If you are customer of broadband you must have experienced these or at least some of these errors at least once in your system and then you keep scratching your head that what the hell went wrong when you were doing every thing according to the manual.
Well then its time for you to shampoo you scalp and stop scratching it cause here are those common errors and there solutions too.

1) Possible solution / fix for error 619

Broadband error 619 – The port is disconnected
Possible solution for error 619: Restart your computer and wait until all applications have completely loaded before trying to reconnect. Check your modem and phone cables are connected securely. If your problem has still not been resolved uninstall and reinstall your Broadband modem.
Error 619: The port is disconnected – Error 619 often occurs when another application / process requires the same port as being used by the broadband / internet modem. In particular, fax software is often associated with error 619. Should you encounter error 619 whilst using fax software – disable the fax software and reboot. The quick / common fix for Error 619 is to shut down / reboot, thus forcing the offending port to close.
To fix error 619, try the following steps:
1. Restart / reboot PC. Wait until all applications have loaded before reconnecting.
2. Check all modem, phone cables and filters.
3. If error 619 persists – uninstall and reinstall your Broadband modem. Sometimes, error 619 can be caused where old
ISP modem software is conflicting with newer modem software. Therefore, ensure that any old software is removed and retest the connection.
2) Possible solution / fix for error 629

Error 629 – The port was disconnected by the remote machine
Possible solution for error 629: Restart your computer and wait until all applications have completely loaded before trying to reconnect. Recreate the Dial Up Connection. If your problem has still not been resolved uninstall and reinstall your Broadband modem.
Error 629 – further information
Error 629 generally means that the remote computer (ISP) is closing / disconnecting the port. This might be due to incorrect connection settings such as incorrect username and / or password. Having checked these settings, if error 629 persists, it would be wise to check ISP server status for any server outages or other ISP related problems.
Having checked connection settings, ISP server status – the next step would be to check all modem connections, cables and broadband filters – followed by a PC and modem reboot. If Error 629 has still not cleared, you may wish to revert to either local or ISP technical support…or google error 629 to see what the forums have to offer.
One such listing details the causes of Error 629 as follows:
The modem driver is corrupt
The DUN connection is dialling an invalid access number
The modem is not attempting a compatible connection
Authentication failure (invalid username or password)
Invalid or corrupt DUN connection settings
And if you have anything further to offer regarding Error 629 – please do not hesitate to get in touch.
3) Broadband error code 631

Error 631 – The port was disconnected by the user
With error 631, the user disconnected themselves – there is usually no fix required – just connect again. Error 631 is usually a one-off glitch, caused when connection is interrupted by the user or another program on the PC.

Possible solution / fix for error 631
Possible solution for error 631
Error 631 is usually a one-off error which happens when the connection is interrupted by the user or another program on the PC. In order to resolve Error 631, all that is usually required is a restart and to wait until all applications have completely loaded before trying to reconnect. Recreate the connection and usually – no more error 631. In some circumstances, Error 631 can be caused by incorrect connection settings or by using the wrong modem or modem software. If a simple restart does not fix your error 631, check that the modem is correctly installed and connected, whilst ensuring that any old modem software has been uninstalled. If error 631 persists, technical support might be required or a google for error 631 to see if the forums have anything to offer.
4)Broadband error code 633

Error 633 – The port is already in use or is not configured for Remote Access
Possible solution / fix for error 633
Possible solution for error 633
Error 633 – The port is already in use or is not configured for Remote Access dialout
Error 633 is similar to Error 619 error and is often caused by other applications attempting to use the broadband modem, incorrect connection settings and sometimes a corrupt modem driver.
Error 633 can usually be resolved with a PC restart. This works 50% of the time. Failing this, error 633 might require best the user to disable any Firewall Software. Try to connect again. Recreate the connection and finally, try uninstalling and reinstalling the Modem.
5) Broadband error code 645

Error 645 – Internal authentication error
Possible solution for error 645
This problem tends to occur with users of Windows 98 or Windows ME and can often be resolved via the following steps:
Recreate the Connection.
Windows 95/98 – This error can occur if the Require encrypted password option is enabled on the Server Types tab in the connection’s properties, or an incorrect user name or password have been entered.
All versions of Windows – This error can occur if you are attempting to connect to a Windows 2000 domain that has had a RRAS (Routing and Remote Access Services) server log
on without administrative privileges.
6) Broadband error code 650

