The fax machine is in sleep mode

Step by step information at the link below.
Brother Fax T96
The F/T Mode is used to allow the fax machine and the telephones to share the same telephone line. When a call comes in, the fax machine and all extension telephones on that line will ring according to the number of rings you have set for the Ring Delay.
When the Ring Delay is completed, the fax machine will answer the call and determine if it is a fax call or a telephone (voice) call.
The fax machine can determine this by the signal it is receiving on the telephone line. If someone is sending a fax automatically , the sending fax machine will transmit a fax tone (a series of beeps every 3 seconds).
If your fax machine hears these tones, it will receive the fax.

If the fax machine does not hear any fax tones, it assumes it is a telephone (voice) call and will begin ringing the F/T ring tones (double ring) for the length of time you selected for the F/T Ring Time. These tones will only ring on the fax machine's handset (extension or external phones will not ring). At the end of the F/T ring time the fax machine will go into the receive mode in order to receive a manual fax.
(If the call was a voice call and was not answered, the caller will hear the fax receive tones also).

• If you answer the call before the fax machine(during the ring delay period) and determine it is a fax, you can transfer the fax to the fax machine for receiving.
  
  
• If you answer the call on an "extension" phone and hear a beep every 3 seconds (automatic fax) or silence (manual fax), press *51 or *91 for New Zealand (remote activation code) on the telephone keypad, wait to hear the fax machine turn on (chirping sounds) and then hang up.
  
  
• If you answer on the handset of the fax machine and hear a beep every 3 seconds or silence, press the Fax Start or Start/Copy key on the control panel of the fax machine and then hang up the handset.
  
  
• If you answer a call on an "extension" phone during the F/T Ring Time, you will hear the F/T ring tones.
  To release the call from the fax machine, press #51 or #91 for New Zealand (remote deactivation code) on the telephone keypad and you can speak to the calling party.
  
  
• If you pick up the handset of the fax machine during the F/T ring time, you may talk to the calling party immediately.

Firstly, you will need to get a 2nd ringtone from your phone provider. Most of them will provide a designated "fax ring" (not a new number) for little or no cost.

In DRPD mode, you can receive a call using the Distinctive Ring Pattern Detection (DRPD) feature. “Distinctive Ring” is a telephone company service which enables a user to use a single telephone line to answer several different services.

Using the Distinctive Ring Pattern Detection feature, your fax machine can “learn” the ring pattern you designate to be answered by the fax machine. Unless you change it, this ringing pattern will continue to be recognized and answered as a fax call, and all other ringing patterns will be forwarded to the
extension telephone or answering machine plugged into the EXT. jack. You can easily suspend or change Distinctive Ring
Pattern Detection at any time.

Before using the Distinctive Ring Pattern Detection option, Distinctive Ring service must be installed on your telephone line by the telephone company. To set up Distinctive Ring Pattern Detection, you will need access to another telephone or someone available to dial your fax number from outside (a cell phone will do!).

To set up the DRPD mode:

1 Press Menu until “Fax Setup” appears on the top line of the display.
2 Press the scroll button ( or ) until you see “Receive Mode” on the bottom line and press Enter.
3 Press the scroll button ( or ) until you see “DRPD Mode” on the bottom line and press Enter.
4 When “Set” displays on the bottom line, press Enter.
“Waiting Ring” appears on the display.
5 Call your fax number from another telephone. It is not necessary to place the call from a fax machine.
6 When your machine begins to ring, do not answer the call.
The machine requires several rings to learn the pattern.
When the machine completes learning, the LCD displays “End DRPD Setup”.
If the DRPD setup fails, “DRPD Ring Error” appears. Press Enter when “DRPD Mode” displays and retry from step 3.
7 To return to Standby mode, press Stop/Clear.
When the DRPD feature is set up, the DRPD option is available in the Receive Mode menu.

To receive faxes in the DRPD mode,
you need to set the menu to DRPD;

NOTES:
• DRPD must be set up again if you re-assign your fax number, or connect the machine to another telephone line.

• After DRPD has been set up, call your fax number again to verify that the machine answers with a fax tone. Then have
a call placed to a different number assigned to that same line to be sure the call is forwarded to the extension telephone or answering machine plugged into the EXT. jack.

• In Tel mode, you can receive a fax by picking up the handset of the extension phone and then pressing the remote receive code Alternatively, you can press On Hook
Dial (you can hear a fax tone from the remote machine) and then press Start on the control panel of your machine.
• In the Fax mode, the machine answers an
incoming call and immediately goes into fax
reception mode.
• In Ans/Fax mode, the answering machine answers an incoming call, and the caller can leave a message on the answering machine. If the fax machine senses a fax tone on the line, the call automatically switches to Fax mode.
• In DRPD mode, you can receive a call using the Distinctive Ring Pattern Detection (DRPD) feature. This option is available only when you set up the DRPD Mode.

The full user manual for your machine is located here

Hope that is of help to you :)

My Mode was wrong. I switched it to telephone and fax (instead of manual). Then i set the ring to pick up on the third ring. now i dont have to be here to press start everytime a fax comes. I found all the information by searching for the manual on line it is under "Basic fax settings"

The machine is set with the sleep mode as a default. The fax part can be changed to recieve a fax by pressing the fax mode button. Press it until it says Fax only, not F/T. F/T means Fax/Telephone. This mode would make it to where you have to pick up the reciever and press start when a fax comes in. The Fax only mode means it will pick up everytime a fax comes in automatically. Let me know if this was helpful. Please give my helping a rating. Thanks!

