NEC DTE-25G5THS User manual

September, 2002
NEC Corporation
Service manual
59/68 Cm STEREO Color Television
MODEL : DTE-25G5THS
DTE-29G5TH
FS-59T90
FS-68T90
DTE-25G4ZH
DTE-29G4ZH
FS-59V81
FS-68V81
CHASSIS : CP-785A
S/M No. : TCP785AEFR1

Contents
1 - Main features
2
1-1 Specifications 2
1-2 External Terminals 2
1-3 Channel table 4
2 - Safety instruction 7
3 - Alignment instructions 8
3-1 Microcontroller configuration : Service mode 8
3-2 Microcnotroller configuration : Option 8
3-3 TV set Alignment 10
4 - IC description 12
4-1 TDA936x TV signal processor - TXT with embedded -Controller 12
4-2 MSP34 Multistandard Sound Processor 19
4-3 TDA894x J Stereo Audio Amplifier 23
4-4 TDA835x J Vertical Amplifier 24
4-5 TDA6107Q 26
4-6 24C08 8 K bit EEPROM 27
4-7 STR-F665X 28
5 - Circuit description 30
5-1 Block diagram 30
5-2 IF 34
5-3 Source switching 35
5-4 -Controller I/O pin configuration and function 35
5-5 Sound processing 36
5-6 Sound amplification 37
5-7 Vertical deflection 38
5-8 Power supply (STR-F6654) 39
5-9 TV start-up, TV normal run and stand by mode operations 43
6 - Service parts list 50
6-1 PCB Difference Part (PCB change of FS-xxT90) 51
6-2 CRT Difference Part 59
6-3 Function & Cabinet Difference Part 60
6-4 All Electrical Parts List 61
7 - Compaitible Components List for FS-xxT90, xxV81
8 - Exploded view 83
9 - PCB Layout 84
9-1 Old Main PCB (4859804393) 85
9-2 New Main PCB (4859806493) 86
9-3 Control PCB (4859833214) 87
10 - Circuit Diagram 88
10-1 Old Main PCB 88
10-2 New Main PCB & Control PCB 89
-1--1-

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Service Manual CP-785A
1-1 Specifications
1-2 External Teminals
1-2-1 Input 2 : Rear RCA
TV standard PAL, - B/G, H
Sound system NICAM B/G
FM 2Carrier B/G
Power consumption 25” : 113W approx.
29” : 118W approx.
Sound Output Power 25” : 5W x 5W (at 60% mod, 10% THD)
29” : 5W x 5W (at 60% mod, 10% THD)
Speaker 25” : 7W 8 ohm x 2
29” : 7W 8 ohm x 2
Teletext system 10 pages memory FASTEXT (FLOF or TOP) : Option
Aerial input 75 ohm unbalanced
Channel coverage Off-air channels, S-cable channels and hyperband
Tuning system frequency synthesiser tuning system
Visual screen size 25” : 59 Cm
29” : 68 Cm
Channel indicatio On Screen Display
Program Selection 100 programmes
Aux. terminal INPUT1(SCART or RCA)
- SCART : Audio / Video In, S-VHS In(with cable)
- RCA : Audio / Video In. (SVHS : disable)
INPUT2(RCA) : Audio / Video In
OUTPUT(RCA) : TV OUT
Headphone jack (3.5 mm) on front of cabinet
Remote Control Unit R-44N08(RD-D90) for with Teletext
R-44N09(RD-085) for with Teletext
Pin Signal Matching value
1(Yellow) Video Input 1.0 Vpp+/- 3dB, Impedance 75 ohm
2(White) Audio Input Left 0.5 Vrms, Impedance > 10k ohm
3(Red) Audio Input Right 0.5 Vrms, Impedance > 10k ohm
1-2-2 Output : Rear RCA
Pin Signal Matching value
1(Yellow) TV Video 1.0 Vpp+/- 3dB, Impedance 75 ohm
2(White) TV Audio Left 0.5 Vrms at RF Sound FM 54%Mod.(27kHz dev.)
3(Red) TV Audio Right 0.5 Vrms at RF Sound FM 54%Mod.(27kHz dev.)
1-2-3 Input1 : Rear RCA or Scart
-RCA Jack : Input1 (S-VHS not available)
Pin Signal Matching value
1(Yellow) Video Input 1.0 Vpp+/- 3dB, Impedance 75 ohm
2(White) Audio Input Left 0.5 Vrms, Impedance > 10k ohm
3(Red) Audio Input Right 0.5 Vrms, Impedance > 10k ohm
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Service Manual CP-785A
- SCART (21pin Euro Scart) : Input1 & S-VHS input
Pin Signal Matching value
1 N.C.
2 Audio Input Right 0.5 Vrms, Impedance > 10 kΩ
3 N.C.
4 Audio Earth
5 Earth
6 Audio Input Left 0.5 Vrms, Impedance > 10 kΩ
7 N.C.
8 N.C.
9 N.C.
10 N.C.
11 N.C.
12 N.C.
13 N.C.
14 Earth
15 Chroma Input +/- 3dB for a luminance signal of 1 Vpp
16 N.C.
17 Earth
18 Video In Earth
19 N.C.
20 Video Input / Y Input 1 Vpp +/- 3dB, Impedance 75 ohm
21 Common Earth