Error 650 – The Remote Access server is not responding
Error 650 can occur if the ISP server modem/equipment is not set up properly.
Possible solution / fix for error 650
Possible solution for error 650
The most likely reason for one of the above errors is a Network Problem. Consider the following steps:
. After receiving this error wait 15 minutes and then restart your computer. Once it has restarted wait until all applications have
completely loaded before trying to reconnect.
If you receive the same error, check with your service provider for Network Outages. You may need to be patient.
If there are no network outages, the problem may originate from your computer. In this case recreate your connection and if this fails to resolve the problem, uninstall and reinstall your
Broadband modem.
7) Broadband error code 651

Error 651 – Your modem (or other connecting device) has reported an error
Possible solution / fix for error 651
Error 651 – Your modem (or other connecting device) has reported an error.
Error 651 usually points to a driver error or modem hardware failure. To resolve Error 651, first ensure that the modem is correctly connected to the PC and telephone line, with all points covered with broadband filters. Ensure that full connectivity is indicated on the modem. Having checked these things – restart. If this does not resolve the error 651, go through an uninstall and reinstall of the modem software. Thereafter, if Error 651 persists, it’s possible that the modem is faulty. If the modem is the USB variety, try connecting to a different USB port on the PC or another PC entirely to confirm
that it is not a problem with USB port. If Error 651 still persists, technical support is indicated.

Possible solution / fix for error 678

Broadband error 678 – There is no answer
Error 678 is usually associated with Windows XP and can normally be resolved by restarting and waiting until all applications have completely loaded before trying to reconnect. Although ADSL modems do not dial to connect to the internet, error 678 – no answer – can still occur and sometimes results because there is an invalid number entered for the computer to dial.
The following steps are often indicated to fix Error 678:
Click on the Start Menu and then select Run.
In the box which appears type the word command in order to open the command prompt and then click OK.
In the black command prompt window, type netsh interface ip reset log.txt and click on Enter on your keyboard.
Then type exit into the command prompt and then click on Enter on your keyboard.
Now restart your computer and reconnect to the Internet.
9) Possible solution / fix for error 691

Broadband error 691 – Access denied because username and/or password is invalid on the domain With all Windows versions – Error 691 can occur if you use a bad username or password; remember in most instances the password is case-sensitive – you will not see the password, so if CAPS LOCK is not the way you expect it, you may have a problem with upper/lower-case. It may also occur if there is a problem with your service provider’s access equipment, or on a ‘bad’ connection where the modem is retraining. Can also occur with incorrect Connectoid settings.

If you get error 691 with a new account – you may not be using the correct username and/or password. Verify with your provider exactly what you need for your username and password.
10)Possible solution / fix for error 718

Broadband error 718 – PPP timeout
Error 718 indicates a PPP conversation was started, but was terminated because the remote server did not respond within an appropriate time. This can be caused by poor line quality or a problem with the server (ISP). This error can occur when your modem has connected to the ISP and has sent username and password, but there is no response from the server. Sometimes, re-dialing will be successful.Error 718 can also occur if your ISP account has expired, or if the username or password you are using is invalid. Error 718 can occur if you have LCP extensions enabled in the TCP/IP Properties of the connectoid and your ISP does not support LCP extensions.

Error 718 may also occur if you have one or more network cards in your machine, and the cards do not have TCP/IP protocol enabled, or if the TCP/IP settings are incorrect. (Go to Networking in Control Panel to examine the properties of your network adapters; or, if you are not using the network card(s), disable them in Control Panel->System->Hardware.)
11) Broadband error 721 – Remote PPP peer is not responding

Possible solution / fix for error 721
Make sure your line is working by testing for a dial tone on your phone. Unplug, reboot and plug in again to ensure the driver has loaded. If there’s still no joy, don’t discount the possibility of a faulty modem.

