Question : Problem: IBM laptop winmodems modems can't connect to PBX

Our phone technicians in the field recently traded in their old laptops for new ones.  However, a number of older PBX's do not seem to be allowing the new modems to complete the dial in process.  e.g., after dialing in through hyper terminal, we either get garbled text or the handshake when dialing in does not complete and we are left hanging with the last high pitch note of the modems dial in tone.

If we use a US robotics modem, we are fine:

These are Conexant winmodems on IBMp t400's and t61's

Are their any possible ways to get these working more reliably?  I've already tried driver updates - but no luck.

Answer : Problem: IBM laptop winmodems modems can't connect to PBX

I have a conexant modem on a T61 and it is essentially useless extra weight. Sorry.   ..... T