SPA 504 G phone connected to UC 540W-FXO-K9 with no dial tone

[h.luo]

Hello,

I have UC 540W-FXO-K9 with latest Bin 8.6.2 and new SPA 504 G with latest firmware 7.5.7s. It seems the Phone can register with UC 540 with no issue. However, I cannot hear any dial tone when I pick up the phone. However, once I dial the extension of the phone, it does ring fine. Any idea?

SPA 303 phone works fine with no issue though.

Thanks in advance.

[h.luo]

I reset UC 540 to factory default, and found out that the phone only have dial tone once I put speaker mode, Once I pick the phone up, there is no tone and I cannot hear anything? both new 504G have the same issue. Bad phone hardware or something else? The same happens to a new SPA 525 G2 phone.

UC IOS version: Cisco IOS Software, UC500 Software (UC500-ADVIPSERVICESK9-M), Version 15.1(4)M6, RELEASE SOFTWARE (fc2)

thanks again