Hitachi C2117T User manual

HITACHI
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CAUTION:
Before servicing this chassis, it is important that the service technician read the
“Safety Precautions” and “Product Safety Notices” in this service manual.
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Data contained within this
Service manual is subject to
alteration for improvement.
* This Model has NO Production Plan - Circuits & Parts List are not included
in this Service Manual
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TECHNICAL SPECIFICATIONS Aerial input impedance 75 ohm unbalanced Picture tubes
2117. . bs hansen: .... 51 omtype
TV Standard .. ....-. 0.00 wes 625 lines, Programme Selectors 10 key buttons on the
C Models ...... .. .... .STANDARD I remote control, with UP/DOWN Mains Voltage .. ..... 220V~240V 50 Hz
CP Models...... .... .. STANDARD BG buttons on the front of TV
CS Models . .. STANDARD BG/DK FUSE bated ve eee TS. 1T5AL Type
All above 525 lines NTSC 4 43 MHz Power Consumption
DAVE seh. . 2 eh. Tees “SO VY Focusing Se. San et dads Electro static
Channel coverage .... . UHF Channels (UK)
UHF/VHF Hyper band (Export)
1997

SAFETY PRECAUTIONS
WARNING: The following precautions should be
observed .
1. Do not instail, remove, or handle the picture tube
in any manner unless shatter proof goggles are
worn. People not so equipped should be kept
away while picture tubes are handled. Keep the
picture tube away from the body while handling.
2. When service is required, an isolation transformer
should be inserted between the power line and
the receiver before any service is performed on
the chassis.
3. When replacing the chassis in the cabinet, ensure
all the protective devices are put back in place.
4, When service is required, observe the original
lead dressing. Extra precaution should be taken
to ensure correct lead dressing in the high
voltage circuitry area.
5. Always use the manufacturer’s replacement
component. Always replace original spacers and
maintain lead lengths. Especially critical
components are indicated thus A on the parts
list and should not be replaced by other makes.
Furthermore, where a short circuit has occurred,
replace those components that indicate evidence
of overheating.
6. Before returning a serviced receiver to the
customer, the service technician must thoroughly
test the unit to be certain that it is completely safe
to operate without danger of electrical shock, and
be sure that no protective device built into the
instrument by the manufacturer has become
defective, or inadvertently damaged during
servicing.
Therefore, the following checks are recommended for
the continued protection of the customers and
service technicians.
INSULATION
Insulation resistance should not be less than 10M
ohms at 500V DC between the main poles and any
accessible metal parts.
Also, no flashover or breakdown should occur during
the dielectric strength test, applying 3kV AC or
4.25kV DC for two seconds between the main poles
and accessible metal parts.
HIGH VOLTAGE
High voltage should always be kept at the rated value
of the chassis and no higher. Operating at higher
voltages may cause a failure of the picture tube or
high voltage supply, and also, under certain
circumstances could produce X-radiation levels
moderately in excess of design levels. The high
voltage must not, under any circumstances, exceed
29kV on the chassis.
X-RADIATION
TUBES: The primary source of X-radiation in this
receiver is the picture tube. The tube utilised for the
above mentioned function in this chassis is specially
constructed to limit X-radiation.
For continued X-radiation protection, replace tube
with the same type as the original HITACHI approved
type.
PRODUCT SAFETY NOTICE
Many electrical and mechanical parts in HITACHI
television receivers have special safety related
characteristics. These characteristics are often not
evident from visual inspection, nor can the protection
afforded by them necessarily be obtained by using
replacement components rated for higher voltage,
wattage, etc. Replacement parts which have these
special safety characteristics are identified by
marking with a A on the schematics and the
replacement parts list contained in this service
manual.
The use of a substitute replacement component
which does not have the same safety characteristics
as the HITACHI recommended replacement one,
shown in the parts list of this service manual, may
create electrical shock, fire, X-radiation, or other
hazards.
Product Safety is continuously under review, and new
instructions are issued from time to time. For the
latest information, always consult the current
HITACHI service manual. A subscription to, or
additional copies of HITACHI service manuals may be
obtained at a nominal charge from your HITACHI
SALES CORPORATION.
