A Rockville electronics firm accused by Montgomery County of running deceptive advertisements in the Yellow Pages has agreed to pay $1,250 to settle the complaint, the county consumer affairs office said this week.

Under an agreement reached Sept. 8, Solid State Electronics Inc., of 12366 Parklawn Dr., will pay the county $1,250 to settle a complaint that it misrepresented its services in ads in the 1982 suburban Maryland Yellow Pages.

Solid State ads described the firm as a factory service center for eight major manufacturers of stereo equipment when, in fact, it had no such factory sponsorship, said Lawrence Breedon, an investigator for the consumer affairs office.

The county investigated the firm because unauthorized repairs during a product's warranty period could jeopardize future warranty protection, Breedon said.

The investigation was prompted in March by a consumer's complaint about repair service he received at Solid State, Breedon added.

As part of its agreement with the county, Solid State agreed to refund the $264.12 the consumer spent on stereo repairs. In return, the firm was not cited for violating Montgomery's 1972 consumer protection law, officials said.

Solid State president Steven Browne said he intends to comply with the agreement. The firm has made one $200 payment toward the settlement cost, Browne and county officials said.