Specifications
Service Modes, Error Codes and Fault Finding
GB 33EM3E 5.
Phenomenon Possible Cause Repair tip
No picture, no LED. Standby Supply defective. Measure circuitry (see diagram A2). Start at test-point A19.
When the Mains switch is ‘on’, this voltage must always be available
No picture, no LED. Bad connection of SSB in
SIMM-connector.
In case of a bad connection, it can happen that there is no picture, and that the
Standby LED is not controllable. Re-place the SSB.
No picture, red LED
blinking at 3 Hz.
Set is in protection due to
various causes. For error
codes see error-code list.
You have no picture, so:
- or you read the error buffer via ComPair
- or you read the blinking LED information via ‘diagnose’-‘x’-‘ok’ on DST
- or you read the error code sequence via ‘diagnose’-‘0’-‘ok’ with the DST.
When you have found the error, check the circuitry related to the supply voltage
and I
2
C-communication or the circuitry that triggers the protection.
No picture, red LED
blinking with code 6-6-6
or 18-18-18.
No communication on slow
I
2
C- or fast I
2
C-bus.
As processor cannot communicate with one of the 2 busses it the standby-led
spontaneously starts blinking 6-6-6… or 18-18-18….
If in the error buffer somewhere is an error 6 or 18, these will have the highest
priority starting the mentioned blinking.
Measure dependent of the error on the I
2
C-bus which device is loading the bus.
(use I
2
C -overview)
No picture, red LED
blinking with code 1-1-1.
No communication on NVM-
I
2
C bus to the µP.
As the µP cannot communicate with the NVM I
2
C bus, it spontaneously starts
blinking 1-1-1. Note: when there is no access to the NVM, a lot of picture
setting can go wrong.
No picture, no sound.
Set is making audible
squeaking sound
Supply is possibly in hiccup-
mode, which is audible via a
squeaking supply transformer.
Possible causes:
- V
BAT
is shorted (caused by short circuited line transistor 7421), or
- Sound winding is shorted (amplifier is shortening the power supply lines),
or
- D6514 is shorted (due to a too high V
BAT
).
Remove excessive load, to see what causes the failure, or check feedback
circuit. See repair tip ‘Main Power Supply’ (supply needs a minimal load).
No picture, no sound.
Green LED works fine
Supply does not work
correctly.
If e.g. V
BAT
is only about 90 V, it is possible that the regulator IC (7506) is
defective.
No RC-reception. Red
LED does not echo RC-
commands.
µP circuitry or RC-receiver is
defective.
In case the set does react on a local keyboard operation, you must check the
RC-receiver circuitry (diagram E).
Relay (degaussing) is
not audible, when set is
switched from ‘off‘ or
‘standby’ to ‘on’.
µP is not working correctly.
When pin 115 is low, the
degaussing must be
activated.
Check RESET-circuitry on diagram B5. Check the level on pin 115 when you
switch the set ‘on’. Signal must be low initially and go to high after approx. 12 s.
No sound, only picture. Measure A7/A8 on diagram
A1. Possibly the audio
amplifier is defect (but not
shorted), or the ‘sound
enable’ line is high (diagram
A5). Further, measure the
audio signal path (HIP-MSP-
Switch ICs-Amplifier).
In ComPair, a beep test can determine where the signal stops (use
loudspeakers or headphone).
Possible cause is also the ‘PROT1’ protection (see diagram. A6). This is a
loudspeaker DC protection, which the µP can not sense. Via circuitry
7701/7707, this signal can put audio amplifiers 7700 and 7702 in standby mode
(tri-state input). Warning: Find out, which amplifier is causing the problem,
because it is possible, that the other one is OK.
No sound at headphone
output.
HP amplifier (7770), or the
supply to it, malfunctions.
Measure test points A64 to A67, and the supply line (+/- 16/19V) on diagram
A7.
Picture is rotated. Rotation circuitry, or related
supply to it, malfunctions.
Measure test points A52 and A53 on diagram A5.
Picture is continuously
switching ‘off’ and ‘on’,
showing heavy ‘switch’
spots (set does not go
into protection).
200 V is missing on CRT
panel.
Probably a bad connection from LSP connector 1424 to CRT connector 1224
(diagram F), or an interruption of the 200 V supply line (e.g. R3341 is
interrupted).
Picture is not sharp. Focus is possibly mis-aligned
or SCAVEM-circuitry does not
work correctly.
Re-align the ‘focus’ potmeter on the Line Output Transformer, or check the
SCAVEM circuitry on the CRT-panel (diagram F). It is also possible that the
DAF circuitry is defective (see diagram I). Check the Vdc values.
Picture is not
synchronised.
The sync is derived in the HIP
from xtal 1305 and/or 1308.
Maybe the crystals 1305 and/or 1308 are making a bad contact.
Picture is distorted. Check video-path in Service
Default Mode.
Investigate whether there is an error code present in the error buffer. In case
there is one, check the I
2
C-bus and/or supply lines (see overview supply lines).
Measure and check signal path Tuner-HIP-PICNIC-HOP-RGB amplifier.
In case it is a geometry issue, check opto-coupler 7482, OpAmps 7440/7450
and the Frame circuitry alignments or a possible corrupted NVM (7011).
Picture with horizontal
stripes.
Feature box processing is
malfunctioning
Check functionality of PICNIC (7709), FALCONIC (7726) and/or field memories
(7714 and 7740). TS7726 and 7740 are suspected.
No menu, no OSD. Probably a defective µP. Measure test points B61to B64 on diagram B5.
No NextView (EPG). IC7012 defective or not
powered.
Check circuitry around IC7012.
No Teletext. IC7007 defective or not
powered.
Check circuitry around IC7007. Check also B61to B64 around µP on diagram
B5.
Strange switch ‘off’
behaviour
TS7445 possibly defective. Check, with a multimeter, whether transistor TS7445 is well functioning.
Various symptoms, due
to missing local supply
voltage.
An interrupted fuse, NFR-
resistor or connection.
When no symptom or error code leads you to a specific circuitry, use the supply
lines overview (see chapter 6), for a quick scan of all supply lines.
CL 16532044_039.eps
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