CE MARK
Some of these models may contain the CE mark on
the rating plate.
This illustrates that the T.V. contains parts that have
been specifically approved to provide
electromagnetic compatability to designated levels.
Therefore, when replacing any part in this T.V., please
use only the correct part itemized in the parts list of
this service manual to ensure this standard is
maintained.
Also, take care to replace lead dressing to its original
state, as this can also have a bearing on the
electromagnetic radiation/immunity.
TUBE DISCHARGE
The line output stage can develop voltages in excess
of 25k\V; if the E.H.T. cap is required to be removed,
discharge the anode to chassis via a high value
resistor, prior to its removal from the tube.

CIRCUIT DESCRIPTION
Tuner and I.F. Stages:
The tuner used on this chassis, is powered by the +5V
supply. The CP, CL and CS models cover the VHF-L, VHFH
and UHF bands whilst the ‘C’ models cover UHF only.
During tuning, the mark/space ratio output from pin 1 of
ICO001 changes. This is applied to the base of Q001 via
RO39, and the resultant voltage at the collector is filtered
and applied to the VT terminal of the tuner.
Signal recognition is performed by |C201 in conjunction with
IC001, and is explained later in the Remote Control and
Tuning Circuit description.
Band switching: CP and CS models
IC001 performs the necessary band switching in
conjunction with Q100.
“High” or “Low” outputs are obtained from pins 11 and 12
of 1C001, then applied to pins 3 and 4 of the tuner terminals.
These select the UHF or VHF-H bands.
When VHF-L band is selected, pins 11 and 12 of IC001
will both go “Low”. Q100 will then turn off, and
approximately +5v is applied to the VHF-L terminal of the
tuner via R106.
Therefore, which of the tuner terminals BU, BH, or BL has
a +5v applied to it depends on these “High” or “Low”
outputs.
UHF only: ‘C’ Models
A +5V is applied via R105 to the UHF (pin 3) terminal of the
tuner only.
The I.F. output from the tuner is applied to pins 45 and 46 of
IC201 via the SAW filter CP201.
Sound I|.F. stages: C and CP models
The sound stages consist of !C201, which basically
performs the required demodulation, and !C401, which is
the output amplifier.
The |.F. signal from the tuner is fed via saw filter CP201, and
applied to 1C201 at pins 45 and 46.
The composite signal available from pin 7 of I1C201 is
applied to the filter network of MF422, via L401A etc., then
fed to pin 5 of 1C201 via Q421 and C422.
Demodulation is then performed within the IC, with the
sound output being obtained from pin 50.
Sound I.F. stage: CS models
The sound stages consist of 1C4001, which performs the
change from |.F. to intercarrier, 1C201 which demodulates
the signal and !C401 which is the output amplifier.
The I.F. signal from the tuner is fed via the sawfilter MF4003,
and applied to IC4001 at pin 1.
The resultant intercarrier is available at pin 12 of IC4001 and
fed via the filter network consisting of MF422 (5.5MHz
intercarrier) and MF421 (6.5MHz intercarrier) and Q421 to
Pin 5 via C422.
Demodulation is then performed within the IC, with the
sound output being obtained from pin 50.
Audio
From pin 50 of !1C201 it is then applied to pin 3 of 1C401 via
Q401, C421 and R413, amplified, then output to the
speaker from pins 6 and 8.
Should C417 on pin 2 of 1C401 or its output go short circuit
the base of Q440 will become “Low”, and it will turn on. A
voltage will then be applied to the base of Q705, which then
turns off Q952, and as a result the +12v supply is removed,
thus preventing damage occurring to 1C401. How the +12v
is removed will be described in more detail later during the
horizontal circuit description.
Volume control is performed by the DC voltage applied to
pin 5 of IC201.
This is determined by the Pulse Width Modulated output
from pin 2 of IC001, which is then fed to IC201 after filtering
via RO17/R028 etc.
