Thanks you very much for this "hard to find" service manual.
Will help a lot in repairing this tuner.
Text excerpt from page 16 (click to view)
SECTION 3 TEST MODE
BASE UNIT
� MAIN Section � [Setting the Test Mode] 1. Power on with pressing the [INTERCOM] key for five seconds. 2. When the test mode is set, it beeps confirm tone and CHARGE LED turns on for 50 msec. Note: If setting the test mode with the status that [TONE] position is selected at [DIAL MODE] switch, the unit cold stars next time when the power is
turned on.
[Releasing the Test Mode] To release the test mode, perform as follows: � Turn the power off (disconnect the AC adapter plug). � Set the handset to charge on the base unit (except Test Mode 9). � Bell in. [Changing the Test Mode Step] 1. Set the [DIAL MODE] switch to the [PULSE] position. 2. Press the [INTERCOM] key. 3. A step is changed each time the key is pressed, and CHARGE LED turns on for 50 ms and it beeps confirm tone. [Changing the Channel] 1. Set the [DIAL MODE] switch to the [TONE] position. 2. Press the [INTERCOM] key. 3. A channel is changed each time the key is pressed, and CHARGE LED turns on for 50 ms and it beeps confirm tone.
Note: Channel will be back to initial channel (19CH), when the test mode step is changed.