More about Error 721
Error 721 generally means that there is a problem with the remote PPP – the PPP server resides with the Internet / broadband provider and is the computer at ‘the other end of the line’ that establishes connections to the Internet. The majority of Error 721 messages are caused by a ‘problem’ with the Internet service provider. Most Internet service providers have a number that can be called to check their service status. With Error 721 problems, it is therefore worth checking the ISP’s service status before checking other possible causes.
Another possible cause of Error 721 messages can be displaced modem connections, adsl cables and / or broadband filters. If an Error 721 message has not been caused by the ISP, it would be prudent to check all such connections. Common advice is then to shut down both modem and PC and to wait 5-10 minutes before restarting them. Wait until all PC application have fully loaded before attempting to reconnect to the Internet.
Where there are no ISP service issues and all modems, filters, cables are correctly connected – another possible Error 721 fix would be to check all associated PC settings and to update / uninstall modem drivers, reboot and reinstall them again and whilst doing so – take care not to connect the modem until prompted to do so by the setup program.
Where no fix is found for Error 721, if time allows – wait 24 hours and try again or seek either local or ISP technical support. You might also be advised to google for error 721 as there is a wealth of information available via the various forums and blogs.
And should you have anything to add or offer regarding error 721, please do not hesitate to contact us.
12) Possible solution / fix for error 797

Possible solution for error 797
Restart your computer and wait until all applications have completely loaded before trying to reconnect.
If your problem has still not been resolved uninstall and reinstall your Broadband modem.
13) Broadband error 680 – No dial tone

Possible solution / fix for error 680
Error 680 usually means there is a problem receiving the Broadband signal at your modem.
Error 680 (no dial tone) has a great many potential causes. The best way to resolve Error 680 is to work logically to rule out each potential cause. The first consideration is to know if the broadband connection is actually live. Installing modem and modem software can result in Error 680 if the ‘go-live’ date has yet to be reached. The next ‘fault find’ is to ensure that the modem is connected to the telephone master socket, whilst ensuring that all extension cables, phone splitters and all other devices have been removed. Disconnect faxes, alarms and Sky TV (if connected) and once removed, attempt a broadband connection direct via the telephone master socket (ensuring that a broadband microfilter is being used. If Error 680 persists, try using a replacement microfilter (sometimes a cause of error 680). The next thing to consider with Error 680 is electrical interference from cordless / digital phones and any other potential sources of electrical energy. Having ruled out all of these potential causes, one remaining consideration would be to update the modem drivers, which in most cases can be obtained from the manufacturers website.
If after these steps, Error 680 persists, technical support would be the next course of action.
OTHER ERROR CODE :

