85 Faultfinding tree & Repair facilitiesL7.3A
5.1Repair facilitiesTo leave the Service mode press the stand-by button on the
remote control.
5.2Functional blocks
REMARKS : After switching off and on the mains switch, the
set remains in the service mode (SDM- or SAM mode).
The PCB has service printing on both sides , so on the copper
and the component side. Functional blocks are indicated byFeatures are :
lines and text.
Y Service settings after entry
Test points are referring to the functional blocks as mentionedY Service (sub) menu selection
above :Y Error buffer display
Y Software version and identification display
� Test pointElectrical functionY Life timer (run timer) display
� P1, P2, etc. :Power supplyY Option bytes
� L1, L2, etc. :Line drive and line output
� F1, F2, etc. :Frame drive and frame output
� S1, S2, etc. :Synchronization5.4Initial states
� V1, V2, etc.: Video
� A1, A2, etc.: AudioThe initial state after switching on in service mode for System
� C1, C2, etc.:Controland Tuning are as follows :
� B1, B2, etc : BTSC stereo decoding
� N1, N2, etc.:NICAM stereo decodingY For Multi-System sets PAL BG/SECAM/DK/NTSC
Y For Bi-Norma and Tri-Norma sets NTSC/PAL-M/PAL-N
The numbering is done in for a diagnostics logical sequence.
Y For sets with VST tuning : Programme number 1 is
Example: Checking the power supply, start with test point P1,selected and the system will be tuned at the tuning data (for
P2 etc.programme 1) read from EEPROM
Y For sets with PLL tuning : Set is tuned to a frequency of
475.25 MHz.
5.3Service mode
Further settings :
The service mode is a pre-defined mode which can be used for
faultfinding and adjustments (especially when the TV gives noYThe automatic switch off (no IDENT) timer and the sleep
picture at all you can use the service default mode). Alltimer will be ignored
oscillograms and DC voltages in this service manual areYThe child lock will be disabled.
measured in the service default mode.YIf the TV sets was in hotel mode, this mode will be disabled
as long as the TV is in service mode.
The service mode is split into two parts :YBrightness, saturation, sharpness, contrast and balance
are initialised to 50% level.
Y Service Default Mode (SDM).YThe volume is set to 25% level.
Y Service Alignment Mode (SAM).YThe TV is normally controllable.
YAll displayed text strings in service mode, so SDM and
SDM. In the service default mode you are able to carry outSAM mode will be displayed in the English language.
(hardware) measurements under pre-defined conditions. To
entry the (SDM) Service Default Mode there are twoOther features
possibilities:
RAM test of the uP (=IC7600) and the NV RAM (=IC7620). At
Y Via the "DEFAULT" button on the Dealer Service Tool,every start-up of the TV, a read after write test for the complete
service codenumber : 4822 218 21232.RAM of IC7600 and via I2C the NVRAM (=IC7620) will be
YVia Short-circuiting the service pins M24 and M25 on PCBperformed. If this check fails, the appropriate error number will
and switching on the set via the mains switch. For M25 andbe written in the error buffer. The patterns will be chosen in
M24 see Diagram A4 and the PWB drawing of the mainsuch a way that every bit of all bytes, will be written high and
panellow. If the NVRAM is empty default values will be loaded.
In the SDM mode a "S" (in green) and the menu (in red) is
displayed (see Fig. 1).5.5SDM (Service Default Mode)
SAM. In the SAM mode you are able to align/adjust settings viaThis menu is being displayed whenever SDM is entered. In this
menu selection. To entry the (SAM) Service Alignment Modemenu the error buffer can be inspected, and the option byte(s)
there are two possibilities :can be (re)programmed. The overview of the menu is shown
below :
Y Via the "ALIGN" button on the Dealer Service Tool
YVia Short-circuiting service pins M28 and M29 on PCB andThe MENU UP/DOWN command can be used to select the
switching on the set via the mains switch. For M25 andnext/ previous option ; the MENU LEFT/RIGHT command can
M24 see Diagram A4 and the PWB drawing of the mainbe used to change the option value.
panel
In the SAM mode a "S" (in green) and the menu (in red) is
displayed (see Fig. 2).S (Service mode)
REMARKS: After the set is in the service mode the short circuit L73AP21 1.09999 (Life timer)
can be removed.(Software version) |
ACEC
PHILIPS
