Sharp 37 DM 23H Schematic
SHARP 37DM-23H
General Information
Also Covers
37EM-33H
CA-1 Chassis
Recommended Safety Parts
Item Part No. Description
VB34EAC0136*N S CRT Ass’y, 34 cm(14”) CD
QEARC0002BMZZ S Wire, Grounding strap
TU201 RTUNH0125BMZZ S Tuner AY
IC701 RH-FX0103BMZZ S Photo Coupler AD
L701 RCiLF0157BMZZ S Coil AL
T601 RTRNF2047BMZZ S H-Volt Transformer AY
T700 RTRNZ0535BMZZ S Transformer AR
C702 RC-FZ0070BMZZ S 0.1 250V Mylar AD
C722 RC-KZ0106GEZZ J 3300p 4kV Ceramic AG
R240 RR-XZ0100BMZZ S 11/3W Fuse Resistor AB
R305 RR-XZ0204BMZZ S 2.2 1/3W Fuse Resistor AB
R504 RR-XZ0109BMZZ S 5.6 1/3W Fuse Resistor AB
R506 RR-XZ0100BMZZ S 11/3W Fuse Resistor AB
R512 RR-XZ0109BMZZ S 5.6 1/3W Fuse Resistor AB
R603 RR-XZ0200BMZZ S 11/2W Fuse Resistor AB
R611 RR-XZ0242BMZZ S 3.3k 1/2W Fuse Resistor AB
R721 VRC-UA2HG825K R 8.2M 1/2W Solid AA
R722 VRC-UA2HG825K R 8.2M 1/2W Solid AA
P701 QPLGN0304CEZZ R Plug AB
P702 QPLGN0207CEZZ R Plug AA
F701 QFS-C3226CEZZ R Fuse T3.15A AE
S701 QSW-P0588CEZZ R Power AP
SC881 QSOCV0842CEZZ R Socket AH
RCILG0415BMZZ S Degaussing Coil AM
with Deflection Yoke,
Purity Magnet and Wedges
Safety Notes
IMPORTANT SERVICE NOTES
Maintenance and repair of this receiver should
be carried out by qualified service personnel
only.
SERVICING OF HIGH VOLTAGE SYSTEM
AND PICTURE TUBE
When servicing the high voltage system, remove
static charge from it by connecting a 10 k ohm
resistor in series with an insulated wire (such as
a test probe) between picture tube ground tag
and high voltage lead (AC line cord should be
disconnected from AC outlet).
1.Picture tube in this receiver employs integral
implosion protection.
2.Replace with tube of the same type number
for continued safety.
3.Do not lift picture tube by the neck.
4.Handle the picture tube only when wearing
shatterproof goggles and after discharging the
high voltage completely.
X-RAY
This receiver is designed so that any X-Ray
radiation is kept to an absolute minimum. Since
certain malfunctions or servicing may produce
potentially hazardous radiation with prolonged
exposure at close range, the following precautions should be observed.
1.When repairing the circuit, be sure not to
increase the high voltage to more than 30.0
kV (1100uA Beam currrent) for the set.
2.To keep the set operating normally, be sure to
maintain the high voltage at 24.5kV Plus
Minus 1.5kV (at a beam current of 1100uA).
The set has been factory adjusted to the
above mentioned high voltage. If there is a
possibility that the high voltage fluctuates as
result of the repairs, never forget to check for
such high voltage after the work.
3. Do not substitute a picture tube with unauthorized types or brands which may cause
excess X-Ray radiation.
BEFORE RETURNING THE RECEIVER
In addition to the checks necessary as a result
of a repair having been carried out, the following
additional safety checks should also be made
before returning the unit to the user.
1.Inspect all lead insulation to make certain that
leads are not pinched or that hardware is not
lodged between the chassis and other metal
parts in the receiver.
2.Inspect all protective devices such as nonmetallic control knobs, insulating fishpapers,
cabinet backs, adjustment and compartment
covers or shields: isolation resistor-capacity
networks, mechanical insulators, etc.
3.Apply test voltage of 3000 volts between live
parts and accessible metal parts for 3
seconds.
SERVICE MODE FUNCTION
This mode function is provided to assist with the
settings of those adjustments that may vary
from one Picture Tube to another, or between
models.
In order to use the Service Mode
1. Press main switch to OFF.
2. Connect Test Pattern signal to antenna
terminal.
3. Press DOWN and CH UP buttons and main
switch to ON simultaneously.
4. —SERV—will appear on screen. Service
mode is now entered.
5. Select adjustment using buttons UP CH DOWN.
To exit service mode, press main switch to
OFF or press MENU button on R/C.
6. For “a” thru j selections.
Adjustment to a selection can be made by
pressing buttons UP * DOWN ).
A colour bar is displayed on the OSD to indicate
the adjustment position, together with hexadecimal numbers (Not for GII adjustment).
For “k” Selection.
NVM storage location settings variants.
In order to have access to the desired storage
location, buttons UP * DOWN should be
pressed, as required, to obtain a higher or lower
location, respectively. Bear in mind that, for
storage location indication a hexadecimal
numerical system is used, instead of a decimal
system.
