BY PEELING OFF some of the punitive tariffs that he imposed on Japanese electronic goods in April, President Reagan hopes to give the Venice conference a modest boost. Current evidence, he says, indicates that the Japanese are no longer dumping semiconductor chips -- that is, selling them below cost -- on the same scale as previously. That enables him to lift some of the tariffs that were the American response. It's a useful gesture toward his embattled friend the prime minister of Japan, and it's an answer to the accusations that the United States is turning protectionist.

But it doesn't go very far. Neither the Reagan administration nor, to be fair, anyone else has a good, quick solution to the troubles of the American semiconductor producers. Their Japanese competitors are very large integrated companies that routinely use the profits of older products to hold down the prices of new ones in order to capture markets. Most of the American companies -- with the notable exceptions of IBM and AT&T -- are independents, with far fewer financial resources and frequently less exacting standards of manufacturing quality than those of the Japanese. In an effort to prevent the Japanese from dominating the world market for these essential products, the United States pressed Japan last year into an agreement not to sell anywhere below fair market value, and to buy more American chips.

From the beginning it was an unsatisfactory agreement, foggy in concept -- what's "fair" market value? -- and difficult to police. By this spring it was clear that the Japanese manufacturers were paying little attention to it. That's the point at which Mr. Reagan put prohibitive tariffs on a list of Japanese products worth $300 million coming into this country, of which he has now exempted $51 million worth as conditional acknowledgment of better behavior.

Perhaps that will help the Venice meetings go a little more smoothly. But the United States still has not found an effective way to deal with Japan's trading practices, and to persuade the Japanese that their insistence on inordinate trade surpluses is a threat to everyone else's economic stability. Nor has the United States decided how to deal with its own semiconductor industry. It's essential to the country's future, but, as this episode has demonstrated, important parts of it are less strong than world competition requires either in terms of financing or, more important, of manufacturing ability