Service Mode And Adjusting Items And Datas - Haier RGBTV-25F99 Service Manual

10. Analysis of switch power circuits
The installed switch power source is a typical autonomous pulse switch power source.
When the switch is set to on or off, the pulse voltage of the 220V voltage from the
transmission line system rectified by VD810 rectifier is filtered by the capacitor C806
(220u) to obtain +300V direct current, which is added to (1) of the power integrated
circuits N801 (KA3S0680RFBYDFU inlet) through (1)(4) of the switch transformer T801
(BCK10002). When the appliance is first switched on, the initiating voltage to N801 is
supplied by an AC singlephase power source through activating the voltage dividing
resistor R803 and R802. When the appliance is operational, voltage is supplied by the
rectified pulse generated by (6) (7) of T801 coil. The coupler N802 (PC817C inlet)
functions to control voltage, and the voltage tolerance information from the switch
transformer T801 is transmitted to (4) of N801 through coupler N802 to regulate the
oscillation information of N801.
The pulse voltage output from the secondary (8) of the switch transformer T801, rectified
and filtered by VD805 (D5L60) and C816 (100u) is +130V direct current voltage which is
supplied to the output stage. The pulse voltage output from (13) is rectified and filtered by
VD807 (D6L20U) and C820 (2200u) and the resultant +15V direct current voltage is
supplied to the sound power amplifying circuits. The pulse voltage output from (11) is
rectified and filtered via VD806 (TR5GU41) and C818 (2200u) to obtain +12V direct
current voltage to supply the secondary source N804 (KA7630). +8V direct current
voltage, output from N804 (8), after rectification of the secondary source, is supplied to
the decoder chip. +5V direct current voltage from (9) is supplied to CPU N901 (Wh2000)
and capacitor N902 (KS24C08).
B. Service mode and adjusting items and datas
1.Factory adjustment information
Operation method: after the appliance is switched on, press P.STD, S.STD, CALL and
POWER keys on the remote controller to enter the management menu.
Press button MENU for selection.
Press P+/(CH+/) button to select items for adjustment.
Press VOL+/button to adjust selected items.
Press 1 6 buttons for quick selection of menus 1 to 6.
Press button 9 to select OSD sync signal cathode.
Press AV/TV to switch from AV to TV.
Press the MUTE button to select or deselect mute.
Press the POWER button to switch off the appliance.
Press other buttons to deactivate the maintenance menu.
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