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Service Manual CP-785A
1-3 Channel table
FREQUENCY TABLE CP-785A
CH AUSTRALIA N/Z˅land
C00 46.25
C01 57.25
C02 64.25
C03 86.25
C04 95.25
C05 102.25
C5A 138.25
C06 175.25
C07 182.25
C08 189.25
C09 196.25
C10 209.25
C11 216.75
N01 - 45.25
N02 - 55.25
N03 - 62.25
N08 - 203.25
N09 - 210.25
N10 - 217.25
- - -
C21 471.25
C22 479.25
C23 487.25
C24 495.25
C25 503.25
C26 511.25
C27 519.25
C28 527.25
C29 534.25
C30 541.25
C31 548.25
C32 555.25
C33 562.25
C34 569.25
C35 576.25
C36 583.25
C37 590.25
C38 597.25
C39 603.25
C40 610.25
C41 617.25
C42 624.25

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Service Manual CP-785A
CH AUSTRALIA N/Z˅land
C43 631.25
C44 638.25
C45 645.25
C46 652.25
C47 659.25
C48 666.25
C49 673.25
C50 680.25
C51 687.25
C52 694.25
C53 701.25
C54 708.25
C55 715.25
C56 722.25
C57 729.25
C58 736.25
C59 743.25
C60 750.25
C61 757.25
C62 764.25
C63 771.25
C64 779.25
C65 786.25
C66 793.25
C67 800.25
C68 807.25
C69 814.25
C70 -
C71 -
C72 -
C73 -
C74 -
C75 -
C76 -
C77 -
S01 105.25
S02 112.25
S03 119.25
S04 126.25
S05 133.25
S06 140.25
S07 147.25
S08 154.25
S09 161.25
S10 168.25
S11 231.25

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Service Manual CP-785A
CH AUSTRALIA N/Z˅land
S12 238.25
S13 245.25
S14 252.25
S15 259.25
S16 266.25
S17 273.25
S18 280.25
S19 287.25
S20 294.25
S21 303.25
S22 311.25
S23 319.25
S24 327.25
S25 335.25
S26 343.25
S27 351.25
S28 359.25
S29 367.25
S30 375.25
S31 383.25
S32 391.25
S33 399.25
S34 407.25
S35 415.25
S36 423.25
S37 431.25
S38 439.25
S39 447.25
S40 455.25
S41 463.25

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Service Manual CP-785A
2 - Safety instruction
WARNING: Only competent service personnel may carry out work involving the testing or repair of this
equipment.
X-RAY RADIATION PRECAUTION
1. Excessive high voltage can produce potentially hazardous X-RAY RADIATION. To avoid such
hazards, the high voltage must not exceed the specified limit. The nominal value of the high voltage of
this receiver is 26~28 KV (25” - 29”) at max beam current. The high voltage must not under any
circumstances, exceed 29.5 KV (25") or 31 KV (29"). Each time a receiver requires servicing, the
high voltage should be checked. It is important to use an accurate and reliable high voltage meter.
2.The only source of X-ray Radiation in this TV receiver is the picture tube. For continued X-ray
RADIATION protection, the replacement tube must be exactly the same type tube as specified in the
parts list.
SAFETY PRECAUTION
1. Potentials of high voltage are present when this receiver is operating. Operation of the receiver outside
the cabinet or with the back board removed involves a shock hazard from the receiver.
1) Servicing should not be attempted by anyone who is not thoroughly familiar with the precautions
necessary when working on high voltage equipment.
2) Discharge the high potential of the picture tube before handling the tube. The picture tube is highly
evacuated and if broken, glass fragments will be violently expelled.
2. If any Fuse in this TV receiver is blown, replace it with the FUSE specified in the Replacement Parts
List.
3. When replacing a high wattage resistor (oxide metal film resistor) in circuit board, keep the resistor 10
mm away from circuit board.
4. Keep wires away from high voltage or high temperature components.
5. This receiver must operate under AC 240 volts, 5O Hz. NEVER connect to DC supply or any other
power or frequency.
PRODUCT SAFETY NOTICE
Many electrical and mechanical parts in this equipment have special safety-related characteristics. These
characteristics are often passed unnoticed by a visual inspection and the X-ray Radiation protection
afforded by them cannot necessarily be obtained by using replacement components rated for higher
voltage, wattage, etc. Replacement parts which have these special safety characteristics are identified in
this manual and its supplements, electrical components having such features are identified by designated
symbol on the parts list. Before replacing any of these components, read the parts list in this manual
carefully. The use of substitutes replacement parts which do not have the same safety characteristics as
specified in the parts list may create X-ray Radiation.

