In a class action complaint filed this week, plaintiffs allege that the microphones in their Pixel and Pixel XL phones were defective from the start, and that Google knowingly sold defective phones amid widespread complaints immediately after launch. The lawsuit also claims that some warranty replacement phones continued to have problems, though neither of the named plaintiffs in the lawsuit had their phones repaired within Google’s standard warranty period.

Google acknowledged the Pixel phones’ microphone issues in March 2017. An employee on Google’s support forums attributed the problems to “a hairline crack in the solder connection on the audio codec,” and said the problem can come and go depending on the temperature of the phone or the way it’s being held. “This is especially frustrating as a user because, just when you think you’ve got it fixed, the problem randomly comes back,” the Google employee wrote. This might explain why one of the plaintiffs didn’t seek a repair until more than a year after buying the phone.

Hardware defects have been a recurring theme for Google’s Pixel phones, which have otherwise won praise for their excellent cameras and unadulterated Android software. Pixel 2 and XL2 users have complained of burn-in and black image smudging with the phones’ OLED displays, along with muted microphone problems. Girard Gibbs LLP, the same law firm that’s suing Google over the original Pixel, is looking into a class action suit over the second-generation model as well.

In response to Pixel 2 complaints, Google extended customers’ standard warranties to two years. No such courtesy exists for original Pixel owners.

Google declined to comment.