Samsung CMB5477L Reference manual

Disclaimer: This information is provided “as is” without warranty of any kind
either expressed or implied, including, but not limited to, the implied
warranties of merchantability and fitness for a particular purpose.
REV 10-1
SUBJECT: CRT Substitution
BACKGROUND: Samsung is manufacturing the CMB5477L with three different
manufacturer’s CRTs. Each type of CRT has parts that differ in
the heater, brightness, and the deflection circuits.
SOLUTION: The parts that differ from each other are listed in the parts list
below.
PARTS LIST: See the back of this cover page.
SERVICE BULLETIN
PRODUCT: Computer Monitor
BULLETIN: Monitor 95-004
MODEL: CMB5477L

Disclaimer: This information is provided “as is” without warranty of any kind
either expressed or implied, including, but not limited to, the implied
warranties of merchantability and fitness for a particular purpose.
REV 10-1
Location No. Phillips CRT Toshiba CRT SDD CRT
CRT TYPE : M36EDR320X TYPE : M36KUT23XX01 TYPE : M36KUK35X02
(CODE : 897-250089AA) (CODE : 897-250192AA) (CODE : 897-250134AA)
R209 R-CAR, 10K, 1/6W R-CAR, 15K, 1/6W R-CAR, 15K, 1/6W
(CODE : 911-151007YA) (CODE : 911-151507AA) (CODE : 911-151507AA)
R463 R-CAR, 15K, 1/6W R-CAR, 10K, 1/6W R-CAR, 15K, 1/6W
(CODE : 911-151507AA) (CODE : 911-151007YA) (CODE : 911-151507AA)
R461 R-M, OXIDE, 1.5, 3W R-M, OXIDE, 1.2, 3W R-M, OXIDE, 1.2, 3W
(CODE : 911-311507LFXA) (CODE : 911-311207JF) (CODE : 911-311207JF)
R184 R-CAR, 100K, 1/6W R-CAR, 75K, 1/6W R-CAR, 100K, 1/6W
(CODE : 911-161007YA) (CODE : 911-157507YA) (CODE : 911-161007YA)
JP25 JUMPER WIRE R-CAR, 27K, 1/6W JUMPER WIRE
(CODE : 911-152707YA
L403 COIL-CHOKE, 57UH COIL-CHOKE, 100UH COIL-CHOKE, 100UH
(CODE : 925-460191FA) (CODE : 925-460192BA) (CODE : 925-460192BA)
R630 R-M, OXIDE, 2.7, 3W R-M, OXIDE, 2.7, 3W R-M, OXIDE, 1.5, 3W
(CODE : 911-312707LF) (CODE : 911-312707LF) (CODE : 911-311507LFXA)
R631 R-M, OXIDE, 3.9, 3W R-M, OXIDE, 3.9, 3W R-M, OXIDE, 1.5, 3W
(CODE : 911-313907LF) (CODE : 911-313907LF) (CODE : 911-311507LFXA)
R307 R-CAR, 470, 1/2W R-CAR, 470, 1/2W R-CAR, 330, 1/2W
(CODE : 911-134707FF) (CODE : 911-134707FF) (CODE : 911-133307FF)
C461 C-M, P.P, 1.6KV, 552-J C-M, P.P, 1.6KV, 552-J C-M, P.P, 1.6KV, 502-J
(CODE : 916-944550YJAX) (CODE : 916-944550YJAX) (CODE : 916-354560YJAX)
R472 R-M, OXIDE, 180, 2W R-M, OXIDE, 180, 2W R-M, OXIDE, 75, 2W
(CODE : 911-331807JF) (CODE : 911-331807JF) (CODE : 911-331807JA)
D428 NONE NONE RGP02-12
(CODE : 02169-206-297)
R414 R-M.F, 22K, 1/4W R-M.F, 24K, 1/4W R-M.F, 24K, 1/4W
(CODE : 911-452205DA) (CODE : 911-452405DA) (CODE : 911-452405DA)
R444 R-M, OXIDE, 1.2, 2W R-M, OXIDE, 1.5, 2W R-M, OXIDE, 1.5, 2W
(CODE : 911-311207JF) (CODE : 911-311507JF) (CODE : 911-311507JF)
R422 R-M, OXIDE, 1.2, 2W R-M, OXIDE, 1.5, 2W R-M, OXIDE, 1.5, 2W
(CODE : 911-311207JF) (CODE : 911-311507JF) (CODE : 911-311507JF)
L407 H-LIN, COIL, 4.9UH H-LIN, COIL, 4.9UH H-LIN, COIL, 4.7UH
(CODE : 923-460191EA) (CODE : 923-460191EA) (CODE : BH26-30027A)
T403 H-PULSE, TRANS, 1.0MH H-PULSE, TRANS, 1.5MH H-PULSE, TRANS, 1.5MH
(CODE : 923-460169DA) (CODE : BH26-30023A) (CODE : BH26-30023A)
C419 C-POLY, 100V, 102-J C-POLY, 100V, 182-J C-POLY, 100V, 182-J
(CODE : 916-164100LJAH) (CODE : 916-164180LJAH) (CODE : 916-164180LJAH)
R207 R-CAR, 9.1K, 1/6W R-CAR, 4.7K, 1/6W R-CAR, 4.7K, 1/6W
(CODE : 911-149107YA) (CODE : 911-144107YA) (CODE : 911-144107YA)

