Sharp 21HM10F Schematic
21HM-10F
SERVICE MANUAL
SEJB21HM10F00
Issued: 31st October 2001
GA-1E CHASSIS
SECAM B/G, L/L’ - PAL B/G SYSTEM COLOUR TELEVISION
MODEL 21HM-10F
In the interests of user safety (required by safety
regulations in some countries) the set should restored
to its original condition and only parts identical to
those specified should be used.
CONTENTS
ELECTRICAL SPECIFICATION.........................3
IMPORTANT SERVICING NOTES ...................4
CONTROLS & TERMINALS..............................5
SERVICE ADJUSTMENTS................................6
CHASSIS LA YOUT ...........................................12
LED FLASHING CODE....................................13
PRINTED WIRING BOARDS...........................14
ICs ADITIONAL INFORMATION......................19
SCHEMATIC DIAGRAM, WAVE FORMS........25
BLOCK DIAGRAM...........................................32
TROUBLESHOOTING T ABLES......................35
P ARTS LISTING.............................................38
SHARP CORPORATION
1
This document has been published to
be used for after sales service only.
ELECTRICAL SPECIFICA TIONS
21HM-10F
•Power Input .......................220V-240 Volts AC 50Hz
•Power Consumption
Normal Operation....................................43W
Stand-by Operation...................................3W
•Audio Power Output Rating .....................4W (MPO)
Speaker................................16
Convergence.........................Self Converging System
Focus....................................Bi-Potencial Electrostatic
Sweep Deflection...........................................Magnetic
•Picture Intermediate Frecuency.....
•White Level
Ω 4W, 9 x 5 cm, 1pc
.........38.9MHz
•Sound Carrier Trap
L’..........................................................40.4MHz
L...........................................................32.4MHz
B/G.......................................................33.4MHz
•Adjacent Sound Carrier Trap
L’..........................................................32.4MHz
L, B/G...................................................40.4MHz
•Adjacent Picture Carrier Trap
L’..........................................................41.9MHz
L...........................................................30.9MHz
B/G.......................................................30.9MHz
•Aerial Input Impedance
VHF/UHF...........................75 ohm Unbalanced
•Tuning Ranges
L/L’..........................55.75MHz thru 855.25 MHz
B/G.........................48.25MHz thru 855.25 MHz
CATV Special Channels
Set the brightness control, with no signal connected, so that the CRT cathode current is 600mA. The maximum
correction applied to each cathode current to achieve a screen temperature of 8900 degrees K-20 MPCD should
not exceed 15% of its original value.
X Y Screen temperature
0.290 ± 0.015 0.284 ± 0.015 8900º K-20 MPCD
Specifications are subject to change without prior notice.
WARNING
The chassis in this receiver is partially hot. Use an isolation transformer between the line cord plug
and power receptacle, when servicing this chassis.
To prevent electric shock, do not remove cover. No user-serviceable parts inside. Refer servicing to
qualified service personnel.
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21HM-10F
IMPORTANT SERVICING NOTES
Only qualified service personnel are allowed to carry out maintenance and repair of this receiver.
SERVICING OF HIGH VOLTAGE SYSTEM AND CRT
It is important that the static charge is removed from the high voltage system when carrying out work
on the receiver. This can be achieved by connecting a 10K resistor (with a suitably insulated lead) from
the CRT cavity connector to the CRT ground tag. This must be carried out with the AC supply disconnected from the receiver.
Note the following:
• The CRT in this receiver employs Integral Implosion Protection.
• If the CRT has to be changed it MUST be replaced with the correct type for continued safe
working
• DO NOT lift the CRT by its neck.
• When handing the CRT , ensure that shatterproof goggles are worn.
• Ensure that the CRT is discharge before handling.
X-RAY
This receiver is designed to keep any x-ray emission to an absolute minimum. Some fault conditions
and servicing procedures may produce potentially hazardous x-ray radiation levels. This is a problem
when in close proximity to the receiver for long periods of time. To reduce any risks associated with
this, please observe the following precautions:
1. When undertaking any servicing on this chassis, DO NOT increase the EHT to more than 30.5 KV,
(at a instantaneous beam current of 1300µΑ).
