TV’s Replacement Players : Television: The networks are scrambling to fix their lineups by replacing fall failures with new shows featuring George Wendt, Alan Thicke and Valerie Harper.

The February ratings sweeps have ended and spring is in the airwaves--at least at the broadcast networks, which will introduce 15 new TV series over the next two months, beginning this weekend.

This is the time of year when ABC, NBC, CBS and Fox play with their schedules and fling new programs against the wall to see what sticks.

Unfortunately for them, not much usually does.

The networks are looking for future hits while plugging current holes opened up by the failures of last fall. But the only hit series to emerge from last spring’s crop was ABC’s Ellen DeGeneres sitcom “These Friends of Mine,” which became “Ellen.” The season before, Chuck Norris’ “Walker, Texas Ranger” on CBS was the lone success story.

So, which new series will find a big enough audience this spring to warrant its return? That’s up to you.

* “The Great Defender”: This show features a blue-collar attorney with a heart of gold. No, it’s not a sitcom, but “an unorthodox legal drama” on Fox. Michael Rispoli (“Above the Rim”) stars as Lou Frischetti, who takes his night-school law degree from East Podunk to a stuffy Boston law firm and fights for the workin’ man. (Sundays at 7 p.m. on Fox, beginning this weekend.)

* “The George Wendt Show”: If Frasier can do it, why can’t Norm? George Wendt, the beloved barfly on “Cheers,” will give his own sitcom a ride. Like Kelsey Grammer on “Frasier,” Wendt hosts a radio talk show. He’s a mechanic who dispenses auto tips and advice with his bumbling younger brother, Second City’s Pat Finn. (Wednesdays at 8 p.m. on CBS, beginning next week.)

* “Hope & Gloria”: Cynthia Stevenson and Jessica Lundy play uncommon neighbors who bond over life’s common problems in this sitcom from a couple of former “Cheers” producers. Hope (Stevenson) bids farewell to her 10-year marriage as Gloria (Lundy) struggles to raise her 5-year-old son with her ex-husband. Making Hope’s life worse is her obnoxious boss (Alan Thicke), a TV talk-show host. (Thursdays at 8:30 p.m. on NBC, beginning next week.)

* “VR.5”: “China Beach” executive producer John Sacret Young, who only recently made the leap from legal pad to laptop, introduces a surreal series for the on-line age. Lori Singer (“Footloose”) stars as a wallflower who can probe minds by pulling herself and others into bizarre, virtual-reality landscapes inside her computer. (Fridays at 8 p.m. on Fox, beginning next week.)

* “The Office”: An “Upstairs, Downstairs” look at corporate office life. Valerie Harper plays a career secretary. Her secretary confidants: a working mother (Debra Jo Rupp), an MBA student (Kristin Datillo-Hayward) and a former Club Med worker (Andrea Abbate). The office suits are played by Dakin Matthews, Kevin Conroy, Gary Dourdan and Lisa Darr. (Saturdays at 9 p.m. on CBS, beginning March 11.)

* “Medicine Ball”: Intern Harley spots a misdiagnosis by the senior physician. Intern Danny’s patient dies. Intern Katie must perform a circumcision on a grown man. And hey, it’s their first day of residency! So it goes in this medical drama, Fox-style. (Mondays at 9 p.m. on Fox, beginning March 13.)

* “Under One Roof”: The first black family drama for TV since the early ‘80s stars Joe Morton and Vanessa Bell Calloway as parents in a multi-generational Seattle home. He’s an ex-Marine starting a new business; she’s his wife, making the change from full-time mother to working woman. James Earl Jones portrays Morton’s father, a widowed police officer with a foster child. (Tuesdays at 8 p.m. on CBS, beginning March 14.)

* “Newsradio”: Since radio talk characters are popular comedy devices these days, why not develop a sitcom full of them? Here, Dave Foley from “Kids in the Hall” plays the young director of an all-news radio station in New York. His charges include two flamboyant on-air personalities--Phil Hartman and Khandi Alexander. Creator Paul Simms was executive producer of HBO’s “The Larry Sanders Show.” (Tuesdays at 8:30 p.m. on NBC, beginning March 21.)

* “Pride & Joy”: In this contemporary comedy, two married couples are new parents. But the moms (Julie Warner and Caroline Rhea) work as advertising-agency partners, while the dads (Craig Bierko and Jeremy Piven) stay home--one because he’s a free-lance writer, the other because he’s unemployed. The title may change. (Tuesdays at 9:30 p.m. on NBC, beginning March 21.)

* “Sliders”: What if world history changed its course? Four adventurers find out each time they slide through a cosmic passageway to alternative versions of Earth. A physics grad student (Jerry O’Connell) accidentally creates the gateway in his basement. He’s joined by a computer tech (Sabrina Lloyd), a physics professor (John Rhys-Davies) and a reluctant R&B; singer (Cleavant Derricks). (Wednesdays 9 p.m. on Fox, with two-hour premiere March 22.)

* “Bringing Up Jack”: In this incarnation of the radio talk-show theme, comedian Jack Gallagher plays a host whose Philly fans tune in for sports talk and wind up hearing about Jack’s pregnant wife and two children from his wife’s previous marriage. (Previews March 28 at 9:30 p.m. on ABC; airs Wednesdays at 9:30 p.m., beginning March 29.)

* “The Wright Verdicts”: “Law & Order” executive producer Dick Wolf created this legal drama starring Tom Conti as former British barrister Charles Wright, now a prominent criminal lawyer in New York. His staff includes an investigator (Margaret Colin) and his trustworthy assistant (Aida Turturro). (Fridays at 9 p.m. on CBS, beginning March 31.)

* “Amazing Grace”: Patty Duke, perhaps known best for “The Miracle Worker,” plays a single mother who miraculously survives a near-death experience in this inspirational drama. She starts life over as an ordained minister. Joe Spano, Dan Lauria, Robin Gammell, Lorraine Toussaint and Gavin Harrison co-star. (Saturdays at 8 p.m. on NBC, beginning April 1.)

* “In the House”: Choreographer, TV director and former “Fame” star Debbie Allen returns to acting as a once-rich but just divorced mother who must now enter the work force. To make ends meet, she rents out the home of an injured NFL star, played by rapper LL Cool J, who moves into the garage to meet his own expenses. (Mondays at 8:30 p.m. on NBC, beginning April 3.)

* “Take Two”: Two friends played by comedians of two different races is the formula for this sitcom, created by the team behind “Home Improvement.” Dave Chapelle and Jim Breuer star as the black and white buddies who run a modest film and video production company in Detroit. (Premiere date not yet announced by ABC.)