My phone won't let me dial out. I have a dial tone, but it's like I'm not pressing anything. I think I've accidentally hit something that switched it away from tone dialing, but can't find out how to switch it back. It's worked fine for several years.

is the phone base plugged into the phone socket correctly?

Unplug the phone from both the line and power adapter. Let it set for at least a couple of minutes. You may have activated call forwarding - all accidentally, if that happened the problem will be in the electronic exchange, not the phone. Find out what the "cancel call forwarding" code is for your system....

Intercom button/s provide dial tone when they are pressed. They are required to call other phones on your system.
Sounds like your button is stuck or issue with the motherboard.

Some units if the battery is not fully charged or any ac adaptor for another phone also connected is not plugged in you will now have no dial tone.

someone else has the same frequency,why do you think he got rid of it?

Resetting the voice message waiting indicator
When you receive a new voice mail message, the new message LED on the top of the handset flashes. In the event your message waiting light gets out of sync with your phone company's
voice messaging system, you can manually reset it back to the "No messages waiting" state.
1. Press and hold FiND on the base for five seconds.
Note: The handsets connected to the base will start to beep, however, keep pressing for five seconds.
2. A beep sounds and the message alert tone is reset.
Changing the dial mode
Your phone can communicate with the telephone network in two different ways: tone dialing or pulse dialing. These days, most base networks use a method called tone dialing, so your phone comes programmed for tone dialing. If your phone company uses pulse dialing, you will need to change your phone's dial mode. If you don't get a dial tone or can't connect to the telephone network, please follow the steps below to modify your phone's settings:
1. Press MENU/SELECT.
2. Select the Global Setup menu, and then the Dial Mode submenu.
3. Scroll to highlight Pulse.
4. Press MENU/SELECT. You will hear a confirmation tone.
If you ever need to change the dial mode back to tone dialing, follow the same procedure, but select Tone in step 3.

Finally for future ease of use, here is a link to the user manual were I copied the above information from:

http://www.uniden.com/content/ebiz/uniden/resources/ownersmanuals/DECT1580-3om.pdf

Hi,

Try reset the phone in question, Turn off the phone, remove the AC adapter, press and hold the page/call button that is on the phone and plug back your Ac adapter, see if this fix the problem.

in GE:

TONE/PULSE DIALING
This adjustment allows you to select tone (touch-tone) or pulse (rotary) mode dialing. The phone is pre-set for
touch-tone use. To set to tone or pulse dialing:
1. Press and hold the program button for two seconds. You will hear a beep.
2. Press the *tone button to select Tone Dialing or press #pause to select Pulse Dialing.
3. Press the program button again. You will hear a confirmation tone.

press menu then globel setup and then press dial mode then change the the dial tone you want

Lisa, If the 900MHZ phone is Model 26928M programming for rotary dial usually goes like below, can't hurt to try on any model. TONE/PULSE DIALING This adjustment allows you to select tone (touch-tone) or pulse (rotary) mode dialing. The phone is pre-set for touch-tone use. To set to tone or pulse dialing: 1. Press and hold the program button for two seconds. You will hear a beep. 2. Press the *tone button to select Tone Dialing or press #pause to select Pulse Dialing. 3. Press the program button again. You will hear a confirmation tone.