Under no signal conditions, or when the “SEARCH” routine
is initiated, pin 4 of 1C201 (ident) will go “Low”. When this
happens, internal circuits in |C201 prevent any sound
output from being obtained.
Demodulated sound is also available at pin 1 of IC201. It
is then connected to pins 1 and 3 of the 21 pin Euro
socket, via Q453 network for gain and impedance/level
matching.
If desired, this output can then be applied to external
equipment via an appropriate connecting plug.
Audio signals from external equipment can be applied to
the 21 pin Euro socket at pins 2 and 6 and these will be fed
via R403/R404 and C452 to Pin 6 of IC201.
Audio signals can also be applied to the front phono
sockets and these will be applied to pin 6 of IC201 via L151,
R406 and C452.
A separate switching voltage is also applied to pin 16 of
1C201 when external equipment is connected. The external
sound signal applied to pin 6 will then be switched to the
output of 1C201 {pin 50).
This is then further amplified by IC401, as previously
described.
Volume control of the external audio signal is obtained in the
same way as for internal sound, i.e., by the voltage level at
pin 5 of IC201.
(How the switching voltages are obtained for IC201, will
be explained in the Tuning and Contro! Circuit
description).
Vision I.F. Stages:
The |.F. signal from CP201 is applied to pins 45 and 46 of
IC201. These pins supply an internal amplifier consisting of
three stages whose gain is controlled by the A.G.C. circuit.
The speed of response from this internal A.G.C. stage is
determined by C205, connected to pin 48.
The output from the internal amplifier is then input to a quasi
synchronous demodulator stage, where the signal is
multiplied by its own carrier, i.e. the reference signal.
This reference signal is obtained from the input signal using
the tank circuitry of L202 etc. connected between pins 2
and 3 of the I.C.
The reference signal is limited by a clamping circuit, and is
then applied to the demodulator.
A control voltage from pin 47 of IC201 determines the RF
A.G.C. of the tuner.
The tuner take over point is determined by the voltage
applied to pin 49, which is governed by the setting of
VR202.
The composite video finally emerges at pin 7 of 1C201.
Luminance Circuitry
The composite video signal from pin 7 of |C201 via buffer
transistor Q501, is applied to the sound rejection filter
MF501, (6.0MHz, ‘C’ model) (5.5MHz CP and CS models)
and on the CS models there is an additional filter in parallel
with MF501 marked MF502 which is for frequency 6.5MHz
as this model has dual sound.

The resulting internal luminance signal is then applied to:-
a: Pin 19 of the Euro socket, from where it can be output to
external equipment if desired.
b: Pin 13 of 1C201 via Q301 buffer, for colour decoding and
deflection synchronisation.
c: Pin 23 of IC001 via RO68/RO69 divider network for TEXT.
The luminance signal is added internally to the RGB matrix
circuits of 1C201, and will be controlled by the brightness,
contrast, and blanking stages of the I.C.
The luminance signal finally emerges with the RGB signals
from pins 18, 19 and 20 of C201.
The voltages which contro! the contrast and brightness
levels are output from pins 5 and 6 of IC001, then applied
to pins 25 and 17 of IC201.
An automatic beam current limit circuit is employed on this
chassis. Should the beam current start to rise, the voltage at
pin 4 of the flyback transformer will fall. This fall is fed to Q752,
tuning the transistor on and pulling its emitter voltage low.
This fall in voltage is applied to pin 25 of IC201 via
D709/R723 and R527, effectively reducing the contrast
level, and hence the beam current.
Video signals from external equipment can be connected
to pin 20 of the 21 pin Euro socket where they will be
applied via Q460 and Q461 to:-
a: Pin 15 of 1C201 via C311.
b: Pin 24 of ICO01 for TEXT.
External video signals from the front phono socket can also
be applied via Q460 and Q461 to the above.
The switching voltage at pin 16 of |C201, ensures that only
the external signals are processed by IC201.
How the switching voltages are obtained will be explained
in the Remote Control and Tuning Circuit description:
Chrominance Circuitry:
1C201 is designed to demodulate PAL and NTSC. On CS
models an additional SECAM colour system is used.
