The SERVICE MODE screen is entered by
pressing the ‘ESO’ button underneath the cover
on the handset. The T.V. must, however, be in
factory mode first. The T.V. can be switched into
factory mode by pressing both VOLUME +/buttons on the front of the set whilst it is
powering up.
1) The Version number of the programme code
in the EPROM is displayed after the word
“CODE”.
2) The Version number of the data in the
external EEPROM (E2) is displayed after the
word “E2”.
AFC INDICATION
The service engineer can set the AFC coil ([202)
without the use of a meter by ensuring that the
AFC digit is on the boundary between 2 and 3.
The range of the digit is between 0 and 4.
A2 ADJUSTMENT
1) The A2 input level can be adjusted to any
desired value between 0 and 15 by using the
cursor LEFT/RIGHT buttons on the handset.
The normal value is 0.
2) The A2 Stereo separation can be adjusted to
any desired value between 0 and 63 using the
cursor LEFT/RIGHT
00RED Gain
01GREEN Gain
02BLUE Gain
03RED Level
04GREEN Level
05BLUE Level
NOTE: These adjustments are for the current
selected white balance setting in the FEATURE
MENU. The user will have to swap between the
FEATURE MENU and SERVICE MODE to
adjust all 3 white balance settings (COLD,
NORM and WARM).
SERVICE BYTE DESCRIPTION
Factory AutoIDolby TOPSingleNOTComb
Mode Tuning Standard Disable TextStandard USEDFilter
ONONVHFEnableEnableEnable
OFF
NOTE 1: The user can NOT alter the FACTORY
MODE or AUTO TUNE flags using the left/right
cursor buttons on the handset when in SERVICE MODE.
Main A5 Menu Tree
A5 Sub-Menu Tree
Service Mode Menu Tree
Fig. 1
Fig. 2Fig. 3
Specifications / Safety Parts / Menu Trees / Service Mode / Service Mode Cont’d / Text Diagram / Voltage Tables / Voltage Tables Cont’d / 16:9 Deflection PCB
Signal Processing (C2576/77TN - 311, CP2576TAN-301/351, CP2576TAN-331/381) / Signal Processing Diagram (CL2576, CP2576, CL2976, CP2976, C2976TA, C2975TAN, C2976TN)
Page 2
HITACHI C2576 TN
2
Service Mode Cont’d
NOTE 2: The Factory Mode flag is set to ‘1’
when the T.V. is in Factory Mode. Factory mode
can be entered by pressing
both VOLUME +/- buttons on the front of the set
whilst it is being powered up.
NOTE 3: Auto Tune can be enabled so when the
TV. is switched on, it will start tuning in the TV.
(after the user has gone through the INSTALLATION MENU). This flag is enabled when the
user presses the STANDBY button or switches
the set off when the AUTOMATIC TUNING
screen is displayed.
NOTE 4: The I Standard VHF disable flag
informs the TV. whether or not it should begin
tuning at 441.10 MHz or 41.10 MHz. If this is set
then tuning will begin at 41.10 MHz. If this is ‘0’
and the single standard flag is ‘1’, then tuning
will begin at 441.10 MHz instead.
NOTE 5: For the A5 75 Model Range of T.V’s,
this flag will be set to indicate to the software
that no Dolby board is present.
NOTE 6: For sets that should have TOP TEXT
available, the TOP TEXT ENABLE flag should
be set to ‘1’.
NOTE 7: For a single standard chassis
(CP****TA, CP****TAN, and C****TN) this flag
should be set to ‘1’.
NOTE 8: For AS 25” and 28” models, the COMB
FILTER will not be fitted and as such this flag
should be cleared to ‘0’.
The GEOMETRY, GREY SCALE, A2, and
SERVICE BYTE values can be stored by
pressing the MENU button whilst the
SERVICE MODE screen is displayed. If the
user makes any mistake, the T.V. ( ) button
can be pressed to clear the screen. The
“ESC” button can then be pressed to reenter SERVICE MODE again.