2. Ensure that during normal operation the EHT does not exceed 25.0 KV
1100µΑ). This level has been preset in the factory. Always check that this level has not been ex-
ceeded after carrying out any repair on the receiver.
3. DO NOT replace the CRT with any other type than that specified in the parts listing as this may
cause excessive x-ray radiation.
±1.5KV (at a beam current of
BEFORE RETURNING THE RECEIVER TO THE CUSTOMER
In addition to the above checks, the following should also be carried out before returning the receiver
to the customer.
1. Inspect all the leads to ensure that they are dressed correctly and that they are not obstructed or
pinched by any other parts.
2. Ensure that all protective devices are in good condition. These will include nonmetallic control
knobs, insulating fish papers, cabinets backs, compartment covers or shields, mechanical insulators,
etc.
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Location of Controls
21HM-10F
Remote Control
POWER/STANDBY ( ) button
Programme Select buttons
FLASHBACK ( ) buttons
Returns to previously viewed
programme
VOLUME UP ( )/DOWN ( ) buttons
( ) Increases sound
( ) Decreases sound
(These are also used for menu set up)
SOUND MUTE ( ) button
CALL button ( )
TV/VIDEO
1 2 3
4 5 6
7 8 9
0
CH
CH
TV
Infrared Transmitter Window
Aim this window at the infrared sensor
on your TV set
TV/VIDEO Select button
Single/Double Entry button ( )
CHANNEL (PROGRAMME) UP ( )/
DOWN ( ) buttons
( ) Selects next higher programme
( ) Selects next lower programme
(These are also used for menu
MENU
CHILD LOCK ( ) button
set up)
MENU button
TV Front
MENU CH
Power ( ) button
Power/On Timer indicator
Remote Control Sensor
Menu button
Volume Up ( )/Down ( ) buttons
Euro-SCART 21-Pin Terminal
For greater A/V enjoyment, various audio and video devices may be
connected via the Euro-SCART 21-Pin Terminal.
1. Audio right output
2. Audio right input
3. Audio left output
4. Common earth for audio
5. Earth for blue
6. Audio left input
7. Blue input
8. Audio-video control
9. Earth for green
10. Not used
11. Green input
12. Not used
13. Earth for red
14. Not used
15. Red input
16. Red/Green/Blue
17. Earth for video
Audio: Mono Input/Output.
Channel Up ( )/Down ( ) buttons
21-Pin Euro-
18. Earth for video
19. VIDEO output
control
20. VIDEO input
21. Common earth
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21HM-10F
SERVICE ADJUSTMENT
• SERVICE MODE FUNCTION
All required adjustments for servicing this TV set, may be done in “service mode”, excepting G2 and FOCUS.
HOW TO ACCESS THE SERVICE MODE
1. Turn the receiver on and ensure that it is tuned into a test pattern.
MENU
CH
2. Turn the receiver off using the mains switch.
3. Press the volume down and channel up buttons together. See Fig.1.
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4
4. Continue pressing the volume down and channel up buttons while turning
the mains on using the mains switch. See Fig.1.
Fig.1
5. Keep pressing the volume down and channel up buttons until the picture appears.
6. When <<SHARPX X VXX.XX>> appears on the screen, release the two buttons.
7. The receiver is now in the service mode. See Fig. 2.
To move between the various service mode functions, use the channel up and down buttons. See Fig. 3.
Use the volume buttons to change the data to the desired value. See Fig. 3.
The data will be stored automatically when exiting the service mode. To exit the service mode press the standby button
on the remote control or turn the receiver off with the mains switch.
Fig. 2
SHARP X X VXX.XX
STS0: XXXX XXXX
STS1: XXXX XXXX
STS2: XXXX XXXX
Adjustment
(Yellow)
Fig. 3
XXXX:
XX:
Value
(Green)
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21HM-10F
• SERVICE ADJUSTMENTS AND DATA LIST
The table below shows the various service mode positions, range of values and default value. The columns are headed
as follows.