Disclaimer: This information is provided “as is” without warranty of any kind
either expressed or implied, including, but not limited to, the implied
warranties of merchantability and fitness for a particular purpose.
REV 9-1
SUBJECT: Vertical Deflection Circuit Improvement
BACKGROUND: The Samtron 14 inch computer monitor SC-428PS has no
vertical deflection after power up due to IC301 (TDA4866) and R301 failing. The
problem is likely to occur with the serial number range of A9524002821 to
A9538025160. Serial numbers after A9538025160 use a different IC301
(TDA8351). These are not interchangable without making various circuit
changes to meet the specifications of the new IC301.
SOLUTION: The counter measure to keep the original IC301 (TDA4866) from
failing is done by improving the grounding on the monitor. Two ground lugs and
two additional ground wires have been added. See the attached page for
mounting procedures.
PARTS LIST: Below are the parts added to Serial Number Range A9524002821
to A9538025160
Location No. Part No. Description
None 3621200274 Wireform UL1015-AWG 22
200 mm BK
None 3112400051 GND Lug 54 X 18 X 30 X 0.35T
SERVICE BULLETIN
PRODUCT: Computer Monitor
BULLETIN: Monitor 95-005
MODEL: Samtron SC-428PS

Disclaimer: This information is provided “as is” without warranty of any kind
either expressed or implied, including, but not limited to, the implied
warranties of merchantability and fitness for a particular purpose.
REV 9-1
Mounting Procedure - Add a ground lug to point A and point D as in the figure
shown below. Take the 200mm wires and route them through the holes labeled
E and F in the main pcb as in the diagram below. The holes are located next to
the IC301 heatsink. Solder the 200mm wires to the heatsink solder connection
located nearest to the routed wire hole. The other end of the 200mm wires are to
be soldered to the CRT ground wire as shown below.

Disclaimer: This information is provided “as is” without warranty of any kind
either expressed or implied, including, but not limited to, the implied
warranties of merchantability and fitness for a particular purpose.
REV 11-1
SUBJECT: Vertical Circuit Modification
BACKGROUND: The vertical output IC301 has been changed from a TDA4866
to a TDA8351. The circuit change was made with serial numbers higher than
A95025160. The circuit change was made due to the failure of IC301 in some
cases during power up.
SOLUTION: The circuitry around IC301 was changed to meet the specifications
of the TDA8351.
PARTS LIST:
SN. A9524002821 TO A9538025160 SN. A9538026160 TO ?
Location No. Part No. Description Part No. Description
C306 NONE NONE 1218204707 C-CERAMIC
47PF, 50V
R310 NONE NONE 1412104229 R-CARBON
4.2K, 1/6W
R303 1413401021 R-CARBON 1413402214 R-CARBON
1K, 1/4W 220, 1/4W
R304 1414201R01 R-CARBON 1433601R0B R-CARBON
1, 1/2W 1, 1W
R307 141420R508 R-CARBON 1433601R0B R-CARBON
0.5, 1/2W 1, 1W
IC301 2332290235 IC, TDA4866 2332190339 IC, TDA8351
SERVICE BULLETIN
PRODUCT: Computer Monitor
BULLETIN: Monitor 95-006
MODEL: Samtron SC-428PS

