Fax machine won't receive without pick up phone receiver.

Check video for 'fax receive set up' in similar model:


Manual receive: In coming call receives like telephone
Fax/tele: Incoming call rings like telephone if its not fax, if incoming is fax it will entered in fax mode automatically
Automatic: Incoming call converts in fax mode after ring count ends( ring to answer option also avail in fax set up mode rage 1-6 rings)
Fax: Incoming calls straight away converts in to fax mode.( this option only for dedicated fax lines)
Set up your best option as per your requirement.

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.

Receiving a fax
Receiving a fax automatically
1 Make sure the printer is on and is connected to a working phone line.
2 Make sure that Auto Answer is on.
To check if Auto Answer is on:
a From the printer control panel, press (tool icon).
b Press the arrow buttons until Fax Setup appears, and then press ok.
c Press the arrow buttons until Ringing and Answering appears, and then press ok.
d Press again.
Check to see if Auto Answer is set to On.
e If Auto Answer is not set to on, press the arrow buttons until On appears, and then press to save the setting.
3 Set the number of times the telephone rings before the printer automatically receives faxes:
a Press the arrow buttons until Pick-up On appears, and then press ok.
b Press the arrow buttons until the setting that you want appears, and then press to save the setting.
When the number of rings you set is detected, the printer automatically receives the incoming fax.
Receiving a fax manually
1 Make sure the printer is on and is connected to a working telephone line.
2 Make sure that Auto Answer is off.
3 To receive the fax, press (green botton) or press * 9 * on the telephone after you answer it and hear fax tones.
4 Hang up the telephone.
The printer receives the fax.
Receiving a fax with an answering machine
1 Make sure that Auto Answer is on.
2 Make sure you have set the number of times the telephone rings before receiving a fax automatically.
When a telephone ring is detected, the answering machine picks up the call.
• If the printer detects a fax, it receives the fax and disconnects the answering machine.
• If the printer does not detect a fax, the answering machine receives the call.

3 Set the answering machine to answer incoming calls before the printer does.
For example, if you set the answering machine to answer calls after three rings, set the printer to answer calls
after five rings.
Forwarding faxes
Use the fax-forwarding feature if you are going to be away, but still want to receive your faxes. There are three
fax-forwarding values or settings:
• Off—(Default)
• Forward—The printer sends the fax to the designated fax number.
• Print & Forward—The printer prints the fax and then sends it to the designated fax number.
1 Make sure the printer is on and is connected to a working telephone line.
2 Press the arrow buttons until Fax Setup appears, and then press ok.
3 Press the arrow buttons until Ringing and Answering appears, and then press ok.
4 Press the arrow buttons until Fax Forward appears, and then press ok.
5 Press the arrow buttons until Forward or Print & Forward appears, and then press ok.
6 Enter the number to which you want to forward the fax, and then press ok.

Hi ...

There are situations when fax interrupts the telephone conversation. The possible cause of this issue is Remote RX feature on MP 780. There are 3 possible solutions to these problems which are listed below:

I) Change Remote RX ID on MP780

1. Confirm the <Fax> button light is lit. If the light is not lit, press the <Fax> button.
   
   
2. Press <Menu> button. [RECEIVE MODE] will appear on the display.
   
   
3. Press < (left arrow) or > (right arrow) to select [RX SETTINGS].
   
   
4. Press <OK>. [ECM RX] will appear.
   
   
5. Press the < (left arrow) or > (right arrow) to select [REMOTE RX].
   
   
6. Press <OK> twice. The current Remote RX ID number will appear.
   
   
7. Press < or > to select the desired Remote RX ID number. The options are from 00 to 99.
   
8. Alternatively, you can press the numeric keypad to select the number.
   
9. For example, to select [38], press <3> and then press <8>.
   
   
10. Press <OK>.
    
    
11. Press <Stop/Reset> to return to standby mode (date and receive mode will appear).

II) Turn off Remote RX on MP780

1. Confirm the <Fax> button light is lit. If the light is not lit, press the <Fax> button.
   
   
2. Press <Menu> button. [RECEIVE MODE] will appear on the display.
   
   
3. Press < (left arrow) or > (right arrow) to select [RX SETTINGS].
   
   
4. Press <OK>. [ECM RX] will appear.
   
   
5. Press the < (left arrow) or > (right arrow) to select [REMOTE RX].
   
   
6. Press <OK>. The current Remote RX option [ON] will appear.
   
   
7. Press < or > to select [OFF].
   
   
8. Press <OK>.
   
   
9. Press <Stop/Reset> to return to standby mode (date and receive mode will appear).

III) Choosing a receive mode MP780
If you want to receive only faxes automatically with your machine, or you have a dedicated telephone line for fax use only:

• Select [FAX ONLY MODE].
  