600 An operation is pending.
601 The port handle is invalid.
602 The port is already open.
603 Caller’s buffer is too small.
604 Wrong information specified.
605 Cannot set port information.
606 The port is not connected.
607 The event is invalid.
608 The device does not exist.
609 The device type does not exist.
610 The buffer is invalid.
611 The route is not available.
612 The route is not allocated.
613 Invalid compression specified.
614 Out of buffers.
615 The port was not found.
616 An asynchronous request is pending.
617 The port or device is already disconnecting.
618 The port is not open.
619 The port is disconnected.
620 There are no endpoints.
621 Cannot open the phone book file.
622 Cannot load the phone book file.
623 Cannot find the phone book entry.
624 Cannot write the phone book file.
625 Invalid information found in the phone book.
626 Cannot load a string.
627 Cannot find key.
628 The port was disconnected.
629 The port was disconnected by the remote machine.
630 The port was disconnected due to hardware failure.
631 The port was disconnected by the user.
632 The structure size is incorrect.
633 The port is already in use or is not configured for Remote Access dialout.
634 Cannot register your computer on the remote network.
635 Unknown error.
636 The wrong device is attached to the port.
637 The string could not be converted.
638 The request has timed out.
639 No asynchronous net available.
640 A NetBIOS error has occurred.
641 The server cannot allocate NetBIOS resources needed to support the client.
642 One of your NetBIOS names is already registered on the remote network.
643 A network adapter at the server failed.
644 You will not receive network message popups.
645 Internal authentication error.
646 The account is not permitted to log on at this time of day.
647 The account is disabled.
648 The password has expired.
649 The account does not have Remote Access permission.
650 The Remote Access server is not responding.
651 Your modem (or other connecting device) has reported an error.
652 Unrecognized response from the device.
653 A macro required by the device was not found in the device .INF file section.
654 A command or response in the device .INF file section refers to an undefined macro
655 The macro was not found in the device .INF file section.
656 The macro in the device .INF file section contains an undefined macro
657 The device .INF file could not be opened.
658 The device name in the device .INF or media .INI file is too long.
659 The media .INI file refers to an unknown device name.
660 The device .INF file contains no responses for the command.
661 The device .INF file is missing a command.
662 Attempted to set a macro not listed in device .INF file section.
663 The media .INI file refers to an unknown device type.
664 Cannot allocate memory.
665 The port is not configured for Remote Access.
666 Your modem (or other connecting device) is not functioning.
667 Cannot read the media .INI file.
668 The connection dropped.
669 The usage parameter in the media .INI file is invalid.
670 Cannot read the section name from the media .INI file.
671 Cannot read the device type from the media .INI file.
672 Cannot read the device name from the media .INI file.
673 Cannot read the usage from the media .INI file.
674 Cannot read the maximum connection BPS rate from the media .INI file.
675 Cannot read the maximum carrier BPS rate from the media .INI file.
676 The line is busy.
677 A person answered instead of a modem.
678 There is no answer.
679 Cannot detect carrier.
680 There is no dial tone.
681 General error reported by device.
682 ERROR WRITING SECTIONNAME
683 ERROR WRITING DEVICETYPE
684 ERROR WRITING DEVICENAME
685 ERROR WRITING MAXCONNECTBPS
686 ERROR WRITING MAXCARRIERBPS
687 ERROR WRITING USAGE
688 ERROR WRITING DEFAULTOFF
689 ERROR READING DEFAULTOFF
690 ERROR EMPTY INI FILE
691 Access denied because username and/or password is invalid on the domain.
692 Hardware failure in port or attached device.
693 ERROR NOT BINARY MACRO
694 ERROR DCB NOT FOUND
695 ERROR STATE MACHINES NOT STARTED
696 ERROR STATE MACHINES ALREADY STARTED
697 ERROR PARTIAL RESPONSE LOOPING
698 A response keyname in the device .INF file is not in the expected format.
699 The device response caused buffer overflow.
700 The expanded command in the device .INF file is too long.
701 The device moved to a BPS rate not supported by the COM driver.
702 Device response received when none expected.
703 ERROR INTERACTIVE MODE
704 ERROR BAD CALLBACK NUMBER
705 ERROR INVALID AUTH STATE
706 ERROR WRITING INITBPS
707 X.25 diagnostic indication.
708 The account has expired.
709 Error changing password on domain.
710 Serial overrun errors were detected while communicating with your modem.
711 RasMan initialization failure. Check the event log.
712 Biplex port is initializing. Wait a few seconds and redial.
713 No active ISDN lines are available.
714 Not enough ISDN channels are available to make the call.
715 Too many errors occurred because of poor phone line quality.
716 The Remote Access IP configuration is unusable.
717 No IP addresses are available in the static pool of Remote Access IP addresses.
718 PPP timeout.
719 PPP terminated by remote machine.
720 No PPP control protocols configured.
721 Remote PPP peer is not responding.
722 The PPP packet is invalid.
723 The phone number, including prefix and suffix, is too long.
724 The IPX protocol cannot dial-out on the port because the computer is an IPX router.
725 The IPX protocol cannot dial-in on the port because the IPX router is not installed..
726 The IPX protocol cannot be used for dial-out on more than one port at a time.
727 Cannot access TCPCFG.DLL.
728 Cannot find an IP adapter bound to Remote Access.
729 SLIP cannot be used unless the IP protocol is installed.
730 Computer registration is not complete.
731 The protocol is not configured.
732 The PPP negotiation is not converging.
733 The PPP control protocol for this network protocol is not available on the server.
734 The PPP link control protocol terminated..
735 The requested address was rejected by the server..
736 The remote computer terminated the control protocol.
737 Loopback detected..
738 The server did not assign an address.
739 The remote server cannot use the Windows NT encrypted password.
740 The TAPI devices configured for Remote Access failed to initialize or were not installed
correctly.
741 The local computer does not support encryption.
742 The remote server does not support encryption.
743 The remote server requires encryption.
744 Cannot use the IPX net number assigned by the remote server. Check the event log.
752 A syntax error was encountered while processing a script.