Service Modes, Error Codes and Fault Finding
EN 27EM5A P/M 5.
5.6 Blinking LED Procedure
5.6.1 Introduction
Via this procedure, you can make the contents of the error
buffer visible via the front LED. This is especially useful for fault
finding, when there is no picture.
When the SDM is entered, the front LED will show (blink) the
contents of the error-buffer. Error-codes = 10 are shown as
follows:
– A long blink of 750 ms (which is an indication of the decimal
digit),
– A pause of 1.5 s,
– 'n' short blinks (where 'n' = 1 - 9),
– When all the error-codes are displayed, the sequence
finishes with a LED blink of 3 s,
– The sequence starts again.
Example: Error 12 9 6 0 0.
After activation of the SDM, the red front LED will show:
– 1 long blink of 750 ms (which is an indication of the decimal
digit) followed by a pause of 1.5 s,
– 2 short blinks followed by a pause of 3 s,
– 9 short blinks followed by a pause of 3 s,
– 6 short blinks followed by a pause of 3 s,
– 1 long blink of 3 s to finish the sequence,
– The sequence starts again.
Note: If errors 1, 6 or 18 occur, the LED always gives the last
occurred error even if the set is NOT in service mode.
5.6.2 How to Enter
Use one of the following methods:
• Enter the SDM (only via soldering pads marked 'SDM' on
SSB). The blinking red front LED will show the entire
contents of the error buffer (this works in “normal
operation” mode and in “protection” mode).
• Transmit the commands 'MUTE' - '062500' - 'OK' with a
normal RC. The complete error buffer is shown. This works
only in “protection” mode.
• Transmit the commands 'MUTE' - '06250x' - 'OK' with a
normal RC (where 'x' is a number between 1 and 5). When
x= 1 the last detected error is shown, x= 2 the second last
error, etc.... This works only in “protection” mode.
5.7 Protections
5.7.1 Introduction
The EM5 has only one microprocessor (OTC), which remains
active during Standby. This because power of the
microprocessor and the attached memory chip set is coming
from the 3V3 supply, which is derived from the 5V Standby-
circuitry. So, in both Power-on as in Standby mode, the
microprocessor is connected to this power supply.
If a fault situation is detected, an error code will be generated
and if necessary, the set is put in protection mode. The
protection mode is indicated by the blinking of the red front LED
at a frequency of 3 Hz (or by a coded blinking in special cases).
In some error cases however, the microprocessor does not put
the set in the protection mode (this is the case with the -
hardware - loudspeaker protection of the audio amplifier).
The content of the error buffer can be read via the service menu
(SAM), the blinking LED procedure or via DST/ComPair. The
DST/ComPair 'Diagnose' functionality will force the set into the
“Service Standby”, which is alike the usual Standby, however
the microprocessor remains completely in normal operation.
To get a quick diagnosis, the EM5 has three service-modes
implemented:
• The Customer Service Mode (CSM).
• The Service Default Mode (SDM). Start-up of the set in a
predefined way.
• The Service Alignment Mode (SAM). In this mode, items
of the set can be adjusted via a menu and with the help of
test patterns.
You can enter both SDM and SAM modes via the “service
pads” on the SSB, via an RC-transmitter (DST or standard RC),
or via ComPair. It is not possible to enter the SAM in “standby”;
the TV has to be in “normal operation” mode.
The EM5 “Protection Diagram” shows the structure of the
protection system. See diagram below.
Figure 5-2 Protection diagram
There are several types of protections:
•I
2
C related protections.
• OTC related protections (via polling on I/O pins or via
algorithms).
• HOP related protections (mainly for deflection items).
• Hardware errors that are not sensed by the OTC (e.g.
vertical flyback protection, bridge coil protection, E/W
protection, arcing protection).
All protections are explained below.
5.7.2 I
2
C Related Protections
In normal operation, some registers of the I
2
C controlled ICs
are refreshed every 200 ms. During this sequence, the I
2
C
busses and the I
2
C ICs are checked.
An I
2
C protection will take place if the SDA and SCL lines are
short-circuited to ground, or to each other. An I
2
C error will also
occur, if the power supply of the IC is missing (e.g. FBX_PROT
(error 16)).
5.7.3 OTC Related Protections
If a protection is detected at an OTC input, the OTC will start to
scan all protection inputs every 200 ms for 5 times. If the
protection on one of the inputs is still active after 1 s, the µP will
put the set in the protection mode.
Before the scanning is started, a so-called “ESD refresh” is
carried out. This is done, because the interrupt on one of the
inputs is possibly caused either by a flash or by ESD. As a flash
or ESD can influence IC settings, the HOP, HIP, MSP, PICNIC,
XPR (43)
7301
7001
FLS (5)
HFB-XRAY-PROT
HOP
+8V SENSE (105)
+5V SENSE (106)
OTC
EHT-info
HFB
+5V_CON
+8V_CON
FLASH
DETECT
I
2
C
I
2
C PROTECTIONS
HIP
HOP
PICNIC
TUNER
NVM
DNR
MSP
TOPIC
I
2
C
I
2
C
PICNIC 3V3
TUNER
3D COMB*
FBX
PROTECTION
CL 26532041_081.eps
190402
LEVEL
DETECT
(* NTSC SETS ONLY)
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