Jurors failed to reach a decision and will return for a third day of deliberations to determine how much Samsung Electronics owes Apple for copying key features of the iPhone and iPad.
A previous jury found Samsung guilty of infringing several Apple patents in making and marketing 26 devices, and it ordered Samsung to pay $1.05 billion. But
US District Judge Lucy Koh tossed out $450 million of those damages and ordered the new jury to recalculate damages for 13 of the devices.
Apple is demanding $380 million. Samsung says it only owes $52 million.
The judge on Wednesday also refused Samsung's second request in as many days to halt the trial. The latest request was made after patent regulators questioned the validity of one of Apple's patents that Samsung was found to have infringed.
The US Patent and Trademark Office was "re-examining" Apple's patents for the pinch-to-zoom function on its phones and tablets. Apple has said it is the most commercially valuable of the three software patents at issue in the trial.
The office said Wednesday that Apple's arguments in support of the patent "are not persuasive." The office didn't invalidate the patent, but it ordered Apple to submit more evidence to support it.
Even if the patent office invalidates the patent, it remains valid through the long appeals process that could reach the US Supreme Court.
The San Jose federal courtroom is a 15-minute drive from Apple Inc.'s Cupertino headquarters, and several prospective jurors were dismissed because of their ties to the company.
Lawyers for South Korean-based Samsung Electronics Co. complained to the judge Tuesday that when Apple attorney Harold McIhenny told the jury that US television makers were driven out of business for failing to protect their intellectual property, it was an unfair attempt to inflame jurors' prejudices.
Judge Koh denied Samsung's demand for a mistrial, but she did call jurors back from deliberations to reread an instruction ordering them to put aside their dislikes and biases in deciding the case.
The two companies are locked in legal battles around the globe for supremacy in the more than $300 billion smartphone market.