Mark Levinson No.26 Balanced Input Question

My ML no.26 preamp has phono. It works fine with turntable (AUX2) and RCA input to CD. Yesterday I tried connect balanced input to CD player via XLR cable and no sound come out of speakers. I then follow the manual reset DIP switches on the phono boards no luck. Did I do right? Or something I missing. Please help. Thanks.
What happens when you connect the CD player to the balanced AUX2 inputs?

If nothing, its most likely that the CD player is having a problem.

If it plays then the preamp is the issue.
No. 26 was only available with either the balanced input or the phono input boards, not both. So, if yours has the phono board it does not have the balanced, even if it has the input jacks.

you get phono, balanced or neither. Cannot have both.
no sound when I connect CD Player and 26 balanced input. Connect CD to RCA works fine.
As I recall with the No. 26 you could have either the internal phono board option or the balance operation board. But not both. This is why the balanced output does not work.

The DIP switches on the phono board most likely control gain and loading options.
The DIP switches on the PHONO board has 5 settings. The last one is"Optional". I thought this is for balanced input. If No.26 can't has both PHONO and Balanced, what does "Optional" mean?