On models operating in the PAL mode the demodulated
R-y and B-y colour signals are made available from pins
30 and 31 of 1C201, then fed to pins 14 and 16 of IC501,
which is a switch capacitor delay line.
The signals at pins 14 and 16 are clamped, then fed via an
internal buffer stage to delay lines, which are driven by a
clock signal of 3MHz to obtain a delay period of 64uS. This
internal clock is generated from a 6MHz voltage controlled
oscillator, and line locked by the sandcastle pulse input at
pin 5. Low pass filters after the delay line stages suppress
the unwanted clock signals.
The undelayed and the delayed signals are then added, with
the resulting R-y and B-y signals being output from pins 11
and 12. These are then fed to IC201 at pins 28 and 29.
IC201 contains clamping circuits, and a DC colour
saturation control, the level of which is set by the voltage
applied to pin 26 from pin 4 of ICO01. The signals are then
applied to a MATRIX circuit, and finally emerge from pins
18, 19 and 20 as the blue, green, and red signals.
On models (CS) capable of receiving SECAM
transmissions, the R-y and B-y signals from pins 30 and 31
are also connected to pins 9 and 10 of IC502. This IC will
then produce control voltages from pins 1 and 16. These
are applied to pins 32 and 27 of IC201, and condition the
|.C. to process the SECAM signals, thereby producing blue,
green, and red outputs from pins 18, 19 and 20. The
sandcastle pulse is also connected to pin 15 of IC502 to
control its operation.
If NTSC signals are received on a CS model pin 34 (R
model), pin 30 (T model) of |C001 goes “low”. This turns
Q014 off, which then causes Q013 to turn off, and the
voltage level at pin 27 of IC201 will fall to a voltage
between 0-5V originating from the hue control, pin 3 of
IC001 via RO63, RO78, R116 and L052.
If now the signal received is SECAM or PAL the reverse will
occur finally leaving pin 27 of IC201 high with a voltage of
approximately 6V.
For C and CP models pin 27 is held at 3V by the divider
network R528/R529 for PAL and NTSC reception with fixed
hue setting for NTSC.
Remote Control and Tuning Circuitry:
The remote control receiving unit U001, contains an infra
red amplifier. This is powered by the standby +5v supply,
which is obtained from the +12v supply via Q957, and
stabilised by ZDO06.
The output from pin 3 of the infra red amplifier is applied to
pin 35 of ICO01 (‘R’ models, non text), pin 45 of ICO01 (‘T’
models).
This I.C., performs channel selection, UP/DOWN analogue
control, on-screen display, search tuning, and also controls
inputs and outputs to and from the external input sockets.
IC002 is the memory |.C., which stores all data relating to
the above functions, then transfers that information to
IC001 when required.
IC001 and IC002 are both powered by the standby +5v
supply.
X001, C026 and C027, connected between pins 31 and 32
(‘R’ models) or pin 41 and 42 (‘T’ models) supply |CO001 with
a basic clock frequency to control all operating mode
requirements.
IC001 must be initially reset from switch on, and this is
achieved by Q004.
As the +5v supply begins to rise from switch on, pin 33 (R’
models) or pin 43 (‘T’ models) of IC001 is held “High” via
R075, thus resetting the I.C.
The “High” is removed from this pin when C002 becomes
charged via RO15 and DOO3, causing Q004 to switch on,
thus releasing the reset condition.
When the search routine has been initiated and a signal has
been located, pin 4 of 1C201 will become “High”. This is
applied to pin 41 (‘R’ models) or pin 5 (‘T’ models) of
‘(C001’ and informs the I.C. that a signal is present.
The search routine then stops, and the I.C. will monitor the
AFC signal present at pin 9 to obtain the optimum signal.
Contrast, colour, brightness, hue, sharpness and volume, are
all controlled from the remote contro! handset (can also be
adjusted by the + and - buttons on the front of the T.V.), and
will produce DC level changes from pins 2 - 7 of |C001. These
changes are then applied to the relevant pins of IC201.
