred forty watts is over a half-kilowatt, so the set for which VK member earlyfilm needs a replacement cord must be a 3-way combo entertainment center with a very, very powerful amplifier; that's the only thing I can think of that would cause any television to draw that much power from the AC line, unless the set had a very serious short circuit. However, in the latter case, the line fuse (or in sets not equipped with such a fuse, and there were many 1940s-'50s TVs that were not so equipped, the house fuses) should blow immediately. There are cases on record, however, where foolish homeowners have replaced fuses in the basement fuse box with copper pennies; this may have restored the power, but the severe overload on the power line often caused fires when the wires behind the walls in the house overheated. There was one such case mentioned in a DIY TV repair book of the 1960s. In 1963, a house in Cincinnati, Ohio was severely damaged by a fire caused by overloaded wiring; the overload, in turn, was caused by a thoughtless homeowner who, having grown weary of replacing fuses when they blew, put a copper penny behind the fuse and reinserted the latter in the fuse box. Once again, this restored the power on that circuit, but the wires in the walls and elsewhere in the house overheated, the insulation burned off and a costly fire resulted.
Today's electric service panels for homes, businesses and other public buildings are designed such that such a disaster as I just described cannot occur. These boxes use circuit breakers that are permanently bolted into the box with hidden fasteners, so the only thing the building owner can do when a breaker trips is to flip it back on -- after the overload or short circuit has been cleared, of course. If the overload is not cleared, the breaker will continue to trip until the problem is corrected. There is
no way whatsoever to bypass or otherwise defeat the breaker, without destroying the box.
Whomever invented incorruptible breaker boxes is to be commended many times over, as these boxes cannot be "fixed" to defeat the breakers; this, in turn, has resulted in a drop in the number of electrical fires in homes, businesses and the like. In fact, I believe the National Electrical Code (NEC) now requires that breaker boxes, not fuse boxes, be installed in all newly constructed buildings.