The celebrity "Mr. Fix-It" leans over as if to confide a dark secret. Out of his mouth, it's a surprise:

"Home repair is really a bore," says Al Ubell, magazine and book do-it-yourself writer and frequent guest on TV's "Good Morning, America."

Not that a lot of us stumble-fingers didn't know that years ago. But, boring or not, the high cost of repairs is forcing even the most reluctant to wield a wrench and a screwdriver in the hope of saving a few bucks. Even if they don't want to be bothered, two-career couples often can't be home during the daytime hours most repair workers insist on.

Which leads to Ubell's latest endeavor. He has been hired by General Electric to promote the company's new "Quick Fix" program aimed at guiding appliance-buyers in making their own repairs on GE and Hotpoint washers, dryers, dishwashers, refrigerator-freezers and ranges.

Ubell acknowledges that it is unsual for a consumer adviser to accept an offer like GE's, and the potential for conflict of interest gave him some worry. But he was also intrigued by the idea of an appliance manufacturer taking steps to ease customer repair costs.

"Traditionally," he says, "the appliance industry at large didn't like the idea of anybody who could repair their own appliance." They would all but paint a "skull and crossbones" across the machinery panel "to frighten the ---- out of everybody."

At the same time, anybody who did attempt a home repair discovered how hard it was to find replacement parts. "You would have to travel half-way across town for parts to fix a washer."

The "Quick Fix" program meant a break from that pattern. "After a little soul-searching, I decided to promote the concept."

Americans, Ubell believes, "are becoming less mechanically inclined" as our homes fill up with new and more complex gadgets. When a device doesn't switch on, they phone for a repair worker who charges $30 or $40 just to show up. Often--to the homeowner's dismay--the problem is simply an unplugged cord, or "there's a kinked hose on the washer."

Children, he says, "should be encouraged" to learn the repair skills that will be invaluable to them as adults. "Parents have a tendency to say, 'Don't touch that. Your father will kill you if you break it.' It instills fears."

What "Quick Fix" amounts to are self-service displays in GE dealer showrooms around the country. These displays carry heavily illustrated, 100-page repair manuals ($6.95 each) for the five major GE/Hotpoint appliances. There is also a selection of the 94 "most-often-used" replacement parts, which the company says cost between $2 and $30.

If, for example, your electric range won't heat up, the step-by-step manual for stoves has a diagnostic chart suggesting four possible causes, including a blown fuse or a defective power cord. It then gives the repair procedure--rated "easy" to "very difficult"--for each. In some cases, you still are advised to call a service technician.

"The typical service call to repair a home appliance today," says GE, "runs from $50 to $75. In about half the cases no parts are even needed to make the repair. If a part is needed, one costing less than $20 usually solves the problem. And many repair jobs . . . are simple enough for the skill of the average homeowner--if he or she has the proper guidance."

With the manuals, Ubell--who has none of the five GE appliances in his Brooklyn home--says he was able to strip down and reassemble each kind at the GE factory before he began his 24-city promotional tour.

Sure, he says, GE expects to make money off the "Quick Fix" program, but he hopes other manufacturers will come up with a competing alternative, which should benefit all consumers.