Receive Mode Settings Select from the following receive mode options to suit your needs. Once you've decided on which receive mode to use, follow the below instructions to set the receive mode using the operation panel. Receive Mode Setting

1. Press the <FAX> button to enter Fax mode.
   
2. Press <Menu>.
   
3. Press the right or left arrow button to select [Receive mode settings], then press the <OK> button.
   
4. Press the up or down arrow to select the receive mode that best suits your needs, then press <OK>.
   
   

Types of receive mode
Select the receive mode according to your needs.
Receive mode
Purpose
FAX/TEL AUTO SW When you want to receive faxes automatically as well as voice calls. FAX ONLY MODE When you want to receive only faxes automatically with your machine, or have a dedicated telephone line for FAX use only. DRPD When you have subscribed to a DRPD service with your telephone company. MANUAL MODE When you receive mainly voice calls and sometimes faxes, or want to receive faxes manually. ANS.MACHINE MODE When you want to receive voice messages on your answering machine and receive faxes automatically. FAX/TEL auto switch
FAX :
The machine does not ring but will receive the fax automatically. Voice call :
The phone attached to the machine will ring. Pick up the handset to answer the call. Note:

• Ring start timing and Telephone ring length can be specified in FAX/TEL auto switch in the Receive mode settings.
  
• If you want the telephone to ring when it receives a fax, connect a telephone to your machine and enable the Incoming ring settings in RX settings.
  
• The phone attached to the machine may not ring depending on the telephone type you are using.

FAX only
FAX * :
The telephone does not ring. The machine will receive the fax automatically. Voice call :
You will not be able to answer the call. * If you want the telephone to ring, connect the telephone to your machine and enable the Incoming ring settings in RX settings menu.


DRPD
FAX :
Your telephone line will ring according to the ring pattern you have chosen and receive the fax automatically. Voice call :
Your telephone line will ring according to the ring pattern you have chosen. Pick up the handset to answer the call. Note: Specify the FAX pattern in the DRPD: Set FAX ring pat. in RX settings menu.

Manual RX
FAX :
The telephone attached to the machine will ring. Pick up the handset and if you hear a beep tone, press the <Color> or <Black> button on the machine to receive the fax. Voice call :
The telephone attached to the machine will ring. Pick up the handset to answer the call. Note: If you are far from your machine, you can use the remote receiving function to receive faxes. Pick up the handset of the telephone connected to the machine and press 25 (the remote receiving ID).

Ans. machine connect
FAX :
First the answering machine connected to your machine will respond to an incoming call, and then the machine will receive faxes automatically. Voice call :
The answering machine connected to your machine will respond to an incoming call. Note:

• Set the answering machine to answer on the first or second ring.
  
• The entire message should be no longer than 15
  

Telephone wire goes to fax, out to answer machine, Important to set fax on answer machine mode and set the ring count to pick up AFTER the telephone answer machine. Set fax ring count to 5 rings, and answering machine to 3 or 4. When some one calls answer machine or you pick up first, then if no one will leave a msg. fax tones are different than voice tones, they are called CNG tones. Most new fax machine will sense this and if a fax will go to fax only. Ring count is the key. Also you could set fax up for maual mode and would not jump to anser machine or fax till you want.....good luck

The machine is probably set to "manual receive." Check the receive mode. In "Manual" mode the machine will ring until the start" button is pressed. Fax mode will allow the machine to receive faxes as will the "Auto" mode which will allow both faxes and telephone calls automatically.

Is tel line going into correct socket of fax? (Line not Ext.)

 

Is Fax set to auto answer or manual?

 

If you pick up line or press speaker button can you hear other fax sending if so press start and hang up you should receive fax, and you have just proven that machine is in manual receive mode!

 

I think you will find it  will wake from sleep automaticly if setup correctly.

The sleep mode is only a power save mode. You may not have the machine in the correct fax receive mode. If the machine is on a line by itself it needs to be set to fax only, if line is shared with a telephone it needs to be in fax/telephone, if you share the machine with an answering machine it needs to be in TAD mode, and so forth. Each time you press the MODE key it will change the receive mode. Most people hit this key by mistake and change the MODE and the unit will not pick up calls. Press the MODE key until you are in the correct mode. To make sure the machine will print, press reports and then the 1, this will print a help list. If the help list prints you know that the machine works. Then check to make sure the machine is in the correct fax receive mode.

TAD is Telephone Answering Device. TAD mode is the only mode that can be used with an external telephone answering device (unless you are using a distinctive ring number for receiving faxes). Your telephone answering device must be connected to the jack on the fax machine (labeled "EXT" for USA). When someone dials your telephone/fax number (to send a fax or to speak to you), all the telephones (including the FAX) will ring according to the number of rings you set on the TAD. The Ring Delay setting is not recognized in the TAD mode. If you do not answer the call, the TAD will answer. As your outgoing message is playing, the Fax is in the background, silently listening for fax tones. If the FAX hears fax tones, it will automatically go into the receive mode. If the FAX does not hear fax tones, it remains silent, allowing the caller to leave a message. The above information is correct for a Brother fax machine. Is your fax automatically picking up the call or do you have to push a panel button to start the receive fax process? Perhaps the fax is already "in" your fax machine's memory and only needs a manual printout. Check the fax call log.