GenRad Inc finds that even when your credit rating is down in the Cs, which casts biq question marks over over your ability to survive in your present form, things can get still blacker: Standard & Poor’s Corp said it downgraded to CCC from CCC-plus GenRad Inc’s $48m of subordinated debt and said its rating outlook was still negative. The implied senior debt rating is B-minus. The New York rating agency said very weak demand and aggressive pricing for mature printed circuit board testers have caused annual revenue declines at GenRad since 1988.Limited order backlogs impede efforts to improvemanufacturing efficiency at the company and while GenRad’s stringent cost constraints intended to restore profitability at the $30m to $35m quarterly revenue range have not yet been successful, losses and realignment charges have wiped out the company’s equity base. Some revenue and earnings improvement at GenRad is expected to begin in 1993 from two major new contracts, but the agency sees GenRad’s inherent profitability to remaining slim.