The Great Power Blackout of '78 was cleared up in Bethesda yesterday, but not before some 2,000 business and residential customers had a chance to spend Tuesday night eating by candlelight and sleeping under extra layers of blankets.

A power failure in New York might prompt fears of chaos, but the chief complaint in Bethesda yesterday was about the messy inconvenience of the whole thing.

"I managed to keep the refrigerator door closed so the food wouldn't spoil, but walking up to flights of stairs and taking a cold shower this morning is not something I'd like to do again," said 21-year-old Michael Banasak. He lives in the Four Seasons Apartments, at 4710 Bethesda Rd., where power was not restored until 2:20 p.m. yesterday.

Banasak was just one of many people in Bethesda who had to bundle up or take extra measures to deal with the power failure, that began shortly before 4 p.m. on St. Valentine's Day.

It began Tuesday when an underground defective cable on Old Georgetown Road at Cordell Avenue caused four other cables to short-circuit, cutting off power to a maze of lines that feed electrical power to the downtown section of Bethesda.

As electric company workers worked feverishly to repair the cables, guests at the Holiday Inn in Bethesda were told they would have to use extra blankets to keep warm when they registered Tuesday night at the candlelit front desk.

One guest, who said she had traveled here to attend a health educators' conference, said, "Most of us were tired of getting snowed in and snowed out of cities that his blackout was almost welcomed."

"The only bad part," she added ". . . was the cold shower this morning."

Another guest obviously was less than pleased with the blackout.

"I couldn't read my material for the conference by flashlight . . . so I called a friend and stayed at his house," he said.

A flashlight was all the night teller at the Bethesda Suburdan Trust Bank needed, however. He used his flashlight and a telephone to conduct business as usual Tuesday night despite the blackout, employes said.

And when Trent Well Restaurant owner Tasos Scilaris found that his refrigerator had shut off, he said he moved the stored meat to the trunk of his car where the cold weather provided natural refrigeration.

But ingenuity couldn't help employes of the Postal Instant Press, at 7558 Old Georgetown Rd., who first found they could not use their electrically operated printing equipment and then had to face disgruntled customers yesterday.

Among those affected by the power outage were employes of the National Institutes of Health's Bethesda headquarters, who were given the day off. People turning up for work in the Air Rights Building arrived only to discover that the building had been locked on the orders of the fire marshal. Police reported no crime during the shutdown.

The spirit seemed definitely upbeat, however.

"We're half frozen and half blind but we're still open," read a sign on the door of a local camera shop.