Disclaimer: This information is provided “as is” without warranty of any kind
either expressed or implied, including, but not limited to, the implied
warranties of merchantability and fitness for a particular purpose.
REV 12-1
SUBJECT: No Raster
BACKGROUND:There is a delay in the 12V/DC operation. Due to the delay the
166V/DC line operates first when power is first applied to the monitor. This will
affect the horizontal circuit and cause a surge, which in turn will cause Q403 and
Q408 to short.
SOLUTION: Insert a IN4937 diode into location D300 and substitute R401 (33
ohm, 1/2W) with a 220 uH coil.
PARTS LIST:
Original Parts New Parts
Location Parts Code Description Parts Code Description
R401 911-123307FF R-Carbon, 33, 1/2w 925-001001AN Coil, 220 uH
D300 None None 893-314937AC Diode, IN4937
SERVICE BULLETIN
PRODUCT: COMPUTER MONITOR
BULLETIN: MONITOR 95-007
MODEL: CQB4147

Disclaimer: This information is provided “as is” without warranty of any kind
either expressed or implied, including, but not limited to, the implied
warranties of merchantability and fitness for a particular purpose.
REV 12-1
SUBJECT: No Raster
BACKGROUND:There is a delay in the 12V/DC operation. Due to the delay the
166V/DC line operates first when power is first applied to the monitor. This will
affect the horizontal circuit and cause a surge, which in turn will cause Q403 and
Q408 to short.
SOLUTION: Insert a IN4937 diode into location D300 and substitute R401 (33
ohm, 1/2W) with a 220 uH coil.
PARTS LIST:
Original Parts New Parts
Location Parts Code Description Parts Code Description
R401 911-123307FF R-Carbon, 33, 1/2w 925-001001AN Coil, 220 uH
D300 None None 893-314937AC Diode, IN4937
SERVICE BULLETIN
PRODUCT: COMPUTER MONITOR
BULLETIN: MONITOR 95-008
MODEL: SAMTRON SC-428PT/L

Disclaimer: This information is provided “as is” without warranty of any kind
either expressed or implied, including, but not limited to, the implied
warranties of merchantability and fitness for a particular purpose.
REV 5-1
SERVICE BULLETIN
PRODUCT: Computer Monitor
BULLETIN: MON 97-001
MODEL: CQB4147
SUBJECT: Reduce Q404 Failure Rate Causing No Raster
BACKGROUND: Q404 fails when the monitor changes from the DPMS
Suspend mode back to Normal operation. Q415 is designed, in the circuit, to cut
off horizontal drive to the base of Q404. This is achieved by turning Q415 on in
the Suspend mode. In normal operation, Q415 is turned off. There is a delay in
turning Q415 off by approximately 15 ms. This will cause an abnormal pulse at
the base of Q404, causing damage to the transistor.
SOLUTION: The base current limiting resistance to Q415 has been changed by
decreasing the values of R200 and R461.
PARTS LIST:
ORIGINAL NEW
Location No. Part No. Description Part No. Description
R200 2001-000056 R-CF 4.7K, 1/6W 2001-000043 R-CF 1K, 1/6W
R461 2001-000056 R-CF 4.7K, 1/6W 2001-000029 R-CF 100 OHM, 1/6W

Disclaimer: This information is provided “as is” without warranty of any kind
either expressed or implied, including, but not limited to, the implied
warranties of merchantability and fitness for a particular purpose.
REV 5-1
SERVICE BULLETIN
PRODUCT: Computer Monitor
BULLETIN: MON 97-002
MODEL: CMH7379L
SUBJECT: To prevent whistling sound from occurring.
BACKGROUND: A whistling sound is created from harmonic noise generated between T402,
L402, and the main PCB near the Flyback Transformer.
SOLUTION: Add a piece of rubber to insulate the main PCB solder side from the bottom metal
shield. See Illustration below showing the section of the PCB where the rubber will be located.
PARTS LIST:
Part No. Description
BH61-30303A RUBBER

