Help from graph experts

I have a 12 chirp at the console and a 10
In the front. I'm selling my boat so wanted to delet my waypoints. I turned on the 12 and manually deleted all
the points. Then i turned on the 10 in the front and it started clicking, ticking and I assumed it was deleting all points. Ecause their linked. When it finished the screen is blank. I can see enough light to know it has power and when you first turn it on and push a button it will beep like normal but only once, then all the buttons are dead. Thanks in advance.

I would remove the cables and take them out of the bracket. Plug in only the power and transducer. Power the unit up. See what happens. You can press the power button once to get teh screen choice of color and lighting to come up. Make sure the screen color isn't changed to black and the lighting is set to 10.

Linking them does not transfer GPS data to another unit or control the other unit's GPS data, just displays them in a different color.

The best way to clear the unit's memory is Format Nav Directories. Everything is gone at once.