A number of the sitcom's stars, including Marion Ross, Anson Williams, Don Most, and Erin Moran, filed a $10 million (£6.3 million) lawsuit earlier this year (11), claiming CBS chiefs owed them money from sales of Happy Days-themed merchandise which features their images.
They were subsequently handed cheques with values ranging from $6,000 (£3,750) to $6,500 (£4,063), but vowed to press ahead with their case.
The group suffered a setback on Wednesday (19Oct11) when Los Angeles Superior Court Judge Elizabeth Allen White ruled in favour of CBS on the fraud claim.
The case will now proceed only with a breach of contract suit and the actors cannot receive punitive damages at the 2012 trial, according to CNN.
The group's lawyer, Jon Pfeiffer, says, "We intend to press forward with the lawsuit. If we can't punish the defendants, we certainly intend to expose their practices."
The series ran between 1974 and 1984.