Disclaimer: This information is provided “as is” without warranty of any kind
either expressed or implied, including, but not limited to, the implied
warranties of merchantability and fitness for a particular purpose.
REV 5-1
SERVICE BULLETIN
PRODUCT: Computer Monitor
BULLETIN: MON 97-003
MODEL: CQB4147
SUBJECT: Improve the Horizontal Output Transistor Quality
BACKGROUND: The horizontal output for the CQB4147 has been changed as
of May 1, 1997. The BU2508DF, which had been used prior to this date, has
been failing intermittently due to a current surge from the 166 volt B+ line. The
current surge is caused mainly from the DPMS off mode recovery.
SOLUTION: The circuit has been improved by using a 2SC5149, which has a
higher hfe than the originally used BU2508DF.
PARTS LIST:
ORIGINAL NEW
Location No. Part No. Description Part No. Description
Q403 0502-000007 BU2508DF 0502-000005 2SC5149

Disclaimer: This information is provided “as is” without warranty of any kind
either expressed or implied, including, but not limited to, the implied
warranties of merchantability and fitness for a particular purpose.
REV8-1
SERVICE BULLETIN
PRODUCT: Computer Monitor
BULLETIN: MON 97-004
MODEL: CFX1577L
SUBJECT: Vertical Positioning Shifted Off Center
BACKGROUND: Q302 and R327 fail in the vertical positioning circuit. The
failure is caused by a current surge during power up and from the monitor
recovering from an extended period in the DPMS Suspend mode.
SOLUTION: Replace Q302, Q303, and R327 with different ratings. Production
went under these changes as of February 1, 1997. Observe the pin configuration
when replacing Q302.
PARTS LIST:
ORIGINAL NEW
Location No. Part No. Description Part No. Description
Q302 0501-000586 KSC945, 150mA 0502-000006 KSC1507, 200mA
Q303 0501-000008 KSC733C, 150mA 0501-000294 KSA708, 700mA
R327 2001-000526 R-CARBON, 1/6 W 2003-000590 MO, 2W, 22 ohm

Disclaimer: This information is provided “as is” without warranty of any kind
either expressed or implied, including, but not limited to, the implied
warranties of merchantability and fitness for a particular purpose.
REV 8-1
SERVICE BULLETIN
PRODUCT: Computer Monitor
BULLETIN: MON 97-005
MODEL: CMH7379L
SUBJECT: Q407 Failure Causing No Raster or Small Horizontal Size
BACKGROUND: Q407 fails due to a transient pulse and current when mode
switching from DOS to Windows. This occurs with a Matrox video card installed
in the computer.
SOLUTION: Add a sub-PCB assembly as in figures 1 and 2 and a snubbing
circuit for the horizontal output as in figure 3.
PARTS LIST:
ORIGINAL NEW
Location No. Part No. Description Part No. Description
NA NA NA BH92-50106J SUB-PCB ASSEMBLY
NA NA NA BH39-40355S 4 PIN CBF-HARNESS
NA NA NA 6003-000129 TAPTITE SCREW
NA NA NA 0401-000005 1N4148 DIODE
NA NA NA 0402-000012 UF4007 DIODE
NA NA NA 2003-000009 220 OMHS, 1 WATT