A5 CHASSIS ALIGNMENT PROCEDURE
1. APPLICATIONS
2. P. W.B. ASSEMBLY ADJUSTMENT
2.1 FOR SIGNAL
2.1.1 PREPARATION ADJUSTMENT
2.1.2 AGC ADJUSTMENT
2.1.3 AFC ADJUSTMENT
2.2 FOR POWER AND DEFLECTION
2.2.1 +B VOLTAGE ADJUSTMENT
2.2.2 POWER GOOD LINE
2.2.3 AUDIO FEEDBACK TRIM
2.2.4 HIGH VOLTAGE LIMITER CIRCUIT CHECK
2.2.5 ANODE/FOCUS SHORT-CIRCUIT
TEST PROTECTION CIRCUIT
2.2.6 SUB PSU +9.5 V VOLTAGE SET
2.2.7 BASIC TEST SPECIFICATION
2.2.8 PRIMARY CURRENT LIMIT (C28300
ONLY)
3. FINAL ALIGNMENT
(BY SOFTWARE ADJUSTMENT)
3.1 PICTURE POSITION/SHAPE
3.1.1HORTZONTAL
VERTICAL CENTRE
VERTICAL AMPLITUDE
3.1.2TILT
PARABOLA
WIDTH
3.2 FOCUS ADJUSTMENT
3.3 SCREEN CONTROL/CUT OFF ADJUSTMENT
3.4 WHITE BALANCE ADJUSTMENT
4. PIN P ADJUSTMENT
5. ADJUSTMENT POINTS
6. SERVICE BYTE ASSIGNMENT INFORMATION
1. APPLICATIONS
THIS SPEC. SHOULD BE APPLED TO C2576/
77TN AND C2876/77TN (28300)
2. RW.B ASSEMBLY ADJUSTMENT
2.1 FOR SIGNAL
2.1.1 PREPARATION ADJUSTMENT
1) +B adj. VR950 .... Centre
2) Screen VR (FBT) .... Counter-clockwise fully
3) Turn on set. Adjust +B to approximately
150V. (Pre adjustment only - full adjustment in
section 2.2.1)
2.1.2 AGC ALIGNMENT
1) With the signal received, apply heat run for
more than two minutes to avoid the influence
of circuit temperature drift.
2) Connect a voltmeter of at least 100K internal
resistance to the A.G.C. terminal of the tuner.
3) Receive the channel below.
4) Adjust A.G.C. potentiometer VR201 until the
following voltage is obtained.
2.1.3AFC ALIGNMENT
L202 ALIGNMENT
1) apply relevant RF signal. Circle Pattern
2) on dual/multistandard receivers select BG
standard.
3) Enter frequency on CTV controls to ensure
AFC loop is off.
4) Connect oscilloscope and voltmeter to pin 23
IC201 (TDA9815) or pin 13 (TDA9800).
5) Adjust L202 until fast rate of change is seen
on the oscilloscope.
6) Adjust L202 so that the voltmeter reads 2.5V
0.2V.
VR202 Alignment (CL**76/77TAN only)
1) Apply L standard RF signal.
2) Select L standard on CTV controls (system L
VHF band 1).
3) Enter frequency on CTV controls.
4) Connect oscilloscope and voltmeter to pin 23
IC201.
5) Adjust VR202 until a fast rate of change is
seen on the oscilloscope.
6) Adjust VR202 so that the voltmeter reads
2.5V ± 0.2V.
2.2 POWER AND DEFLECTION ADJUSTMENT
2.2.1 +B VOLTAGE ADJUSTMENT
1) AC input voltage = 230V + SV/5Hz.
2) Turn +B voltage VR (VR950) to mid-point (if
pre-adjustment not done).
3) Receive Philips circuit pattern. Switch on
chassis and set the brightness and contrast to
maximum.
4) After applying heat run for 30 sec. or more,
turn VR950 gradually and adjust +B (re-check
after 2 minutes heat run).
Measuring point: +B voltage C955 + side
gnd C955 - side
5) Set the value of +B voltage to the value
shown in the following table.
6) Short circuit test (all rails). PSU should go
into standby/reset/lockup. (Supply may have
to be removed to restart)
7) Standby check. +B should go to 120V < +B
>140V. ±8, +5, +12V should be 0V.
2.2.2 POWER GOOD LINE
1) Set picture to same conditions as above.
2) Measure pin 1 PL9S1. Should be HI, if LOW
then cut R945 (if fitted). If HI but no power
down timing (see below) then cut R991.
