How to Fix the 'Line in Use' Message on Panasonic KX-TG6641 Phones?

When your Panasonic `KX-TG6641` phone system displays a "Line in Use" message, it often indicates that another handset is actively using the line, or perhaps one of the handsets hasn't been properly hung up. To troubleshoot this issue, start by disconnecting all phones connected to the line and try plugging in a different phone to see if the problem persists. It's also a good idea to check any connections and microfilters you might have, as well as testing each socket individually if you have multiple ones. If you're using a broadband line, unplugging your computer and router from the phone line can help isolate the issue. If you still see the same message after trying a different phone, it might indicate a problem with your line itself, and contacting your service provider would be the next step. However, if the line works fine with another phone, the issue could be with your original unit. In that case, resetting the device may help. If you find that after unplugging all other phones and using just one, you do get a dial tone, that’s a good sign. If you don’t, try unplugging the base unit for about a minute before plugging it back in and checking for a dial tone again. This can often resolve minor glitches.