Pins 36 to 38 (‘R’ models) or pins 46 to 48 (‘T’ models) form
the in and out matrix for the front control operations.
Pins 39 to 40 (‘R’ models) or pin 49 and 50 (‘T’ models)
provide clock and data information. These are connected to
the memory IC002. ,
When external equipment connected to the 21 pin Euro
socket is turned on, +12v is output from pin 8 of the socket
to DOO6. The diode then becomes forward biased, and
applies approximately +5v to pin 10 of ICO01 via potential
divider RO35, RO36.
From pin 15 of IC001 an output, “high” is then applied to
the base of Q007 turning it hard on and pulling its collector
“low”. As a result Q005 will turn off, thereby supplying
approximately 8V to pin 16 of |C201 via the potential divider
network of RO24/R103.
This ensures IC201 will process only the external inputs
applied to pins 6 and 15.
If the external equipment does not have an equivalent 21
pin Euro connector, or if the external inputs are applied via
the phono sockets on the front of the T.V., then the AV

button on the remote contro! has to be pressed to select
the external mode. This will then produce the required
“High” from pin 15 (ICQ01) to achieve the necessary
switching voltages.
When a command requiring an on-screen display is
received by |C001, a”High” is made available at pin 25 (‘R’
model) pin 35 (‘T’ model).
This is applied via DO39A to pin 21 of IC201, and blanks out
a portion of the picture. The on-screen display information
is then inserted into this portion, thus resulting in a clear
display.
‘R’ models
The components L024, C024, and C013, on pins 28 and 29,
determine the display oscillator frequency, whilst the
horizontal and vertical inputs at pins 26 and 27 determine
the actual position of the on-screen display.
‘T’ models
The character display is generated from the text
character set, whilst the horizontal and vertical inputs at
pins 36 and 37 determine the actual position of the on
screen display.
Timer and Standby
When the “OFF” timer mode has been set, and the time
input has elapsed, pin 20 of IC001 outputs a “Low”. This
removes the drive supplied to the base of Q952, and as a
result the +9v supply from IC951 disappears. This places
the T.V. into its standby mode of operation by shutting
down the E.H.T. generation stages of 1C201.
Also, pin 19 of !C001 is taken ‘low’ causing the illumination
level of DOO1 to increase.
This sequence also applies when putting the TV into
standby mode via the handset.
Deflection Circuits:
The deflection circuitry of |1C201 contains a sync. separator
stage, horizontal oscillator and output stages, a vertical
countdown and output stage.
Horizontal Stage:
An internal composite video signal from pin 7 of IC201 is
returned to pin 13 or an external signal from the 21 pin Euro
socket is applied to pin 15 of |C201 as previously explained.
One of these inputs, pin 13 or 15 via the internal/external
switch of IC201 is applied to the internal sync. separator
stages of the IC.
An internal phase detector stage is provided with a
sawtooth waveform, generated from the line pulse input to
pin 38. The phase detector then compares this sawtooth
waveform to the sync. pulse.
Should any frequency drift occur, a corrective output will be
applied to the horizontal oscillator, thereby maintaining the
desired phase relationship.
The components connected to pin 40 form a filter network
for the phase detector, and VR701 connected to pin 39
provides manual phase control.
The horizontal output emerges at pin 37 and is then applied
to the base of line drive transistor Q701.
T701 couples Q701 to the line output transistor Q702. Both
these transistors are powered by the +B (H.T.) supply.
A line pulse available at pin 1 of the flyback transformer is
rectified by D701, smoothed by C716, and provides
approximately 200v to drive the video output transistors
Q801, Q802, and Q803 on the C.R.T. base.
Under certain fault conditions, i.e. increased H.T. supply, or
low line oscillator frequency etc., an excess of E.H.T. could
be developed.
To prevent this happening, the rectified voltage of D701 is
fed via potential divider R715, R716, and applied to pin 3 of
the comparator 1C701. Should the E.H.T. rise excessively,
the voltage level at pin 3 of IC701 will exceed the threshold
level determined by ZD704 (5v1 Zener) at pin 2.
