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5. Fault finding and repair tips
In this chapter the following paragraphs are included:
1. Test points.
2. Service Modes.
3. Problems and solving tips (related to CSM).
4. ComPair.
5. Error codes.
6. The 'blinking LED' procedure.
7. Protections.
8. Repair tips.
5.1
Test points
The EM1A chassis is equipped with test points in the service
printing. These test points are referring to the functional
blocks:
•
A1-A2-A3, etc.: Test points for the audio processing
circuitry [A5, A6, and B6].
•
C1-C2-C3, etc.: Test points for the control circuitry [B7].
•
F1-F2-F3, etc.: Test points for the frame drive and frame
output circuitry [A4, B4] and Double Window [C].
•
F1F-F2F, etc.: Test points for the RGB-signals on the
CRT panel [F].
•
I1-I2-I3, etc.: Test points for the intermediate frequency
circuitry [A7, B2].
•
L1-L2-L3, etc.: Test points for the line drive and line
output circuitry [A3, B4].
•
P1-P2-P3, etc.: Test points for the power supply [A1, A2].
•
SC1-SC2, etc.: Test points for the synchronisation
circuitry on the CRT panel [F].
•
V1-V2-V3, etc.: Test points for the video processing
circuitry [B].
The numbering is done, in a for diagnostics logical sequence;
always start diagnosing within a functional block in the
sequence of the relevant test points for that functional block.
Measurements are performed under the following conditions:
•
Service mode: SDM.
•
Video: colour bar signal.
•
Audio: 3 kHz left, 1 kHz right.
5.2
Service modes
5.2.1
Service Default Mode (SDM)
Purpose
•
To provide a situation with predefined settings to get the
same measurement results as given in this manual.
•
Start the 'Blinking LED' procedure.
•
Have the possibility to override the 5V-protection.
Specification
•
Tuning frequency 475.25 MHz for PAL/SECAM sets and
at channel 3 (61.25 MHz) for NTSC-sets.
•
All picture settings at 50 % (brightness, colour, contrast,
hue).
•
All sound settings at 50 % except volume at 25 % (so
bass, treble, balance at 50 %, volume at 25 %).
•
All service-unfriendly modes are disabled, like timer,
sleep timer, parental lock, blue mute, hospitality mode
and no-ident timer (normally the set is automatically
switched off when no video signal - IDENT - was received
for 15 minutes).
Entering
•
Via a standard RC-handset by entering the code
'062596' followed by the 'MENU' button.
•
Via ComPair.
Fault finding and repair tips
•
•
CAUTION: Entering SDM by grounding the 'Front Detect'-
line will override the 5V-protection. This should only be
done for a short period of time. In case of SW-protections
(errors 1 - 4), the set will shutdown in 15 s.
When doing this, the service-engineer must know what
he is doing as it could lead to damaging the set.
After entering SDM, the following screen will be shown with
'SDM' at the upper right side for recognition.
SDM Menu
H R S : 0 0 0 1 S W I D : E M 1 1 A 1 - 1 . 0
E R R : 0 0 0 0 0 0 0
Explanation
Access to normal user menu
Pressing the 'MENU' button on the remote control, switches
between the SDM and the normal user menus (with the SDM
mode still active in the background).
Error buffer
Pressing the 'OSD' button [i+] of the remote control, shows /
hides the error buffer. OSD can be hidden to prevent
interference with oscillogram measurements.
Access to SAM
By pressing the 'VOLUME +' and 'VOLUME -' buttons on the
local keyboard simultaneously for a few seconds, the set
toggles from SDM to SAM.
Exiting
There are 2 ways to exit this mode:
•
•
5.2.2
Service Alignment Mode (SAM)
Purpose
•
•
•
Specification
•
•
•
•
•
EM1A
Via grounding the 'Front Detect'-line on the Side I/O
panel during switch ON (pins 1 and 7 of connector
0936).
By the 'DEFAULT' button on the DST while the set is in
the normal operation mode.
S D M
+
i
MENU
S D M
Figure 5-1
Switch the set to 'STANDBY', the error buffer will also be
cleared (by switching the set OFF-ON with the mains
switch, the set will come up again in the SDM).
By pressing the 'EXIT' button on the DST.
To perform alignments.
To change option settings.
To display / clear the error code buffer.
Software alignments (see chapter 8).
Option settings (see chapter 8).
Error buffer reading and erasing. The most recent error
code is displayed on the left side.
Operation counter.
Software version.
5.
GB 15
S D M
P I C T U R E
B R I G H T N E S S
S O U N D
C O L O U R
F E A T U R E S
C O N T R A S T
I N S T A L L
S H A R P N E S S
C O L O U R
T E M P
CL 06532130_010.eps
031000
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