Biz 8 series with 2 fax units

[copyman]

Dont know much about 2nd fax line as I only have one customer that has always had 2 fax units in the machines I sold them over the years, starting with the Biz 223. They now have a 284e mono model and going to replace with a 458e. I added the 2 fax kits (used) and fax 1 has dial tone and both TX & RX work fine but fax 2 just hear a click with off hook dial, and send fails. I did change the small slide switch to line 2 on fax board, initialized, set country code. All by the book. Even tried another fax kit and same thing. Fax settings in service mode line 2 is set to TX & RX.
Not sure if it matters I only have one phone line in shop and unplug from fax 1 and plug into fax 2 to test. No dial tone on line 2.
Any settings I missed?
Thanks

[Synthohol]

i thought it will only use the 2nd fax if the first one is busy?
also where to plug in the phone lines is confusing in the directions,


<Only when using the telephone line>

(2) Insert the modular cable of the telephone line

to the modular jack (TEL) of the fax kit (Line 1). <Only when adding Line 2>

(3) Insert the supplied modular cable into the modular jack (LINE).

[Duplicator]

The off hook button will only work the first kit. If you have the default settings you need to tie up the line on fax kit one to get it to use line two. From what I can recall the second line can be set to receive only.