Last month a TV station in Los Angeles went off the air for equipment maintenance. Yet the overnight Nielsen ratings suggested that more people were watching its blank screen than the programming on a number of other local stations. That lead to renewed cries that the Nielsens are screwy. Well, in the television business, ratings are a lot like the weather: Everybody squawks about them, but no one does anything about them. This week's episode of Nova, "Can You Believe TV Ratings?" on PBS (Tues., Feb. 18, 8 P.M. ET), suggests that may be changing. The networks, Nielsen's loudest critics, are interested in a photosensitive device, now being developed by several audience-research companies, that will be mounted on top of the TV and will sweep the room periodically to monitor who is really sitting in front of the set. In other words, very soon, when you're watching TV, the TV may be watching you.

CBS (Fridays, 9 P.M. ET)

D+

What do you get when you put a likable cast in a ludicrous premise? A show that you hate yourself for watching. Series vagabond Jack Scalia plays Nico Bonetti, an Italian cop from Brooklyn transplanted to a flaky beach precinct in California. He's teamed with a uniformed rookie (Mariska Hargitay, the daughter of bodybuilder Mickey Hargitay and bombshell Jayne Mansfield) and a French mastiff named Tequila (playing himself).

The gimmick? We can hear the dog's every thought. The mutt's stale street jive ("Get down with your bad self, home slice") is provided by Brad Sanders, the guy who, as Clarence, does a daily plot update of The Young and the Restless on the radio. Rounding out the cast is Saturday Night Live alum Charles Rocket as the police captain, a smoothie with an earring and a subscription to Variety.

The show wouldn't be so painful to watch if the criminal cases assigned to this crew weren't so inane and if the writers didn't have to work so hard to get Tequila involved in solving them.

Each episode, though, does contain little grace moments when the camera observes the characters being themselves alone. We see Bonetti moodily playing the piano, Rocket sweating over a screenplay and Rodney Kageyama, who has a recurring role as a Japanese gardener, dancing ecstatically in drag. These unexpected vignettes, presented like music videos, suggest a creativity utterly lacking in the rest of the hour.

NBC (Sun., Feb. 16, 9 P.M. ET)

B+

A young single mother (Sarah Jessica Parker of L.A. Story) with a history of severe manic depression moves back to her Iowa hometown, relapses and is hospitalized. Her five small children are placed with foster parents (John Dennis Johnston and a brunet Sally Struthers) who fight to keep the children even after Parker is eventually discharged.

The film, based on actual events, begins to lose its impact once the custody battle between the birth and foster parents is joined, but the first hour is powerful and well acted. Parker delivers a moving performance as a disturbed woman swamped In poverty, violence and her own emotional volatility. Lexi Randall is also good as the 11-year-old, eldest child who has to function as a surrogate parent, even reminding her mom about birth-control pills when Parker stumbles home with another low-life bar pickup.

The biggest surprise is Johnston, who after a career mainly playing menacing B-movie thugs, brings coal warmth and substance to the role of the gentle farmer and foster dad.

NBC (Man., Feb. 17, 9 P.M. ET)

B+

Like last year's And the Sea Will Tell, this is a movie based on a book rewritten by Vincent (Helter Skelter) Bugliosi detailing the former prosecutor's legal prowess. Arliss Howard plays Bugliosi in 1967, as a hotshot young assistant district attorney trying to bring a case based on circumstantial evidence against a dermis and deadly former cop (Treat Williams) involved in murder-for-insurance-money schemes.

This would qualify as merely an elaborate ego boost for Bugliosi, except for the strikingly stylish direction by Yves (Memphis) Simoneau. In fact, the movie is so visually creative and seamless that it looks absolutely cinematic, which is exceedingly rare in TV projects, where bland exposition usually rules. One other factor makes this movie Cineplex-suitable: It's unusually violent.

>RECENTLY SATURDAY NIGHT LIVES executive producer, Lorne Michaels, appeared in a skit, telling guest host Steve Martin that "the show's been on automatic pilot for years."

Sad but true, Lornemeister. Most of the time the east flounders through interminable sketches with undeveloped premises that just lie there like the oldest seal at the zoo: for instance, Julia Sweeney's ongoing no-joke routine as the androgynous Pal or guest host Christian Slater's skit about a guy trying to order Buffalo chicken wings despite the proprietor's warning that they are really, really hot. Last one out of the room, turn off the set.

Martin may have inadvertently hit the heart of the problem during his appearance. He introduced Adam Sandler and Chris Farley as the Energy Brothers, who proceeded to do nothing more than jump and twitch around the stage. "You have to keep reminding yourself," said Martin, "they have no material—they're that good." No, they're not. The show's best troupe—John Belushi, Bill Murray et al.—may have been able to get over on charisma alone. But lacking decent material, the current cast is dying a thousand deaths every Saturday night live.