3) Check power down logic timing (>5mS).
2.2.3 AUDIO FEEDBACK TRIM
(For sound on vision)
If sound on vision is seen with maximum bass 1/
2 volume on normal Picture - STEREO Sound
then cut trim resistor R969A (to change R969
value to 22K)
2.2.4 HIGH VOLTAGE LIMITER CIRCUIT
CHECK
1) Mount the PW board to the set and adjust
normally.
2) Receive the circle pattern signal.
3) Set the contrast and brightness to maximum.
4) Add R=470K in parallel with R718 and R749.
5) Check that picture and sound disappear when
R is added.
NOTE: High voltage limiter circuit jig:
25”29”
R718229K 240K
R74947K4K7
R7193K356K
To comparison circuit 10953 (Protection)
2.2.5 ANODE/FOCUS SHORT-CIRCUIT TEST
PROTECTION CIRCUIT CHECK
1) Receive the circle pattern signal.
2) Set the contrast/brightness to maximum.
3) Check trip point by adding an external D.C.
supply across R730. The set should not trip
when a 0.8V supply is added. The set should
trip when a 1 .2V supply is added.
2.2.6.SUB POWER SUPPLY ADJUSTMENT
1) Switch on power supply (mains input 230V ±
5V 50Hz).
2) Measure +9.5V output. If output is greater
than 9.8V then cut R9107 (220K 1/4W).
3) Re-check +9.5V output: output must be +9.5V
± 0.3V.
2.2.7.SUB POWER SUPPLY TEST
Test for:
TEST SPECIFICATION
+9.5V+26V
1) Load regulation+9.5V + 0.3V +26V+4V-1.5V
- 0.7V
2) Voltage regulation+9.5V + 0. 3V +26V+4V-1.5V
- 0.7V
3) Ripple voltage300mV400mV
(at 200V VAC IN)
4) Short circuitNo FailureNo Failure
+9.5V and +26V
5) Standby (all rails should0V0V
be at 0V
6) Remote on/off operation Hi/Low Hi/Low
TEST LOAD
+ 9.5V+ 26V
Max200mA2A
Min50mA0.1A
2.2.8.C28300 POWER SUPPLY SETTING
(MAIN BOARD)
1) Connect DVM to +B line.
2) Adjust ac. mains input to 190V a.c.
3) Adjust VR923 and VR950 to mid-point
positions.
4) Turn TV on and adjust VR950 until +B is as
per table below.
5) Switch TV into standby.
6) Connect load A across C955 and load B
across C967.
7) If set trips out with loads A and B then go to
step 8, if not, then adjust VR923 clockwise
until TV shuts down.
8) Disconnect a.c. mains input and loads A and B.
9) Connect load C across C955 and load D
across C967.
10) Connect a.c. mains input.
11) If P.S.U. remains operative when switched
on with loads C and D connected then
alignment is correct.
12) If P.S.U. shuts down then alignment is
incorrect. (Adjustment complete).
13) Disconnect a.c. mains input and loads C
and D. Adjust VR923 to mid. point position
and proceed from step 5.
3.1.1 HORIZONTAL PHASE, VERTICAL
CENTRE, VERTICAL AMPLITUDE
1) Wait 5 minutes minimum after switching on
the mains before adjustment.
2) Receive the Philips circle pattern.
3) Set brightness and contrast to maximum.
4) The set should face North or South.
5) AC input should be 230V ± SV 50Hz.
6) Adjust software control in service mode using
appropriate controls.
7) Adjust control so that the centre of the picture
is as in the diagram below.
3.1.2 TILT, PARABOLA, WIDTH.
1) Allow 5 minutes warm up time before
adjustment.
2) Receive Philips circle pattern.
3) Set brightness and contrast to nominal.
4) The set should face North or South.
5) AC input should be 230V ± 5V 50Hz.
6) Adjust software in service mode using
handset so that the vertical lines at the
outside edges of the screen are adjusted to
be roughly vertical.
7) Adjust the software in service mode using
handset so that the (approximately) vertical
lines at the sides of the screen are adjusted
as vertical as the centre of the screen.
