AT&T Answering Machine model 1720. Seems to work for about 30 seconds when connected to power source then stops working. The message number is 0 and none of the other buttons respond when pressed. I unplug it for a minute or two, then plug it back in, wait for about 15 seconds, it beeps, I can press the clock button and it speaks the day and time, but after about 30 seconds it stops. I prefer this machine to any electronic voice mail. Can this machine be fixed?

You will need to go to the AT&T product support website and if the manual exists online it will be there in pdf form.

To play back messages remotely, first you'll need to have set up your two-digit security code (PIN). You can download a copy of the manual here which gives all the details. Once you've done that, here's how to use the system:

1) Call your telephone number and wait for the system to answer. If the answering system is off, it will answer after about 10 rings and sounds a series of beeps.
2) During the greeting message (or a series of beeps when the answering system is off), press 0 and enter your PIN code within 2 seconds. The answering system announces the current time and the number of messages stored in memory. You hear "To play incoming messages, press zero-two. For help, press one-zero." You will hear a beep.
3) Enter a command within 15 seconds. Each command thereafter must be entered within 2 seconds. These are the available commands:

• 0 then 1 Repeat a Message*
• 0 then 2 Playing incoming Messages
• 0 then 3 Skipping a Message
• 0 then 4 Deleting a Message
• 0 then 5 Stop Operation
• 0 then 6 Answering System On
• 0 then 7 Memo Record/Stop**
• 0 then 8 Greeting Message Record/Stop**
• 0 then 9 Answer System Off
• 1 then 0 Help

* For the Repeat a Message function, press 0 then 1 within about four seconds to repeat the previous message, or press 0 then 1 after about four seconds to repeat the current message.

**For the Memo Record and Greeting Message Record function, the first time you enter the corresponding command, it starts the Recording function. If you want to stop the recording, press 0 then 7, 8 or 5.

4) After the command has finished, you hear intermittent beeps indicating that the system is in the command waiting mode. You may enter another command at this time from the chart above.
5) Hang up when you're done.

Remote Message Retrieval
You can operate your answering system from a remote location using any touch-tone
telephone or the handset.
Remote access away from home
You can check, play, or delete messages, even record a new greeting message when
you are away from home. Additionally, you can turn On or Off your answering system
from a remote location.
Remote access:
1) Call your telephone number and wait for the system to answer. If the answering
system is off, it will answer after about 10 rings and sounds a series of beeps.
2) During the greeting message (or a series of beeps when the answering system is off),
press 0 and enter your PIN code within 2 seconds (see "Setting a PIN Code" in your owners manual.
3) The answering system announces the current time and the number of messages stored
in memory. You hear "To play incoming messages, press zero-two. For help, press onezero".
You will hear a beep.

4) Enter a command within 15 seconds, each command there after must be entered
within 2 seconds. You may select a command from the following chart:
For your convenience
a remote operation
card is provided for
you to use while
away from home, it can be found in the back of your owners manual.
Command Function
0 then 6 Answering System On
0 then 7 Memo Record/Stop **
0 then 8 Greeting Message Record/Stop **
0 then 9 Answer System Off
1 then 0 Help Guidance
Command Function
0 then 1 Repeat a Message*
0 then 2 Playing incoming Messages
0 then 3 Skipping a Message
0 then 4 Deleting a Message
0 then 5 Stop Operation
* For Repeat a Message function, press 0 then 1 within about four seconds to
repeat the previous message, or press 0 then 1 after about four seconds to repeat
the current message.
** For Memo Record and Greeting Message Record function, the first time you enter
the corresponding command, it starts the Recording function. If you want to stop
the recording, press 0 then 7 or 8.

5) After the command has finished, you hear intermittent beeps indicating that the
system is in the command waiting mode. You may enter another command at this
time from the chart above.

6) When you are finished, hang up to exit the system. The answering system
automatically returns to standby.
Your machine automatically has a PIN set of 80.
If you are trying to use remote access from a cellular phone and having trouble: Try changing your tone length on your cell phone to long.

Connect the telephone line of the answering machine from the series connection of the facts machine
.Now set the number of rings for the answering machine to activate to the maximum.{This is found on the side of the machine as a reed switch.}
Now when the calls comes in there is enough time for you to allow it to the answering machine or to attend a call or to set it to facts if a document is comming.While you are away you have to decide the priority needed for either facts or answering as it is a commonline. If answering machine has to work set the facts to telephone mode.If facts has to work set it to facts as the machine will activate before the answering machine.

