April 14, 1986

Just when everything was in place and everyone was primed for the big upset, the Flyers - that team that thrashed the Rangers during the regular season - reappeared. And they did it in a blowout. They beat the Rangers, 7-1, last night to even their three-of-five-game Stanley Cup playoff series at two games each. An evening that had all the festive trimmings and promised to be a momentous one at Madison Square Garden just never developed that way.

There are 19 buildings at Jacob Riis Houses, each a red-brick world with its own community, its own spirit. In one, neighbors are so close that one family adopted the children down the hall when the uncle they had lived with died. In another, there is so little contact that a mother could not give any neighbor's phone number to her child's day care center in case of an emergency. Like most of the buildings that make up Riis Houses, a city housing project on the Lower East Side, 90 Avenue D is neither so familial nor so foreboding. There are people like the caretaker, Julio Gonzalez, who chase drug addicts from the building and there are dealers who bring the same addicts back. Talking About Action There was a time when 90 Avenue D was known as the worst of the buildings at Riis. The walls were smeared with graffiti. Addicts and dealers, who had turned Avenue D into a narcotics bazaar, were using the building regularly to do business. They shot up and nodded off in stairwells and on doorsteps. They mugged residents to get money for a fix. One time, an intruder high on drugs stabbed a woman 11 times and threw her out a window.

A third suspect in the holdup-murder of a jeweler in Manhattan's midtown diamond district has been arrested and a fourth is still being sought, the police said yesterday. Acting on information supplied by two suspects seized in a running gun battle after the slaying Friday, detectives arrested the third suspect, Felix Perez, 36 years old, at his home at 60 Euclid Avenue in the East New York section of Brooklyn at 4 A.M. Saturday. Mr. Perez was charged with murder, attempted murder of a police officer, assault and attempted robbery. The same charges were lodged Friday against Alfredo DeJesus Feliciano, 31, and Ersal Lebron Hernandez, 34, in the fatal shooting of Moshe Ashkenazy, 57, the owner of the Aeze Jewelry Manufacturing Company at 33 West 46th Street.

When Sir Clive Sinclair sold off his computer business last week, it had to be the most widely followed $7 million corporate transaction in British history. The announcement last Monday received extensive coverage on television news programs that evening, and the story was at the top of the front pages of most London newspapers the next morning. A headline in The Times of London said: ''Sinclair computer sale ends an era.'' For Sir Clive, the inventor who developed the pocket calculator and some popular home computers, the sale effectively ends his efforts to head a business. He will now concentrate on doing contract research for other companies and generating product ideas.

The General Motors Corporation, as expected, began a broad round of low-rate financing sales incentives today in an apparent effort to avoid cutting back production. James G. Vorhes, G.M.'s vice president of sales, said he expected the new incentives to ''give a strong new spurt to the market'' during the spring selling season. The announcement of the new program, with rates as low as 6.9 percent, came a day before prices of G.M. cars are set to increase an average of 2.9 percent. While G.M. has not released details of the price increases, which would average about $350 a car, the new financing program appears to nullify the effect of the increase.