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F, 10, 11
..........19, 1A, 1B, 1C, 1D, 1E, 1F, 20, 21, 99,
9A, 9B, 9C, 9D, 9E, 9F, A0, A1, ...........,
B0..........., C0..........., D0..........., E0..........., F0,
F1, F2, F3, F4, F5, F6, F7, F8, F9, FA, FB, FC,
FD, FE, FF.
From the last location FF to the first 00 can be
reached by increasing and from first to last by
decreasing. Once the storage location to be
varied has been selected, its value can be
modified by the bits that form part of the storage
location numerical buttons, numbers 0 to 7,
respectively. This switches its binary number
from and between 0 and 1 each time one of the
buttons is pressed.
0=20 1, 1 W=21=2, 2=22 4, .....
(See Tables on next page).
• PIF/AGC Adjustment
1. VCO + AFT Adjustment
1.Connect the output of SSG (Standard Signal
Generator) to the tuner IF output terminal.
• SSG output: 38.9 MHz (CW) ±5 kHz).
• SSG output level: approx. 90 dBuV.
2. Enter into Service Mode.
3. Push CH UP until AFT appears.
4. Press button on R/C. Setting is made
automatically. During this setting the colour
bar shall go from red to yellow. When setting
is finished, colour bar disappears and BSTOP (bus stop) is shown on screen.
5. Switch set OFF and ON again, setting is now
memorized.
2. RF-AGC Out-In Adjustment (12C BUS)
1. Receive the “COLOUR BAR” signal (Channel
E-12).
• Signal strength: 60 dBuV.
2. Enter into Service Mode.
3. Push CH UP until AGC appears.
4. Press button on R/C. Setting is made
automatically. During this setting the colour
bar shall go from red to yellow. When setting
is finished, colour bar disappears and BSTOP (bus stop) is shown on screen.
5. Switch set OFF and ON again, setting is now
memorized.
• Screen Adjustment
3. Focus Adjustment
1. Apply mains voltage of 220 V AC/50 Hz to TV.
2. Receive Phillips pattern signal to a level
between 60 and 80 dBuV.
3. Set contrast to 10/10, brightness to 5/10 and
colour 0/10.
4. Adjust focus potentiometer to obtain maximum definition.
4. G2 Adjustment
1. Apply mains voltage of 220 V AC/50 Hz to TV.
2. Receive MONOSCOPE PATTERN signal to a
level between 60 and 80 dBuV.
3. Apply 10 K* to the anode of D1012 and DC
5V to it through the diode.
4. Press the TEXT key of R/C and set to level.
5. Set to the point where the raster disappears
on the screen VR of FBT.
• GEOMETRY ADJUSTMENT PROCEDURE
1. H-SHFT
a) Receive Philips pattern signal.
b) When * UP button is pressed, picture moves
to the left.
c) When * DOWN button is pressed, picture
moves to the right.
d) Adjust the horizontal location to obtain picture
centering (fig. 1)
2. V-SHFT
a) Receive Philips pattern signal.
b) When * UP button is pressed, picture moves
up.
c) When * DOWN button is pressed, picture
moves down.
d) Adjust the horizontal location to obtain picture
centering (fig. 2)
3. V-AMPL
a) Receive Philips pattern signal.
b) When * UP button is pressed, vertical size of
picture increases.
c) When * DOWN button is pressed, vertical size
of picture decreases.
d) Adjust the vertical size to obtain overscan (fig.
3).
4. V-SLOP
a) Receive Philips pattern signal.
b) When .* UP button is pressed, upper picture
scanning decreases and lower picture
scanning increases.
c) When * DOWN button is pressed, upper
picture scanning increases and lower picture
scanning decreases.
d) Adjust the vertical symmetry to obtain
symmetrical scanning between upper and
lower picture (fig. 4).
COLOUR ADJUSTMENT
5. V-DLY
a) Receive Philips pattern signal.
b) When * UP button is pressed, luma phase
delays.
c) When * DOWN button is pressed, chroma
phase delays.
d) Adjust the chroma-luma delay.
The following adjustments are only required
when the Picture Tube is changed.
6. “GAIN R”, “GAIN G”, “GAIN B”.
a) Adjust G2.
b) Tune in white card.
c) Adjust colour to minimum.
d) Position colourmeter in the center of screen.
e) Using brightness and contrast buttons, select
a luminance of 120 nits.
f) Operate again in Service Mode and select
location GAIN R, GAIN B to obtain colour
coordinates:
X= 0.290 ± 0.015
Y= 0.284 ± 0.015
g) Exit Service Mode and check colour coordinates ‘X’ and ‘Y’ at 20 and 120 NITS. It may be
necessary to repeat procedure
NOTE:
Locations: GAIN R alter ‘X’ coordinate; GAIN G
alter the ‘Y’ coordinates; GAIN B alter the ‘X’
and ‘Y’coordinates.
CHILD LOCK CANCEL
The following process describes how to cancel
actual password (PIN) when the customer
forgets code.
1. Switch ON TV set.
2. Press button DOWN * on TV and 0n on R/C
simultaneously.
3. Press MENU button on R/C to input menu.
4. Using buttons UP CH DOWN move to *
position.
5. Press MENU button again.
6. Select PIN and input new PIN (Please do not
forget it)
7. Select EXIT and press MENU button again.
Fig. 1
Fig. 2
Fig. 3
Fig. 4
SHARP 37DM-23H
Service Adjustments Cont’d
Remote Control Diagram
Waveforms
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