  When you receive a fax call: The machine will receive the fax automatically.
  When you receive a voice call: You will not be able to answer the call.

If you receive mainly voice calls and sometimes faxes, or you want to receive faxes manually:

• Select [MANUAL MODE].
  
  When you receive a fax call: The telephone will ring. Pick up the handset and if you hear a beep, press <Black> or <Color> on the machine to receive the fax.
  When you receive a voice call: The telephone will ring. Pick up the handset to answer the call.
  For remote receiving: If you are far from your machine, dial 25 (the remote receiving ID) on your telephone to receive faxes. (Telephone being used, such as a base station for a cordless phone, must be connected through the MP780 for the remote receiving function to work.)

If you want to receive voice messages on your answering machine and receive faxes automatically:

• Select [ANS.MACHINE MODE].
  
  When you receive a fax call: First the answering machine connected to your MP780 will respond to an incoming call, and then the MP780 will receive faxes automatically.
  When you receive a voice call: The answering machine connected to your MP780 will respond to an incoming call.

If you want to receive faxes automatically as well as voice calls:

• Select [FAX/TEL AUTO SW].
  
  When you receive a fax call: The machine will receive the fax automatically.
  When you receive a voice call: The machine will ring. Pick up the handset to answer the call.

If you have subscribed to a Distinctive Ring Pattern Detection (DRPD) Service with your telephone company (US only):

• Select [DRPD].
  
  When you receive a fax call: The machine will ring according to the ring pattern you have chosen and receive the fax automatically.
  When you receive a voice call: The machine will ring according to the ring pattern you have chosen. Pick up the handset to answer the call.

Dont' forget to vote if this helps .... Cheers :)

If you are receiving a fax and you pick up the telephone before the fax machine answers it, the fax will never be able to respond to the fax being received. I assume that is whats happening. If you have a phone connected directly to the fax machine and you pick it up from that phone, the fax machine should transfer to itself after 2 seconds when it recognizes that it is a fax machine.
If you are going to do it from anywhere else, you need to get a fax detector device connect it to the main phone jack, and have the fax machine go to the fax jack of the connector and the other phone in to the other lines, make sure you have enough sockets on the fax detector.

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
  

Set the machine in automatic mode. FAX ONLY

If you need more help you can go here:

http://welcome.solutions.brother.com/BSC/public/us/us/en/model_top/colormfc/mfc240c_all.html?reg=us&c=us&lang=en&prod=mfc240c_all

Note: check your equipment for:
Fax machine must be connected to an answer machine

Receiving a fax automatically:
1 Make sure the Fax Auto Answer light is on.
2 To set the number of telephone rings before the printer automatically receives faxes,
Receiving a fax with an answering machine
When a telephone ring is detected, the answering machine picks up the call.
• If the printer detects a fax, it receives the fax and disconnects the answering machine.
• If the printer does not detect a fax, the answering machine receives the call.
2 Set the answering machine to answer incoming calls before the printer does.
For example, if you set the answering machine to answer calls after three rings, set the printer to answer calls
after five rings.
3 To set the number of telephone rings before the printer automatically receives faxes.

First this is a good machine, I use the same one and have my fax setup for the same thing. If you have a (TAD) Telephone Answering Device first you have to set up your phone to pick up before the fax, do this by setting the phone to pick up on three rings and the fax to pick up on four. Go to Menu/Fax/Setup Receive/Ring Delay. While there make sure Easy Receive is on. The machine itself will distinguish between regular calls and facsimiles and will display this info at the time of the call on its LCD screen, make sure you are using the line connection and not the phone connection. Hope this helped.

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.