I'd suggest you try some different numbers, outside your area code. Also, you should dial the numbers on a phone to be sure that you're getting through and that the number is still good.

The dialing prefix should be:

,#019,,XXXXXX

Replace XXXXX with the number you'd dial, as you'd dial it on your phone.

Dear Jeff, tried your ,#019,,7024420568 suggestion to force a dial in connection on my replacement R-10, but I got a "failed..could not connect response". I went to the SET DIAL IN NUMBER screen and reentered my area code. Pressed enter and waited while the screen said it was retrieving a list of local dial in numbers. I got the "failed..could not connect" message". I got the above dial in number from my "Original" R-10 which I plugged into the same phone line last night and booted back up with its' non-valid access card. I was able to perform some basic functions on that receiver, one of them was I was able to successfully place a call and get account updates. That proved again that the phone line is good and the dial in number is also good. (I just called that same dial in number from a telephone and got a healthy modem signal coming back to me.) As I said before this is my 3rd replacement Directv R-10, and none of them were able to place a call. The first 2 gave me the message "failed..line busy" and this current one gives me the "could not connect" message. I currently have 3 Directv R-10s sitting in front of me to try different things on, but only one has a valid access card.
The continuing circumstance with all of the replacements is that all 3 came from different parts of the country and had different dial in numbers which they did not want to update. Also all 3 had not been activated in MANY YEARS and have old software versions. My "Original" receiver has software version 6.4a-01-2-521 and the current one has software version 6.1-01-2-521 and is giving me the message that it has been 3100 days since the last successful call. Also the Service Map Version is 22:TIVOPVRSpigotMAP on my Original receiver and is 21:TIVOPVRSpigotMAP on the current one. I believe these should update upon a successful call out. I followed your online instructions to Kickstart the current receiver and entered 52 to cause an emergency software install. I got the message "Installing updates, this will take a few minutes" so I thought I was successful, but the software version did not change and the receiver could still not place a phone call. I repeated this operation a second time and got the same results. I even did a Kickstart and entered 0 for an emergency dial in, but it seemed to not work, because I got no on screen notification. The Tech. at Directv was little help, but I did have him perform some resends of authorizations just in case. Of course he told me to wait 24 hrs. and the satellite would "magically" send updates and update my TIVO software versions. I have this replacement receiver working and can watch some programming, but the time zone does not match, the guide is not updated and I do not have local channels because the receiver thinks it is still in New York State instead of Las Vegas. If I buy a brand new Directv R-10 receiver that does not already have a dial in number entered in it that I have to update, might this solve my problem? And how do I get a list of different dial in numbers outside my area as you suggested?

I think you need a "1" in there:

,#019,,17024420568

Michael, tried the "1" in my dial in number prefix string, but still got "failed could not connect". This is a local number and we must dial the area code for local calls now. I called 7024420568 by phone and got a normal long modem "beeeeeep" signal. Tried it again with the 1 in front and got a voice message about 'your call could not be completed". After 10 days of trying to make an outbound call. I must now conclude that the modem on my replacement R10 is not working. Before I invest in your external modem, I want to confirm this machine can make the two outbound calls necessary for set up and is a good receiver. (I can get partial programming without the final setup calls, but no locals and very limited record ability...but this is enough to make me think the hard drive is good and the receiver may be worth rescuing.) What I have is my original R10 with a failing hard drive (it constantly resets itself) but it can make the outbound calls and is able to look up the local dial up number so it has a good modem. And I have this replacement R10 with an apparent bad modem and what I believe is a good hard drive. They are both Series 2 and both Model R52180, their only difference is the software versions, one is 6.1-01-2-521 the other 6.4a-01-2-521. Is there a way for me to link the two receivers together through their serial ports or other ports and force a dial up call and let the two default to the one good working modem, or force them to use the one working modem with a setup string? If I can, then I can make my decision to either buy your external modem for the replacement R10 so I can have a working receiver or swap the bad hard drive from my original R10 for the assumed good one in the replacement R10 by myself, and keep my original R10 (with the good modem) alive a while longer. (From the online instructions, a hard drive swap with an already formatted drive seems pretty straightforward and looks like a plug and play operation.) I am currently using a recently received Directv R22 standard definition DVR and would rather poke my eyes out than continue with it any longer. I am one of those fixed income people and the Directv HD TIVO is probably never going to happen for me except in my dreams.