Philips BJ2.4U Service Manual

Service Modes, Error Codes, and Fault FindingEN 18 BJ2.4U/BJ2.5U PA5.• POD key validity. Indicates the key’s validity, this will onlywork with an authentic POD card.• Digital Signal Quality. not applicableHow to Exit CSMPress any key on the RC-transmitter (with exception of the“CHANNEL +/-”, “VOLUME”, “MUTE” and digit (0-9) keys).5.2.4 Service Mode of Converter Boards for Ambi LightPurposeTo switch on the lamps manually in case I 2C-bus triggeringfails.The Service Mode can be activated by disconnectingconnectors 1M59 and 1M49 and then by shorting for a momentthe two solder pads [1] on the Ambi Light Inverter Panel. Seefigure “Service Mode pads AmbiLight panel”.Figure 5-3 Service Mode pads AmbiLight panelIn this chassis, both single and double fitted boards can beused. The double fitted boards are used in sets with 3 or 4sided Ambi Light units whereas the single fitted boards areused in sets with 2 sided Ambi Light units. A double fitted boardcan drive 2 lamp units (6 lamps) and a single fitted board candrive 1 lamp unit (3 lamps).The double fitted boards are supplied by +12Va and +12Vb.The microprocessor is supplied by +12Va.Therefore, if only +12Va is available, lamp unit B will not work.See figure “Building blocks of Converter Board” for details.Figure 5-4 Building blocks of Converter BoardThe microprocessor performs the following tasks:• Dimming of Ambi Light by means of PWM.• Translation of I 2 C-bus commands to PWM.• Switches the Ambi Light board to protection if needed (incase of protection only the lamps switch off, no setprotection is triggered).There are two ways of protection: parallel arcing protection andserial arcing protection.Parallel arcing protection is performed by sensing the switchingfrequency. In case of short circuit of the transformer output, thisfrequency > 100 kHz and the board goes into protection.Serial arcing protection is performed by detection of arc inground wire of the lamp units. In this case, the protection pulseis transmitted via an opto-coupler.Protection can be disabled by short-circuiting diode 6112 orcapacitor 2173 or by connecting pin 8 of the microprocessor toground.G_15950_049.eps0604061G_15950_050.eps060406μ ProcessorPWM out+12Va+12Vb (12-13V)InvertersLamp unit ALamp unit BI²C+5VStab.+12VaBoard selectProtection