Cannot pick up the phone!

According to iPhone faq.org: " How can set the number of rings on my iPhone before voicemail picks up?
You can set the iPhone to wait longer or shorter than the default 20 seconds before it goes to voicemail when receiving an incoming call. This will result in a different number of rings before the voice messaging system picks up the line and plays your outgoing message. To change the amount of time the iPhone will ring follow these steps:
1. Open the phone app and dial *#61# on the Keypad. Press the Call button.
2. Locate this text on the screen: "Setting Interrogation Succeeded, Voice Call Forwarding, When Unanswered, Forwards to +" and record the 11-digit number after the + symbol.
3. Touch the Dismiss button. Now enter this code on the Keypad: *61*+ followed by the 11-digit Forwards to number recorded in step 2, followed by *11 and *ringtime#. Ringtime is the number of seconds you want your iPhone to ring before voicemail picks up. Your finished code should look something like this:
*61*+18555513466*11*30#
In the example above the ring time is set to 30 seconds. Press the Call button.
4. You should receive the message: Setting Activation Succeeded. Press Dismiss and next time you receive a call it will ring for the new amount of time before going to voicemail."
According to Apple Tool Box.com: "having this problem, please try the followings:

• Make sure that iPhone's Ring/Silent switch is OFF meaning ringer is ON. A bell will flash briefly on the screen when you turn on the ringer.
• Make sure that the Do Not Disturb setting is not silencing calls (Settings > Do Not Disturb).
• Make sure that Airplane Mode is OFF (Settings > Airplane Mode).
• Make sure that your carrier software is up to date (Settings > General > About)."
  
  AccorA

Go to Settings, My device, then scroll down to ringer. Slide the bar all the way to the right for ring time. Then back out of the screen. Test it to see if you like that better.

Maybe it is defective, call customer service

If your printer is connected to a modem make sure that the port has a dial tone. To check for dial tone, try to plug in a phone to the same port that you printer is connected to. If it doesn't have dial tone, you might want to check with your phone provider. Or you can plug in the printer straight to a wall jack.

Once the printer is connected to a line that has dial tone, you can then setup the printer to receive faxes. To set it up, on the control panel of your printer, press on Setup > Fax Setup > Ringing and Answering.

If you have an answering machine, set your printer to pick up 3 rings higher than your answering machine. If not, set it to pick up on the 5th ring that way you will still have time to pick up the phone if it's a voice call.

If you have a voicemail service from your phone provider, you'll need to contact your phone provider to get a distinctive ring feature. Once you'll have that feature, you can assign a distinctive ring to your printer. You can find that under Fax Setup > Ringing and Answering > Ring Pattern.

The manual for this phone doesn't say you can turn the answering machine on remotely, but every one I've ever seen can do so. Most of them say call your number and let the phone ring...and ring...and ring, and eventually the answering machine will turn on. Ten rings is what I've seen most often. I guess the manufacturers figure most callers will hang up fairly soon if the machine doesn't answer, so they pick a large number. Try it on your phone; worst that can happen is it won't work.

Have you tried erasing all the (incoming) messages on the machine? Does that let it ring the full 4-ring-cycle before it picks up?

It's been years since I owned one of these, but there should be a switch (on the side of the unit?) for a feature called "toll saver" If you find this, switch it off.

The idea was from the days of payphones -- if the machine had no messages, it would ring 4 times before it picks up. If there were messages, it would pick up after one ring (or sometimes two)

If you were out on the town and wanted to check your messages, you'd put your dime in a payphone and call home. If it rang three times, you can hang up the payphone and get your dime back, knowing there's no message to check.

Call Pickup doesn't ring your phone or light up. Your 5212 phone isn't considered a "display phone" Meaning that the display doesn't have softkeys. These are the 3 keys directly below the display and their function changes as you are using the phone.

Your phone's Pickup Key should be used if you want to pick up a call that is ringing on a nearby telephone... usually only the phones within earshot of your phone.

You must pick up the handset, then either press the call pickup key or dial the call pickup feature code.... this code can be different for every system as it's custom from the install vendor.

I hope this helps.
Mark

Looks like the basic functions of the phone are correct. Remain the answering machine. Are you sure it can act as an answering machine?
If it can act as answering machine the reason it is not doing so may be the following.

1. Answering function is turned OFF
2. Answering function may be ON but the number of rings before it answers is set too high.

I suggest you try the following
Call you phone. Let it ring at least 10 times. If it can act as an answering machine it will pick up the phone and read the welcome message, because most answering machines (the recent ones at least) answer after 10 rings even if answering function is turned OFF.

The phones that can be answering machines usually do have a display that shows the number of incoming messages, or a LED that flashes to let you know that you have new recorded messages.

I have a HP Officejet J6480 All-In-One and needed the answering machine and fax to be on at the same time.  I called the help line at HP and they said I needed another phone line into the home but I tried this and it worked. 
First I got a different phone number for the fax machine - they do this for no charge at my phone company. This is not another physical line into the home - it is just another phone number with a different ring - it rings 2 fast rings for the fax machine instead of the phones regular one ring. I set the answering machine built into the phone to pick up after 4 rings and I set the fax machine to pick up on 2 rings. Be sure to set it so the fax pick up number of rings are less than the answering machine pick up number of rings.  It worked for me. Hope this works for you too.

The phone does not have this facillity.However,switching the answer machine "OFF" allows me to lengthen the ringtone to 16 rings as on the Users Guide.

Many thanks for your interest,