After five years of waiting for the fax fad to fade, the market at last has acknowledged that demand is here to stay. The unofficial imprimatur is the arrival of a manual that describes not how to shop for a facsimile machine but how to find and fix what went wrong with the one you bought.

Among the first fax do-it-yourselfers is this fall's Troubleshooting and Repairing Fax Machines (Tab Books, Blue Ridge Summit, Pa.; $16.95), whose author, Gordon McComb, a veteran dissector of VCRs and similar electronic devilment, plunges into the intricacies of failing faxes with an illustration-backed confidence that laypeople will find catchy, convincing, and easy to follow. Considering that a fax machine is apt to need service as frequently as a laser printer or an electronic typewriter -- about one and a half times a year -- learning to perform even a minor repair (for example: "Soldering Tips and Techniques") will sooner or later cover the price of the book. -- Robert A. Mamis

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