Heading: Description:
OSD This is what will appear on the screen when at this position
Function This is the description of the mode’s function
Range This is the range of values that can be entered while in this mode
Initial This is the initial value, i.e. just after changing the NVM
Default This is the recommended default value for this mode
FIX/ADJ If this is ADJ, then it may be necessary to adjust this value away from the default
No. OSD Function Range Initial Default FIX/ADJ
1 AGC AGC Take Over Point 0...63 14 14 ADJ
2 V-LIN Vertical Slope [VS] 0...63 32 32 ADJ
3 V-AMP V ertical Amplitude [VA] 0...63 32 32 ADJ
4 V-CENT Vertical Shift [VSH] 0...63 32 32 ADJ
5 H-CENT Horizontal shift [HS] 0...63 32 32 ADJ
6 H-CENT60 offset to H-CENT for60 Hz 0...31 data(-16..+15) 16 20 FIX
7 EW / / Horizontal Parallelogram [HP] 0...63 32 32 FIX
8 HB Horizontal Bow 0...63 32 32 FIX
9 S-COR S-Correction [SC] 0...63 0 22 FIX
10 DRI-RS White point Red Standard white temp. 0...63 32 42 ADJ
11 DRI-GS White point Green Standard white temp. 0...63 32 42 ADJ
12 DRI-BS White point Blue Standard white temp 0...63 32 42 ADJ
13 DRI-RW White point Red Warm white temp. 0...32 16 16 FIX
14 DRI-GW White point Green Warm white temp. 0...32 16 9 FIX
15 DRI-BW White point Blue Warm white temp. 0...32 16 9 FIX
16 DRI-RC White point Red Cold white temp. 0...32 16 9 FIX
17 DRI-GC White point Green Cold white temp. 0...32 16 9 FIX
18 DRI-BC White point Blue Cold white temp. 0...32 16 16 FIX
19 SUB-VOL Max Volume 0...63 60 60 FIX
20 SUB-CON Sub Contrast 0...63 63 63 FIX
21 SUB-COL Sub Colour 0...63 32 18 FIX
22 SUB-BRI Sub Brightness 0...63 32 36 FI X
23 TIN T Sub Tint 0...63 32 32 FI X
24 SUB-SHP Sub Sharpness 0...63 32 18 FIX
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21HM-10F
No. OSD Function Range Initial Default FIX/ADJ
25 HTL-VOL Max Hotel Volume 0...63 30 30 FIX
26 HTL-PRG Hotel Program number 0...99 or > 99 for none 255 255 FIX
27 RGB OSD RGB Reference 0...15 1 5 0 FIX
28 SEARCH-SYS Sound system for auto turning 0(L-BG),1(BG),2(I),3(DK) 1 0 FIX
29 CUT-R Black Level off-set R [BLR] 0...63 0 0 FIX
30 CUT-G Black Level off-set G [BLB] 0...63 0 10 FIX
31 CDL Cathode Drive Level [CL] 0...15 0 5 FIX
32 DL-PT Y-Delay time for PAL (TV) [YD] 0...15 12 4 FIX
33 DL-ST Y-Delay time for SECAM (TV) [YD] 0...15 1 5 8 FIX
34 DL-4T Y-Delay time for N443 (TV) [YD] 0...15 12 8 FIX
35 COL-OP COLOUR OFFSET (PAL) 0...15 8 8 FIX
36 COL-OS COLOUR OFFSET (SECAM) 0...15 8 8 FIX
37 COL-O4 COLOUR OFFSET (NTSC443) 0...15 4 4 FIX
38 SHP-OP SHARPNESS OFFSET(PAL) 0...15 8 8 FIX
39 SHP-OS SHARPNESS OFFSET(SECAM) 0...15 4 4 FIX
40 SHP-O4 SHARPNESS OFFSET(NTSC443) 0...15 8 8 FIX
41 SC-VOL SCART volume 0..255 11 5 115 FIX
42 PRE-SC Prescaler SCART input 0..127 2 5 25 FIX
43 PRE-FM Prescaler FM/AM 0..127 7 2 72 FIX
44 PRE-NICAM Prescaler SCART input 0..127 0 0 FIX
45 AVC-DKY AVC Decay 0...3 data(1.2.4.8.) 2 2 FIX
46 AC-OFF-TIM Time to set the AC-OFF 0..15 0 0 FIX
timer is in steps of 10minutes