When this happens, the output at pin 1 of IC701 becomes
“High”, causing Q705 to conduct and pulling pin 20 of
IC001 low. After a short period of time, the low at pin 20 of
IC001 causes the |.C. to latch into its standby mode, and a
“Low” will be applied to the base of Q952, turning the
transistor off.
Consequently, Q953 is turned off, and the +9v supply to
IC201 will be removed, thereby shutting down the
deflection stages of the |.C. and preventing further E.H.T.
generation.
Excessive beam current can also occur under certain
fault conditions, so this is prevented in the following
manner.
The H.T. current to the horizontal output stages is
measured by R727.
Should the current rise, the increased voltage drop across
R727 will cause Q704 to be turned on, and a voltage will be
applied to the base of Q705 via R729.
This will then prevent further E.H.T. generation as previously
described.
Vertical Stages:
The internal vertical sync. of [C201 is fed to a triggered
vertical divider stage, which counts down the horizontal
frequency to obtain the vertical frequency. This eliminates
the need for a conventional oscillator circuit, and has the
added advantage that no external frequency control is
required.
C601/C601A at pin 42 of the I.C. are used for ramp
generation, producing the required sawtooth.
The vertical output from pin 43 of 1C201 is applied to pin
4 of 1C601 via R604. The components D601 and C605
determine the flyback generation time, and the vertical
output to drive the deflection coils is made available from
pin 2.
A supply of +25v is required for |C601. This is obtained from
pin 6 of the flyback transformer, rectified by D702/D702A,
smoothed by C719, then applied to pin 6 of IC607.
The deflection current that occurs at the junction of
C609/R609 is added to the feedback from R607/C608 etc,
and the result is applied to pin 41 of IC201. The values of
R607 and C608 determine the linearity, whilst VR601 sets
the vertical height.
When the 16:9 ratio format is selected, a “High” is made
available from pin 16 of 1C001. This is applied to Q015 via
R121, turning the transistor off.
This effectively removes R125 from pin 42 of 1C201, thus
reducing the current and changing the vertical ramp output.
In this way, the vertical height is corrected to suit the 16:9
wide screen format.
Power Supply Circuit:
The AC input is rectified by D901 - 04, and produces
approximately 300v at the collector of Q903.
Current flowing through R901, causes Q903 to initially turn
on.
Secondary voltages are then induced in T901, and a
feedback voltage is obtained via D905, L903 etc., and
applied to Q903 base, maintaining the transistors
operation.
This circuitry self oscillates at a frequency determined by
the inductance of the transformer, the AC mains voltage,
and load conditions etc.

The secondary voltage induced in the S1 - S2 winding is
rectified by D951 to produce the +B (H.T.), which is
smoothed by C952.
The S3-S4 winding produces +12v via D952, and this is
smoothed by C954.
It is then applied to Q953, and in conjunction with IC951
produces the chassis +9v supply.
Q951 stage controls the H.T. regulation.
The base of Q951 is set to a pre-determined level by the
resistor network R952, VR951, and R951.
Should the H.T. rise, the base current fed to Q951 will
increase, turning the transistor on harder. This causes more
current to flow through the opto-coupler IC901.
An output is then produced from pin 5 of the opto-coupler,
which is applied to the transistor network Q901, Q902.
As these transistors control the on time of the power
transistor Q903, a constant and regulated H.T. level is
maintained.
ZD952 offers protection to the H.T. circuits should the
voltage level rise excessively.
When the standby mode is selected, pin 20 of I1C001 will go
“Low”, removing the drive to Q952.
As a result, Q953 is turned off, and the +9v to IC201
disappears, therefore shutting down the deflection stages
of the 1C201. E.H.T. generation will then cease for as long
as the standby condition exists.

PICTURE AND CONTROL ADJUSTMENTS
H.T. Adjustment (+B):
1. Switch TV. on, receive Philip’s circle test pattern, and set contrast and brightness levels to maximum.
2. Connect a voltmeter between the +ve leg of C709 and Ground.
3 Adjust VR951 so that meter reads as follows:-
51cm models 112v + Ov2
A.F.C. Alignment: (L202 Adjustment)
1 Switch on the TV. and apply an I.F signal (88 9MHz) with a level between 10 and 0 dBm, to pin 1 of CP201
2 OnCS models only, set the standard selection to AUTO in the Installation menu. (see operating guide for Installation menu examples).
