I have a two hand set Icarus 2020 and one has stopped ringing on incoming calls and there I cannot hear the caller when I accept the call.

in profile management under caller settings you should find an option there to set the number of rings before timing out. Set it to whatever your preference is and it should solve your problem. otherwise it may be a provider issue, try calling AT&T and explaining what's going on.

You need to reset the main base and make sure the ringer volume is turned all the way up. Disconnect the power from the back of the main base, press and hold find hs key while reconnecting power until you hear long beep. Should reset base and handset.

is the ringging assignment setting
means downstair phone been set for incoming ring, so u can see the indicator ligh on and ringging
up stair dint assign a incoming ring so that u only can see the indicator light always blinking w/o ring...
contact yr phone provider to set the ringging assignment

You can raise the volume on the handset.
is it the ringing or the caller?
When you are the phone with the caller raise the VOL^ button.
[email protected]
Tony

Is the caller being transfered to the ext or is it on incoming calls?
Tony

binatone icarus 1500,no dial tone or incoming calls,cannot reset handset or base

cannot hear incoming calls or outgoing calls

The only reference to flash timing I can find in the manual is shown below for you, also here is link to manual :
I hope it helps !
http://www.uniden.com/products/productdetail.cfm?product=TRU8885-2

If you have Call Waiting service and a call waiting
tone sounds while you are on a call, press talk/flash
on the handset or flash/find hs on the base to accept
the waiting call. There is a short pause, and then you
will hear the new caller. To return to the original
caller, press talk/flash on the handset or flash/find
hs on the base again.

Setting the Ring Time
Ring Time allows you to set the number of rings the caller hears before your
answering system plays the outgoing message. You can set the ring time to answer
after two, four, or six rings. If you enable the Toll Saver (TS), the answering system
picks up after two rings if you have new messages and after four rings if there are
none.
1) Enter the Answ. Setup menu, and then the Ring Time
submenu (see "Entering the Menu" on page 16).
2) Press volume up/down to select a Ring Time (Toll
Saver, 2 Times, 4 Times, or 6 Times).
3) Press the OK soft key. You will hear a confirmation tone.
Setting the Record Time
Record Time sets the duration for recording the incoming messages. You have three
record time options. The options "1 minute" or "4 minutes" set the duration for
recording the incoming messages. "Announce only" answers the call but prevents
the caller from leaving a message.
1) Enter the Answ. Setup menu, and then the Record
Time submenu (see "Entering the Menu" on page 16).
2) Press volume up/down to select Record Time
(1 Minute, 4 Minutes, or Announce Only).
3) Press the OK soft key. You will hear a confirmation tone.