47 DISP Language or symbols 0(symboles), 0 2 FIX
1(English),
2(French)
48 TXT-EUR Teletext pan-European language 0 (teletext pan-european language) 0 0 FIX
1 (second language;cyrillic)
2(third language;Greek)
49 BKS Black Stretch 0 (disable) or 1 (enable) 1 1 FIX
50 AVC Automatic Volume Control(AVL) 0 (disable) or 1 (enable) 0 1 FIX
51 FFI Fast Filter IF-PLL 0 (disable) or 1 (enable) 0 0 FIX
52 ACL Auto Colour Limit 0 (disable) or 1 (enable) 0 1 FIX
53 S-L Sound system L 0 (disable) or 1 (enable) 0 1 FIX
54 S-DK Sound system DK 0 (disable) or 1 (enable) 1 0 FIX
55 S-I Sound system I 0 (disable) or 1 (enable) 1 0 FIX
56 S-BG Sound system BG 0 (disable) or 1 (enable) 1 1 FIX
57 BLUE-BACK Video mute at Ident loss 0 (disable) or 1 (enable) 1 1 FIX
58 VMC Video Mute at program/source Change 0 (disable) or 1 (enable) 1 1 FIX
59 HTL Hotel mode 0 (disable) or 1 (enable) 0 0 FIX
60 BTSC Reduced FM demodulator Gain (for BTSC sig) 0 (disable) or 1 (enable) 0 0 FIX
61 AV Number of external AV sources 0 for 1 AV or 1 for 2 AV 1 0 FIX
62 FMWS FM Window Selection 0 (disable) or 1 (enable) 0 0 FIX
63 SM0 Sound Mute bit 0 0 (disable) or 1 (enable) 1 1 FIX
64 SM1 Sound Mute bit 1 0 (disable) or 1 (enable) 0 0 FIX
65 AGC0 IF AGC speed bit0 0 (disable) or 1 (enable) 1 0 FIX
66 AGC1 IF AGC speed bit1 0 (disable) or 1 (enable) 0 0 FIX
67 FOA-FE Phi 1 time constant for FE(RF) 0 (disable) or 1 (enable) 0 0 FIX
68 FOB-FE Phi 2 time constant for FE(RF) 0 (disable) or 1 (enable) 0 0 FIX
69 FOA-AV Phi 1 time constant for A V 0 (disable) or 1 (enable) 1 1 FIX
70 FOB-AV Phi 2 time constant for A V 0 (disable) or 1 (enable) 1 1 FIX
71 TXT Teletext 0 (disable) or 1 (enable) 0 0 FIX
72 TXT-WE Teletext Western or Eastern characters 0 (westem) or 1 (eastem) 0 0 FIX
73 FSL Forced V-SYNC slicing level 0 (disable) or 1 (enable) 0 0 FIX
74 HP2 Sync of OSD 0 for Ph1 or 1 for Ph2 0 0 FIX
75 CP Charge pump 0 (fast tuning) or 0 0 FIX
1 (moderate speed tuning)
76 NICAM NICAM decoding enabled 0 (disable) or 1 (enable) 0 0 FIX
77 IGR IGR decoding enabled 0 (disable) or 1 (enable) 0 0 FIX
78 AUTO Start auto tuning at POWER-ON 0 (disable) or 1 (enable) 0 0 FIX
79 TXT-TGL Function of TXT key 0 or 1 0 1 FIX
80 EVG Enable Vertical Guard 0 (disable) or 1 (enable) 1 1 FIX
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• SCREEN ADJUSTMENT
1. G2 Adjustment
1. Enter the service mode (see page 6).
2. Use the channel up or channel down buttons to enter the << BLUE-BACK >>
function.
3. Set this to << BLUE-BACK: 0 >>, i.e. blue background is turned of f.
4. Turn the set off at the mains.
5. Turn the set back on.
6. Set the picture control settings to normal.
7. Select the SCART input by pressing the TV/SCAR T button on the remote control. Do not connect an input to the SCART socket. A blank raster will appear.
21HM-10F
9GF
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8. Connect an oscilloscope to TP851 on the CR T PWB. The waveform as in figure 4 should be displayed.
