Microphone Switch And Light-Ring; Internal Signals For Delegate And Chairman Units; Internal Signals Only For Delegate Units - Philips CCS 800 Service Manual

10.3.5 Microphone switch and Light-ring

Press the microphone button on the Delegate/Chairman Unit. The Light-ring must lit now (M70 related to M8 (0V)
should be between 7.0V and 9.0V)

10.3.6 Internal signals for Delegate and Chairman units.

Power reset
Decrease the power supply of the CPSU which is connected to X10 so that V+ related to M2 (GND) is successively +15V
and 12.8V.
Measure the Power-reset voltage via M14 of the Delegate or Chairman Unit, related to M8 (0V).
V+ M14
+15V < 1V
+12.8V > 4V (Power-reset activated)
Increase the power supply V+ back to +19.5V
TEST mode
Set the Mode switch at the CPSU successively in the Test and Auto mode.
Measure the DC-voltage via M31 related to M8 (0V).
Mode switch M31
Test mode > 4.0V (TEST is activated)
Override mode < 0.5V (TEST is inactive)

10.3.7 Internal signals only for Delegate Units

Override Mode (ORM)
Set the Mode switch of the CPSU successively in the Test and Override mode.
Measure the DC-voltage via M35 related to M2 (GND).
Mode switch M35
Test mode > 4.0V (ORM is activated)
Override mode < 0.5V (ORM is inactive)
Set the Mode switch of the CPSU in the Override mode
Press the microphone button and measure the DC-voltage via M5 related to M2 (GND).
Detect the presence of a voltage pulse > 13.0V (after the pulse of 5.7V).
LBB 3310/00, 3330/00 and 3331/00
4822 861 11006
page: 29
SERVICE MANUAL
Date of issue:
July 1998