Fax line causing fax machine to reboot.
Here's an odd one. We have an HP color LaserJet MFP M283fdw Fax/Scanner/Printer. When using the regular fax line (line 2 on the comcast modem) sending a multi-page fax the machine sends one single page, and then it reboots! Every single time! But if I plug the fax into line 1 (which is our primary voice line) it will send mutli-page faxes with no problems.
I've plugged a phone into each line to listen for line noise, and get a clear dial tone on both. Even pressed a digit to silence the dial tone so I could hear even the faintest of line noise, and both the primary voice and secondary fax line are crystal clear.
I've plugged the fax machine directly into the modem, and on line 1 (primary) it works perfectly. But on line 2 (fax line) it reboots the fax/scanner/printer immedidately after sending page 1, and it does this every single time.
We've had this comcast provided modem for a few years now. So is it time for a replacement?
EDIT: We've replace the machie with a brand new HP MFP machine, and it still does the same thing? So i've ruled out every possible cause except the comcast telephone modem.