8) Adjust the software in service mode using
handset so that the castillations at the sides
of the picture are not quite visible. Reduce the
brightness and contrast to make sure that the
picture width has not reduced so that you can
see beyond the castellations. You may have
to repeat stages 6 and 7 again.
3.2 FOCUS ADJUSTMENT
1) Receive the Philips circle pattern.
2) Adjust after horizontal/vertical has been
adjusted.
3) Switch the received signal to the cross hatch
signal.
4) Turn the focus VR gradually clockwise from
the full counter clockwise position so that the
focus of the vertical line in the centre part,
furthest to the right is adjusted for best result
(contrast - maximum, brightness - normal).
3.3 CUT-OFF ADJUSTMENT
1) Rough adjustment.
(1.1) Set to video mode with no signal.
(1.2) Turn screen pot of FBT until flyback lines
disappear.
2) Fine adjustment
(2.1) Set contrast to mm, brightness to mid,
colour to mid.
(2.2) Receive cross hatch pattern.
(2.3) Connect probe to CRT green cathode.
(2.4) Adjust screen pot until black level is 170V
(29”) 160V (25”).
3.4 WHITE BALANCE ADJUSTMENT
(After cut off set correctly)
1) Set white balance to ‘Norm’ in picture
(enhanced features menu).
Contrast - Minimum
Brightness - Mid. Point (fine adjust using
colour analyser)
Colour - Mid point
2) Adjust red and blue level registers of
TDA4780 to get correct low light according to
colour temperature required (9300K or
7400K). See tables below.
P and Q adjusted for correct reading on colour
analyser in Norm mode. For Warm and Cool
modes use offsets in table but do not adjust for
exact colour temperatures.
P and Q adjusted for correct reading on colour
analyser in Norm mode. For Warm and Cool
modes use offsets in table but do not adjust for
exact colour temperatures.
4. PinP ADJUSTMENT
1) Receive grey scale pattern (more than 8
steps).
2) Connect oscilloscope to CRT green cathode.
3) Turn on PinP using handset and move to
bright side of screen.
4) Adjust PinP contrast as follows. Contrast
values stores in E2 and will, indirectly, adjust
PinP contrast. PC software may become
available later.
Specifications / Safety Parts / Menu Trees / Service Mode / Service Mode Cont’d / Text Diagram / Voltage Tables / Voltage Tables Cont’d / 16:9 Deflection PCB
PIN VOLTAGE
14.7V SCL in
24.7V SCL out (set out of standby 0V set in standby)
34.6V SDA out (set out of standby 0V set in standby)
44.6V SDA in
54.8V Switch control supplied from +8V rail
60V Customer mode (5.0V service mode)
70V GND
84.6V SDA in
90V Customer mode (4.6V SDA out to Scart 1 service mode)
100V Customer mode (4.7V SCL out to Scart 1 service mode)
114.7VSCLin
120V Customer mode (5.0V service mode)
134.8V Switch control supplied from +8V rail
147.4V Set out of standby (4.7V set in standby)
Specifications / Safety Parts / Menu Trees / Service Mode / Service Mode Cont’d / Text Diagram / Voltage Tables / Voltage Tables Cont’d / 16:9 Deflection PCB
Specifications / Safety Parts / Menu Trees / Service Mode / Service Mode Cont’d / Text Diagram / Voltage Tables / Voltage Tables Cont’d / 16:9 Deflection PCB
Signal Processing (C2576/77TN - 311, CP2576TAN-301/351, CP2576TAN-331/381) / Signal Processing Diagram (CL2576, CP2576, CL2976, CP2976, C2976TA, C2975TAN, C2976TN)
Page 5
5HITACHI C2576 TN
16:9 Deflection PCB
Diagram
Compression Circuit Diagram
