I you have no display on your CSC1000 amplified telephone, try the following:
If your screen is lit but there is no writing on it (no letters or numbers appear) and you can still use the phone to make calls, you may have the wrong adapter plugged into the phone. The correct adapter for the CSC1000 will have a 7.5 volt and 500 mAh output. If you are using an adapter with a different voltage or amperage the phone will not function properly.
If the screen does not light up at all and there are no letters or numbers on the screen, then the AC adapter may not be plugged into the back of the phone. Check to make sure the adapter is plugged firmly into the back of the phone and also plugged into a working electrical outlet.