1 of 1 people found this helpful
Offhand, it does sound like a bad FXO module. For the "hum" you can try adjusting the "Tx Gain" under MODULES, in the CONFIG for the FXO Module. The Tx gain will be the level transmitted to the PRI.
The "no dial tone" is what makes me believe the module may be bad. You can try adjusting the gain, but I doubt it will make a difference. If you can hear dial tone using a butt set on those lines, then dial tone is there.
You can also try moving the FXO module to a different slot in the chassis, but it doesn't look good.
Of course I don't have another FXO in stock to swap, but I think I'm going to have to find one. I did attempt gain adjustments, and while that seemed to have a minimal effect on the audio level of the actual call audio in the background of the noise, it didn't affect the noise at all and there was no change on the dial tone issue.
Dial tone (and in fact successful call function) is present on the lines in question with a butt set. I'll report back after I've had a chance to swap the card.