3 Connect an oscilloscope and a voltmeter to pin 44 of IC201.
4, Adjust L202 until fast rate of change is seen on the oscilloscope, then carefully adjust L202 until voltmeter reads 4 Ov + 0.2v
AGC Adjustment:
1. Switch TV on and allow to warm up for at least two minutes
2. Receive a signal with a level of -47dBm
3 Connect a voltmeter to the AGC terminal of the tuner unit.
4 Adjust VR202 until meter reads 2v5 +/- Ov2
Horizontal Phase/Vertical Centre/Vertical Amplitude:
Receive Philip’s circle test pattern.
Set brightness and contrast levels to maximum, then face the television to the North or South.
Adjust VR701 to centralise circle pattern.
Connect the removable plug on E601 to the pins which achieve the best vertical centre position.
Adjust VR601 to obtain the required vertical height
Return brightness and contrast levels to their previous levels
AARON
Focus Adjustment:
1. Receive Philip’s circle test pattern setting colour level to minimum, and contrast and brightness levels to maximum
2 Adjust contrast so that the first two bars of the colour bar display become black
3. Adjust brightness so that the 3rd and 4th bars of the grey scale bar display are the same colour black as in step 2
4 Adjust the focus control (upper control on flyback transformer) to obtain the best overall focus.
COMPOSITION OF TEST CARD PROVIDED BY PHILIPS PM5644 COLOR PATTERN GENERATOR
Colorless (R Yb signal Border castellations for check of picture Colorless (8-Y) signal
for check af decoding centre and atpact ratia for check of decoding
Cigitally derived circle
for chack of scanning linearity
ou
E
Burst
gata —>
check
250 kHz squarewave of 75% contrast
white and black refarence level for calor bar
NS
NS
SS
NWN
AVG
g g<
ERG
Check of
subcarrier
jockin:
N
NXVL QV QR MAR EAS NN
Color difference signats Color ditterance signals
for check of decoding for check of decoding

CUT OFF AND SCREEN ADJUSTMENT
PREPARATION
(i)
(ii
Preset the red, green and blue background controls on the C.R.T. base to the positions shown. (Approximately mid. point).
Component Side
Set the customer controls as follows:- Contrast = 0
Colour = 0
Brightness = middle of scale
(iii) Receive horizontal white line, or red raster pattern from a Philip’s pattern generator.
METHOD:
1.
Adjust screen control (lower control on the flyback transformer) until the horizontal line is just visible and its colour can be
seen.
2. Do not touch the background control of the colour that is most prominent on the screen, but adjust the other two
background controls until a reasonable white line is obtained
Connect an oscilloscope probe to each of the R.G.B. cathodes in turn and leave connected to the one with the highest level.
4. Set customer brightness so that the cathode value is no greater than 140v as shown below.
Peak white wow... : si wee veoevand AAOV
5. Disconnect oscilloscope, and set screen control so that the white horizontal line is just visible once more.
WHITE BALANCE
PREPARATION:
(i)
(ii)
Set the customer controls as follows:- Contrast = 0 Colour = 0
Receive the white raster pattern.
(iii) Obtain and set up a combined colour analyser and light meter, e.g. MINOLTA CA100.
METHOD:
1.
Adjust brightness customer control so that the light output from the white raster reads Y = 1 — 2 cdm’* on the light
meter.
Next adjust the red and blue background controls to obtain the colour chromaticity co-ordinates of x = 283 y = 299
representing a colour temperature of 9300k (models C, CS and CP/481/381).
For colour temperature of 7400k the red and blue background controls will have to be adjusted to obtain the colour
chromaticity co-ordinates of x = 304 y = 320 (for all CP models other than shown above).

PROTECTION CHECKS
High Voltage Limit Check:
1.
