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Philips EM1A Servise Manual Page 25

Colour television chassis.
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Phenomenon
Possible Cause
No picture, no LED.
Standby Supply defective.
No picture, red LED
There are 2 protections (which
(high intensity).
are not 'seen' by the processor)
Despite expectation,
that force the set in protection
the set should be ON
(after 5 restart attempts):
(this looks like
BRIDGE_PROT or MAINS DIP
Standby). After some
error.
time LED will start
blinking.
Set going into
180 V missing on CRT-panel
protection after 5
(diagr. F). Most probably R3341
restarts (error 7),
is interrupted, or RGB-amplifier
taking about 30 - 60 s.
IC7307 is defective.
No picture, red LED
Set is in protection due to
blinking (3 Hz)
various causes. For error codes
see error code list.
No picture, red LED
No communication on I
blinking (code 6, 6, 6)
('devices' bus) to processor. Set
is in protection-mode
No picture, red LED
No communication on I
blinking (code 10, 10,
('NVM' bus) to processor. Set is
10)
in protection-mode
No picture, no sound,
Supply could be in hiccup-mode
set is making audible
which can be heard via supply-
squeaking sound
transformer squeaking
No picture, no sound,
Supply does not work correctly
LED works fine
No RC5-reception.
Processor-circuitry or RC-
Red LED does not
receiver is wrong.
echo RC-commands.
Relay-activation
Processor not working correctly.
(degaussing) not
audible when switch
set on from off .
No sound, but picture.
Measure P7 on diagram A1.
Possible sound-amplifier is
defect (but not short-circuited),
or sound-enable line is high
(see diagram A5).
Further the audio-signal path
must be measured (HIP, MSP,
switch-IC s, amplifier).
No sound at
Discrete amplifiers or supply to
headphone output.
it could be damaged.
Picture is rotated.
Rotation-circuitry or supply to it
could be damaged (if present).
No picture.
Check functionality and cabling
Tuner to SSB.
Picture looks like
Or NVM-content is overwritten
cushion, further OK
or E/W-MOSFET is short-
circuited
Very white picture,
180 V is missing on CRT-panel
with flyback lines
visible
Un-sharp picture
Focus could be misaligned or
SCAVEM-circuitry does not
work correctly
Un-synced picture
Sync is derived in HIP-IC from
X-tals 1309 and/or 1310
Picture distorted.
Check video-path, service
default mode.
No menu, OSD.
Probably processor is defective.
Fault finding and repair tips
Repair tip
Measure circuitry (see diagram A2). Start at test-point P16.
Regardless the mode of the set, this voltage should always be available.
If protection is activated due to an absence of the Frame deflection, this
can be measured on test-point F10 (diagr. A4). Error 33 will be generated.
The BRIDGE_PROT could be triggered by an E/W failure.
An MAINS_DIP error (error 7) will be generated in both cases after 5
restart attempts, and will be visible via the blinking LED procedure.
ComPair is very useful here.
Measure 180 V behind R3341 (diagr. F) while operating, or measure
resistance of R3341 while set is of.
You have no picture, so:
Read out the error buffer via ComPair.
Read out blinking LED information via 'DIAGNOSE X' with DST.
When error is known, check circuitry related to supply voltage and I
communication.
2
C1-bus
Measure, dependent of the error, on the I
the bus. This protection can be overruled via SDM-entry (via short-
circuiting FRONT_DETECT to GND on Side I/O).
2
C3-bus
No contact of processor with the NVM. A lot of settings will therefore be
wrong.
This could be caused by:
Short-circuited V
BAT
Short-circuited sound-winding (amplifier is short-circuiting 28 V) or
Short-circuited D6514 (due to a too high V
Delete excessive load to see where failure is caused by or check feed
back circuit. See repair-tip main power supply (supply needs a minimal
load).
If e.g. V
is only about 90 V, regulator-IC 7506 could be damaged.
BAT
In case set reacts on local keyboard operation, error must be found in the
IR-receiver circuitry (diagram J).
Check RESET-circuitry on diagram B5. When switching on the set all I/o-
pins of processor should become high for a moment, so also the degauss-
input signal.
Measure and repair. With ComPair there is a beep-test that can determine
where the signal stops (use loudspeakers, headphone).
Measure A12, A13, A14, A15 and supply-line on diagram A6.
Measure test-points F3, R1, R2 on diagram A4.
Notice cable 1946.
First check in Service Alignment Mode, whether geometry can be
restored. If not check test point L4 and diagram A3, or measure with an
ohmmeter whether TS7480 is defective.
Probably R3468 on LSP (diagram A3) is interrupted, or bad connection
plug 0324 to 0224 (CRT-panel).
Align focus-potmeter of Line Transformer; check SCAVEM-circuitry on
CRT-panel [F].
Maybe an X-tal is making bad contact.
Investigate whether there exists an error code in the error buffer.
In case there is an error code, check I
overview supply-lines).
Measure and check signal path Tuner, HIP, PICNIC, HOP, RGB-amplifier.
In case it is a geometry-issue, check Frame-circuitry, alignments or
possible corrupted NVM (7012)
Measure test points C7, C8, C9, C10 on diagram B7.
EM1A
2
C-bus which device is loading
(caused by short circuited line transistor 7421) or
).
BAT
2
C-bus and/or supply-lines (see
5.
GB 25
2
C -
CL 06532111_057.EPS
121000

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