Specifications / Safety Parts / Menu Trees / Service Mode / Service Mode Cont’d / Text Diagram / Voltage Tables / Voltage Tables Cont’d / 16:9 Deflection PCB
Signal Processing (C2576/77TN - 311, CP2576TAN-301/351, CP2576TAN-331/381) / Signal Processing Diagram (CL2576, CP2576, CL2976, CP2976, C2976TA, C2975TAN, C2976TN)
Page 6
HITACHI C2576 TN
6
RGB Processing Diagram
Specifications / Safety Parts / Menu Trees / Service Mode / Service Mode Cont’d / Text Diagram / Voltage Tables / Voltage Tables Cont’d / 16:9 Deflection PCB
Signal Processing (C2576/77TN - 311, CP2576TAN-301/351, CP2576TAN-331/381) / Signal Processing Diagram (CL2576, CP2576, CL2976, CP2976, C2976TA, C2975TAN, C2976TN)
Page 7
7HITACHI C2576 TN
Dolby Audio Diagram 1
Specifications / Safety Parts / Menu Trees / Service Mode / Service Mode Cont’d / Text Diagram / Voltage Tables / Voltage Tables Cont’d / 16:9 Deflection PCB
Signal Processing (C2576/77TN - 311, CP2576TAN-301/351, CP2576TAN-331/381) / Signal Processing Diagram (CL2576, CP2576, CL2976, CP2976, C2976TA, C2975TAN, C2976TN)
Page 8
HITACHI C2576 TN
8
Dolby Audio Diagram 2
Specifications / Safety Parts / Menu Trees / Service Mode / Service Mode Cont’d / Text Diagram / Voltage Tables / Voltage Tables Cont’d / 16:9 Deflection PCB
Signal Processing (C2576/77TN - 311, CP2576TAN-301/351, CP2576TAN-331/381) / Signal Processing Diagram (CL2576, CP2576, CL2976, CP2976, C2976TA, C2975TAN, C2976TN)
Page 9
9HITACHI C2576 TN
PIP Circuit Diagram 1
Specifications / Safety Parts / Menu Trees / Service Mode / Service Mode Cont’d / Text Diagram / Voltage Tables / Voltage Tables Cont’d / 16:9 Deflection PCB
Signal Processing (C2576/77TN - 311, CP2576TAN-301/351, CP2576TAN-331/381) / Signal Processing Diagram (CL2576, CP2576, CL2976, CP2976, C2976TA, C2975TAN, C2976TN)
Page 10
HITACHI C2576 TN
10
PIP Circuit Diagram 2
Specifications / Safety Parts / Menu Trees / Service Mode / Service Mode Cont’d / Text Diagram / Voltage Tables / Voltage Tables Cont’d / 16:9 Deflection PCB
Signal Processing (C2576/77TN - 311, CP2576TAN-301/351, CP2576TAN-331/381) / Signal Processing Diagram (CL2576, CP2576, CL2976, CP2976, C2976TA, C2975TAN, C2976TN)
Page 11
11HITACHI C2576 TN
Power & Deflection Diagram 1
Specifications / Safety Parts / Menu Trees / Service Mode / Service Mode Cont’d / Text Diagram / Voltage Tables / Voltage Tables Cont’d / 16:9 Deflection PCB
Signal Processing (C2576/77TN - 311, CP2576TAN-301/351, CP2576TAN-331/381) / Signal Processing Diagram (CL2576, CP2576, CL2976, CP2976, C2976TA, C2975TAN, C2976TN)
Page 12
HITACHI C2576 TN
12
Power & Deflection Diagram 2 (C28300)
Specifications / Safety Parts / Menu Trees / Service Mode / Service Mode Cont’d / Text Diagram / Voltage Tables / Voltage Tables Cont’d / 16:9 Deflection PCB
Specifications / Safety Parts / Menu Trees / Service Mode / Service Mode Cont’d / Text Diagram / Voltage Tables / Voltage Tables Cont’d / 16:9 Deflection PCB
Specifications / Safety Parts / Menu Trees / Service Mode / Service Mode Cont’d / Text Diagram / Voltage Tables / Voltage Tables Cont’d / 16:9 Deflection PCB
Signal Processing (C2576/77TN - 311, CP2576TAN-301/351, CP2576TAN-331/381) / Signal Processing Diagram (CL2576, CP2576, CL2976, CP2976, C2976TA, C2975TAN, C2976TN)
Page 15
15HITACHI C2576 TN
Signal Processing Diagram
(C28300)
Specifications / Safety Parts / Menu Trees / Service Mode / Service Mode Cont’d / Text Diagram / Voltage Tables / Voltage Tables Cont’d / 16:9 Deflection PCB