Serial async dialbackup ports not working after shut, no shut??

Question

I have four serial interfaces with async modems configured for dial-back to remote sites. While testing the dial-backup to the remote sites I noticed that host router was always using the same serial port to dial each remote site. In order force the dial backup mechanism to use another of the four host modems, I did a "shut" on the serial interface with the modem. Although this did force the dialer to use another modem in the pool, after doing a no shut on the modem serial interfaces I found that it was unusable for dial-back after that, that is, the dialer could not dial-out on the modem. I had the customer power cycle the modems on the serial interfaces but they still shows as down. Below is a sample excerpts of my config:
interface Serial2/0
description *** Dial Back-Up #1Phone***
no ip address
encapsulation ppp
no ip route-cache
no ip mroute-cache
dialer in-band
dialer pool-member 1
dialer pool-member 2
dialer pool-member 3
dialer pool-member 4
dialer pool-member 5
dialer pool-member 6
dialer pool-member 8
dialer pool-member 9
fair-queue
pulse-time 1
no cdp enable
interface Dialer1
description *** Dial Back-Up to Bridgton ***
ip address 172.21.1.2 255.255.255.248
encapsulation ppp
dialer pool 1
dialer rotor best
dialer idle-timeout 300
dialer wait-for-carrier-time 60
dialer string 99473624
dialer-group 1
no cdp enable
ppp authentication chap
Anyone ever see this. How can I re-initialize the serial ports with the modems again. No shut does not seem to work??
Thanks,
Tony

Answer 1

Hello Tony,
not sure if this helps, but try the interface command 'ignore-dcd' on your serial interface(s); the modem might be sending a DSR (data set ready), while the interface would listen for DCD (Data Carrier Detect) as up/down indicator.
Regards,
Nethelper