Figure 1
Top View of the Main Board

Figure 2
Bottom View of the Main Board

Figure 3
Snubbing Circuits

Disclaimer: This information is provided “as is” without warranty of any kind
either expressed or implied, including, but not limited to, the implied
warranties of merchantability and fitness for a particular purpose.
REV 8-1
SERVICE BULLETIN
PRODUCT: Computer Monitor
BULLETIN: MON 97-007
MODEL: CMB5477L
SUBJECT: Flyback Transformer Revisions
BACKGROUND: Samsung instituted new revision flyback transformers as of
October 24, 1996. The new flyback transformer will prevent intermittent no
raster conditions. The revised flyback transformers that have been applied to
the latest production runs will have resistance values changed in the x-ray
protection and the high voltage adjustment circuits.
SOLUTION: When replacing a flyback transformer refer to the parts list below.
The resistance values should be changed accordingly. If the resistance values
are different from the flyback transformers listed below, intermittent no raster or
shutdown conditions will exist. Refer back to the original parts list and
schematic located in the service manual for any flyback transformer without a
revision number or label on it.
PARTS LIST:
ORIGINAL NEW
Location No. Part No. Description Part No. Description
T402 BH26-10303V REV.04 FSA15A003
SAMSUNG BH26-10303V REV.05 & REV.06 FSA-15A003
SAMSUNG
R516 2004-001319 1/4W, 86k ohm 2004-001349 1/4W, 91k ohm
R411 2001-000054 1/4W, 3.9k ohm 2004-000899 1/4W, 4.7k ohm
R412 2001-000722 1/4W, 4.3k ohm 2004-000698 1/4W, 3.3k ohm

Disclaimer: This information is provided “as is” without warranty of any kind
either expressed or implied, including, but not limited to, the implied
warranties of merchantability and fitness for a particular purpose.
REV 8-1
SERVICE BULLETIN
PRODUCT: Computer Monitor
BULLETIN: MON 97-008
MODEL: CFG9637
SUBJECT: Video Pre-amp (LM1205) Failure Causing No OSD
BACKGROUND: The OSD blanking input stage of IC101 (LM1205) shorts to
the Vcc input stage due to CRT discharging and surge current.
SOLUTION: Add a 7.5V zenor diode between pin 13 of IC101 and ground
(cathode to pin 13 and anode to ground). Replace jumper wire JP104 with a 100
ohm ½ watt resistor. The resistor will act as a delay and improve the R,G,B
surge absorbers discharge effect. Replace the 300V spark gaps at each of the
Red, Green, and Blue cathodes of the CRT with 200V surge absorbers.
PARTS LIST:
ORIGINAL NEW
Location No. Part No. Description Part No. Description
NA NA NA 0403-000366 ZD 7.5V
JP104 NA JP104 2001-000028 R-CF(S), 100 ohm, 1/2W
SGR1 4715-000106 300V, Surge Absorber 4715-000102 200V, Surge Absorber
SGB1 4715-000106 300V, Surge Absorber 4715-000102 200V, Surge Absorber
SGG1 4715-000106 300V, Surge Absorber 4715-000102 200V, Surge Absorber

Disclaimer: This information is provided “as is” without warranty of any kind
either expressed or implied, including, but not limited to, the implied
warranties of merchantability and fitness for a particular purpose.
REV 8-1
SERVICE BULLETIN
PRODUCT: Computer Monitor
BULLETIN: MON 97-009
MODEL: CMB5477L
SUBJECT: Video Pre-amp IC101 (LM1207) Failure
BACKGROUND: IC101 becomes damaged from arcing within the CRT during
electronic discharge.
SOLUTION: Add a 300V spark gap in between the G1 grid of the CRT and
ground. This will aid in reducing the discharge effect from the CRT.
PARTS LIST:
ORIGINAL NEW
Location No. Part No. Description Part No. Description
NA NA NA 4715-000106 300V, Surge Absorber

Disclaimer: This information is provided “as is” without warranty of any kind
either expressed or implied, including, but not limited to, the implied
warranties of merchantability and fitness for a particular purpose.
REV 8-1
SERVICE BULLETIN
PRODUCT: Computer Monitor
BULLETIN: MON 97-010
MODEL: CQA4147, CQB4147
SUBJECT: No Raster
BACKGROUND: D618, which is the rectifier diode for the 166V line, burns due
to a reverse peak voltage that occurs when power is turned off.
SOLUTION: A snubbing capacitor must be added in parallel with D618 in order
to prevent this from occurring. This capacitor should be added to all CQB and
CQA chassis as a preventative maintenance.
PARTS LIST:
ORIGINAL NEW
Location No. Part No. Description Part No. Description
C643 NA NA 2201-000012 C-CERAMIC DISK, 220pf,
10%, 1KV