Here are the instructions you need to follow:

If you want to be able to play your messages from a remote location, you need to enter a two-digit Personal Identification Number (PIN) code (01-99).
To select a PIN, perform the following steps:
1) With the phone in standby, press [menu/clock] twice.
The system announces "Security code," and the current PIN code is announced as it is displayed on the base.
Then the system announces the instructions for setting the PIN code.
2) Press [volume/select/ ] or [volume/select/ ] until the desired number appears.
3) Press [set] to select the PIN code. You hear a confirmation tone, then the announcement "Security code" followed by the new PIN code is announced. After a few seconds, the system announces "To set ring time, press menu again."
Note: The PIN code is set to "80" at the factory.

Remote Operation
When you are away from home, you can operate your answering machine with any touch-tone telephone. Use this function to check for recorded messages, to play or delete messages, even record a new greeting message.
1) Call your telephone number.
2) During the greeting message, press [0] and enter your PIN code
3) The answering machine announces the current time and the number of messages stored in memory. Then you hear "To play incoming message, press zero two. For help, press one zero."
4) You may continue to listen to the voice prompts, or you may select a command from the following chart:
Command Function Command Function
[0] then [1] Repeat a Message [0] then [6] Answering Machine On
[0] then [2] Play Incoming Messages [0] then [7] Memo Record/Stop*
[0] then [3] Skip a Message [0] then [8] Greeting Message Record/Stop*
[0] then [4] Delete a Message [0] then [9] Answering Machine Off
[0] then [5] Stop Operation [1] then [0] Voice Prompts
* For Memo Record and Greeting Message Record functions, the first time you enter the corresponding command, it
starts the Recording function. If you want to stop the recording, enter the command again.
Note: Once you enter the remote access menu, you must enter a command within 15 seconds, or the
answering machine automatically hangs up and returns to standby.
5) After all of the voice prompts have been played, you hear intermittent beeps indicating that the system is in the
command waiting mode. You may enter another command at this time from the chart.
6) When you are finished, hang up to exit the system. The answering machine automatically returns to standby.

Turn on the Answering Machine Remotely
If you have forgotten to turn on your answering machine, you can turn it on remotely from any touch-tone telephone.
1) Call your telephone number.
2) Wait ten rings until the system answers. You hear intermittent beeps.
3) Press [0] and then enter your PIN code. The answering machine announces the number of messages stored in memory. You hear "To play incoming message, press zero two. For help, press one zero."
4) Press [0] then [6] to turn the answering machine On. You hear the outgoing message and a confirmation tone.
5) Hang up the phone; subsequent calls will be answered by the system.

Since I have not idea what exact model you have this may or may not work... I hope it helps, as it is for a Uniden answering service phone.

Remotely Operating Your Answering Machine

Note: The answering machine will only playback messages for four minutes and then it returns to the command waiting mode.

To continue playing your messages, press [#] then [2] again within 15 seconds.
To operate from a remote location, use any touch-tone telephone and follow these steps:
1.) Call your telephone number and wait for the answering machine to answer
2.) During the greeting message, press [#] and enter your PIN code within 2 seconds;

How to enter a PIN
To play your messages from a remote location, you will need to enter a two-digit Personal Identification Number (PIN) or PIN Code.
Press the MENU soft key. Select the ANSW. SETUP menu, and then the SECURITY CODE submenu.
Enter a two-digit security code (00-99) using the number keypad [0-9].
Press the OK soft. You will hear a confirmation tone.

The answering machine announces the current time and the number of messages stored in memory.
You hear "To play incoming messages, press pound-two. For help, press pound-zero." You will hear a beep.
Enter a remote command within 15 seconds, each command there after must be entered within 2 seconds. You may select a command from the following:

# then 1 Repeat a Message
# then 2 Playback Messages
# then 3 Skipping a Message
# then 4 Deleting a Message
# then 5 Stop Operation
* # then 6 Answering Machine On
# then 7 Memo Record/Stop**
# then 8 Greeting Record/Stop**
# then 9 Answer Machine Off
# then 0 Help Guidance

this instruction may help you , if not a model number could help , but try these instructions . thanks