9. Adjust the G2 control (screen voltage) so that the peak of this waveform is 3.0V
+/-0.1V above the zero volt line.
10. Enter the service mode.
11. Turn the blue background function back on again - set << BLUE-BACK: 1 >>.
12. Turn off the receiver using the mains button.
13. The G2 adjustment is now complete.
2. Focus Adjustment
1. Receive a monoscope pattern signal at a level of 60 to 80 dBµV.
2. Set the picture settings to normal.
3. Adjust the focus potentiometer to obtain maximum definition.
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Fig. 4
• AGC ADJUSTMENT
1. Tune the receiver into a colour bar signal on channel E-12.
2. Set the RF generator to an output signal strength of 57dBµV (+/-1dBµV) –50 Ohms unbalanced.
3. Connect an oscilloscope to TP201. TP201 is one end of R201.
4. Enter the service mode (see page 6).
5. Use the channel up and channel down buttons to enter the AGC mode.
6. By using the volume up and the volume down buttons, adjust the AGC until the voltage on TP201 drops by 0.1V
to 0.3V below its maximum value.
7. Change the input signal strength to 66-70dBµV and make sure that there is no noise apparent in the picture.
8. Turn the receiver off at the mains, this will exit the service mode and store the adjustment.
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21HM-10F
• GEOMETRY ADJUSTMENT PROCEDURE
To adjust the geometry , follow the procedure outlined below:
1.Tune the set into a Philips test pattern.
2.Enter the service mode as described on page 6.
3.Use the channel up or channel down buttons to enter the desired mode
4.Use the volume buttons to achieve correct setting.
5.When adjustments are complete, use the standby button to turn off the set. The adjustment values will be stored
at this point.
V-LIN
Adjust the vertical linearity control so that the picture centring is as shown in figure 5.
V-AMP
Adjust the vertical amplitude control so that the picture overscans as shown in figure 6.
V-CENT
Adjust the vertical centring control so that the picture is centred as shown in figure 7.
Fig. 5
Fig. 6
H-CENT
Adjust the horizontal centring control so that the picture is centred as shown in figure 8.
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Fig. 7
Fig. 8
21HM-10F
•COLOUR ADJUSTMENT PROCEDURE
The following adjustments should only be carried out when the CRT or IC801 are replaced.
NOTES:
• This adjustment must be done after warming up the unit for 30 minutes or longer with a beam current over 700
µA.
• The red value «DRI-RS» should be fixed to 42. (Refer to “How to access service mode” section).
• «DRI-GS» adjustment alters “Y” co-ordinate.
• «DRI-BS» adjustment alters “X” and “Y” co-ordinates.
ADJUSTMENT METHOD 1 (using the signal generator, varying the picture signal)
1. Adjust G2.
2. Input a white pattern with burst signal from SCART.
3. Position the colorimeter in the centre of screen.
4. Adjusting input signal level, select a luminance of 70 nits.
5. Operate again in “service mode“ and select «DRI-GS» and/or «DRI-BS» locations to obtain colour co-ordinates:
X Y Screen temperature
0.290 ± 0.015 0.284 ± 0.015 8900º K-20 MPCD
6. Re-set the TV with the mains switch button to store the adjustment and exit service mode.
7. Check colour co-ordinates “X” and “Y” at 20 a 120 Nits. It may be necessary to repeat the same procedure to
obtain the above values.
ADJUSTMENT METHOD 2 (using the signal generator, with a fixed picture signal)
1. Adjust G2.
2. T une a white pattern with burst signal.
3. Operate in “service mode”:
4. Using «SUB-CON», select a luminance of 70 nits.
5. Operate again in “service mode“ and select «DRI-GS» and/or «DRI-BS» locations to obtain colour co-ordinates:
X Y Screen temperature
0.290 ± 0.015 0.284 ± 0.015 8900º K-20 MPCD
6. Select «SUB-CON». Return data to “63”.
7. Re-set the TV with the mains switch button to store the adjustment and exit service mode.
8. Check colour co-ordinates “X” and “Y” at 20 a 120 Nits. It may be necessary to repeat the same procedure to
obtain the above values.
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