2.
Switch T.V. on and set contrast and brightness levels to maximum.
For models 34cm and 41cm, connect a 1M4 resistor in parallel with R715 and ensure that the picture and sound disappear
instantly.
N.B. On 51cm models, resistor value should be 1MO and on 59cm models it should be 1M2.
Switch T.V. off, remove resistor, and wait 10 ~ 15 seconds.
Switch T.V. on again, check that normal operation is resumed, then return contrast and brightness levels to their original
levels.
Anode/Focus s/c Check:
1
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Switch T.V. on and set contrast and brightness levels to maximum.
Connect a 270R (20 - 30 Watt) resistor from pin 9 of the flyback transformer to ground.
N.B. Use a 470R resistor for 51cm/59cm models.
Check that picture and sound disappear instantly.
Switch T.V. off, remove resistor, and wait 10 - 15 seconds.
Switch T.V. on again, and check that normal operation is resumed, then return contrast and brightness levels to their
original levels.
POSITION OF ADJUSTMENT CONTROLS
ON/OFF switch
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VOLTAGE MEASUREMENTS
IC001 P83C055 (‘R’ models)
PIN VOLTAGE PIN | VOLTAGE
IC002 ST24C04
PIN | VOLTAGE
en voce
1 varies with tuning 1
2 OV-5v (varies with volume) 2
3 Ov-5v (varies with hue) 3
4 Ov-5v (varies with colour) - 4
5 Ov-5v (varies with contrast) 4v8 5
6 Ov-5v (varies with brightness) 4v5 6
7 Ov-5v (varies with sharpness) 2v8 ig
8 not used 2v8 8
9 1.8v not used
Ov (5v0 with direct scart input) 2v5
Ov VHF-L and VHF-H (5v0 UHF) 3v0
Ov VHF-L and UHF (5v0 VHF-H) Ov eee tune
OV 1v1 (5v0 NTSC signals) PIN
OV (1v7 RGB mode) 5v0
Ov (5v2 AV/RGB modes) 4v5 1
Ov (5v0 16:9 selection) 4v7 2
Ov (Ov7 system L’) 5v2 3
Ov (6v0 system L) 5v2 4
3.4v (Ov in standby mode) 5v2 5
3v8 (Ov in standby mode) 5v5 6
Ov 5v0 Fé
8
9
IC001 SAA529X
PIN VOLTAGE PIN VOLTAGE PIN VOLTAGE
‘ varies with tuning 3v4 (Ov in standby mode)
2 OV-5v (varies with volume) 3v8 (Ov in standby mode)
3 Ov-5v (varies with hue) N/C
4 Ov-5v (varies with colour) Ov
5 Ov-5v (varies with contrast) 2v7
6 Ov-5v (varies with brightness) Ov6
rf Ov-5v (varies with sharpness) 2v3
8 Ov (B6) 5v (Dk) 2V6
9 1.8v Ov
Ov (5v0 with direct scart input) Ov
Ov VHF-L and VHF-H (5v UHF) N/C
Ov VHF-L and UHF (5v VHF-H) 1v1 (5v NTSC Signals)
OV 4v7
OV (1v7 RGB mode) Ov
Ov (5v2 AV/RGB modes) Ov
Ov (5v0 16:9 selection) Ov
Ov (Ov7 system L’) Ov
Ov
IC201 TDA836 1 AND 2
VOLTAGE PIN | VOLTAGE PIN | VOLTAGE VOLTAGE
IN
14 3v0 27 | 8v0 (0-5v NTSC signals)*| 40
15 4v2 41
16 | Ov (7v8 AV/RGB mode) 42
17 3v0 43
18 2v0 44
19 2v0 45
20 2v1 46
21 Ov3 47
22 3v4 48
23 3v4 49
24 3v4 50
25 2v3 51
26 1v2 52
OONOORWDNM —
NOTE: Pins 5, 17, 25, and 26 will vary depending on the level of brightness etc. set by the customer. Pin 27 is the Hue control
in NTSC signals.
* ALSO PAL FOR C & CP MODELS
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