Apple's manufacturing choice for the iPhone 6 and iPhone 6 Plus brought it to court in a class-action lawsuit, with three additional law firms recently joining the legal action.

The so-called "Touch Disease" affects a large number of Apple iPhone 6 and Apple iPhone 6 Plus models, and users can easily identify it. The most common symptoms are a flickering gray bar going across the screen's width (usually at the top) and the screen becomes unresponsive to input.

During the summer, Apple was called to court by a class-action lawsuit, as the main plaintiff claimed that the affected iPhone models have a design flaw that is behind the aforementioned issues.

According to Jason Villmer, who owns a phone repair shop, the defect turns every iPhone 6 and iPhone 6 Plus into "a ticking time bomb." He points out that, in his experience, no iPhone 6 or iPhone 6 Plus is off the hook when it comes to developing the disease.

Experts looked into the matter and found that the touch screen controller chips are to blame. Sometime after the phone is regularly used, the chips lose contact with the motherboard, causing them to stop working. It may be that the bendy nature of the phone models contributes to the vulnerability, as more rigid phones, namely the iPhone 6s, do not face the problem.

Hardware specialists claim that the issue could have been easily fixed by simply adding an extra metal plate.

On one hand, Apple asks that those who purchased out-of-warranty iPhones would shell out as much as $329 for a replacement. On the other hand, customers who did go through the exchange are facing the identical problem only days or weeks after getting their new device.

Apple refused to publicly address the issue, despite insight from former or current Apple Geniuses who confirmed the existence of the "Touch Disease" and the company's knowledge of the problem.

Recently, three more law firms joined the class-action lawsuit, adding several plaintiffs to the case. At the time of the writing, there are as many as 9,539 members of the class who saw the "Touch Disease" hit their smartphones.

Should you want to take a peek into the 51 pages of the updated complaints, here's the link for your reading pleasure.

Those who own iPhone 6 or iPhone Plus devices and notice one of the problems stated above might want to contact the firms that are handling the lawsuit.

Among the accusations against Apple are breach of implied warranty, negligent misrepresentation, unjust enrichment and other consumer act violations.