Tone Dialer (430-0146) Troubleshooting Faxback Doc. # 14396 THE PHONE WORKS UNTIL I PICK UP AN EXTENSION PHONE, BUT IT QUITS AT THAT POINT. Picking up the extension line lowers the voltage, reducing the charge to the amplifier below the level it needs. The solution to this is simply not to pick up an extension phone. (TLC/all-03/29/95)