To operate from a remote location, use any touch-tone telephone, and follow these steps:
Call your telephone number and wait for the answering machine to answer. If the answering machine is off, it will answer after about 10 rings and series of beeping sounds.
During the greeting message (or a series of beeps when the answering machine is off), press [0] and enter your PIN code within 2 seconds (see "Setting a Security Code or Personal Identification Number (PIN)" on page 57).
The answering machine announces the current time and the number of messages stored in memory. You hear "To play incoming messages, press zero-two. For help, press one-zero." You will hear a beep.
Enter a remote command within 15 seconds, each command there after must be entered within 2 seconds. You may select a command from the following chart:
Remote Commands

Command 0 then 1
Repeat a Message*
Command 0 then 6
Answering Machine On
Command 0 then 2
Playback Messages
Command 0 then 7
Memo Record/Stop**
Command 0 then 3
Skipping a Message
Command 0 then 8
Greeting Record/Stop**
Command 0 then 4
Deleting a Message
Command 0 then 9
Answer Machine Off
Command 0 then 5
Stop Operation
Command 1 then 0
Help Guidance

we can get a link to your manual if we had model number

Try this...
See if this works for you.

Remote Operation
When you are away from home, you can operate your answering system with any
touch-tone telephone.Use this function to check for recorded messages, to play or
delete messages, even record a new greeting message.
1) Call your telephone number.
2) During the greeting message, press 0 and enter your PIN code.
3) The answering system announces the current time and the number of messages
stored in memory. Then you hear "To play incoming message, press zero two.
For help, press one zero."
4) You may continue to listen to the voice prompts, or you may select a command
from the following chart:

Command Function
0 then 1 Repeat a Message
0 then 2 Play Incoming Messages
0 then 3 Skip a Message
0 then 4 Delete a Message
0 then 5 Stop Operation
0 then 6 Answering System On
0 then 7 Memo Record/Stop*
0 then 8 Greeting Message Record/Stop*
0 then 9 Answering System Off
1 then 0 Voice Prompts

If you forgot to turn on answering system the directions for that are here:

Turn on the Answering System Remotely
If you have forgotten to turn on your answering system, you can turn it on remotely
from any touch-tone telephone.
1) Call your telephone number.
2) Wait ten rings until the system answers. You hear intermittent beeps.
3) Press 0 and then enter your PIN code. The answering system announces the
number of messages stored in memory. You hear "To play incoming message,
press zero two. For help, press one zero."
4) Press 0 then 6 to turn the answering system On. You hear the outgoing message
and a confirmation tone.
5) Hang up the phone; subsequent calls will be answered by the system.

Here is a link to the pdf format owners manual from Uniden for this phone:

http://www.uniden.com/pdf/TRU8885om.pdf

Remote Operation
You can check, play, or delete messages, even record a new greeting message from a
remote location (when you are away from home, or from another room using a
handset). Additionally, you can turn on or off your answering system remotely.
Remote access away from home
You can operate your answering system from a remote location using any touchtone
telephone.
1) Call your telephone number and wait for the system to answer. If the answering
system is off, it will answer after about 10 rings and sounds a series of beeps.
2) During the greeting message (or a series of beeps when the answering system is
off), press 0 and enter your PIN code within 2 seconds (see "Setting a PIN Code"
on page 25).
3) The answering system announces the current time and the number of messages
stored in memory. You hear "To play incoming messages, press zero-two. For
help, press one-zero." You will hear a beep.
4) Enter a command within 15 seconds, each command there after must be entered
within 2 seconds. You may select a command from the following chart:
* For the Repeat a Message function, press 0 then 1 within about four seconds to
repeat the previous message, or press 0 then 1 after about four seconds to repeat
the current message.
**For the Memo Record and Greeting Message Record functions, the first time you
enter the corresponding command, the phone starts recording. If you want to
stop the recording, press 0 then 7, 8 or 5.
5) After the command has finished, you hear intermittent beeps indicating that the
system is in the command waiting mode. You may enter another command at this
time from the chart above.
6) When you are finished, hang up to exit the system. The answering system
automatically returns to standby.

Command Function Command Function
0 then 1 Repeat a Message* 0 then 6 Answering System On
0 then 2 Playing incoming Messages 0 then 7 Memo Record/Stop**
0 then 3 Skipping a Message 0 then 8 Greeting Message Record/Stop**
0 then 4 Deleting a Message 0 then 9 Answer System Off
0 then 5 Stop Operation 1 then 0 Help