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Service Manual CP-785A
3 - Alignment instructions
3-1 Microcontroller configuration : Service mode
To switch the TV set into service mode please see instruction below.
1 - Select pr. number 91
2 - Adjust sharpness to minimum value and exit all menu.
3 - Quickly press the key sequence : RED - GREEN - menu
To exit SERVICE menu press menu key or Operate(Std By) key.
In Service Mode press “OK” to stop the microcontroller i.e. the I2C bus is free and the set can be controlled by
external equipment. Press “OK” again to allow the microcontroller to control the set again.
3-2 Microcontroller configuration : Option
Section Items BareDATA 29ˉ25ˉ21ˉREMARK
G5TH G4ZH G5THS G4ZH
AGC 32 38 38 38 38 38
BIAS R/G 31/31 31/31 31/31 31/31 31/31 31/31 old micom : 8/8
DRIVE R/G/B 32/32/32 32/32/28 32/32/28 32/32/32 32/32/32 32/32/32
H-PARALLEL 31 36 36 32 32 32
H-BOW 42 34 34 35 35 35
For H-SHIFT 25 30 30 30 30 27
Adjustment V-SLOPE 32 35 35 35 35 35
(Variable) V-Amplitude 39 19 19 30 30 27
V. S-Correction 13 27 27 25 25 23
V SHIFT 32 34 34 34 34 45
H-WIDTH 32 37 37 57 57 33
EW Parabola 32 20 20 17 17 0
Up-Conner 32 32 32 42 42 32
Dn-Conner 32 32 32 42 42 32
EW Trapezium 32 29 29 31 31 29
Option 04 04 04 04 04 04 0,1,2,3 : For D/W Remote controller
4,5,6,7 : For NEC Remote controllerˉ
CH Lock
or OFF OFF OFF OFF OFF OFF “Hotel Lock” will be changed to “CH Lock”
HOTEL Lock
HOTEL Max Vol
For or 15 43 43 43 43 43 “
Hotel Max Vol” will be changed to “Max Vol”
Function Max VOL
Change Colck Pr. 01 07 07 07 07 07 change the reference channel
(OPTION) for Automatic clock setting
SVHS ON ON OFF ON OFF OFF OFF : disable S-VHS Input
AV START OFF OFF OFF OFF OFF OFF “AV START” is add
KEY LOCK OFF OFF OFF OFF OFF OFF “KEY LOCK” is add
SCREEN 24 31 31 33 33 35 each CRT has different Adjusting point

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Service Manual CP-785A
Lock Function Name Description Applied CPU Remark
Models Version
- Channel Setting : Enable / Disable
Current - Volume Limit (Hotel Max Vol) : Enable / Disable FS-59T90 These current Lock fuction
Lock - When this function is active, It is impossible to change FS-68T90 DW9365-CH1 will be change to New Lock Fuction.
Function Hotel Lock ON / OFF the channel data (can not enter the INSTALL menu) & PF51T31
the sound can be limited by
ˈHotel Max Volˉ.
- This Function is available When
ˈHotel Lockˉis on
Hotel (This function is depend on Hotel Lock Function)
Max. Volume 00 ~ 43(max.) - When Hotel Lock is off , the sound dose not limited.
- Channel Setting : Impossible / Possible - Each Lock Function is independence
CH Lock ON / OFF - The former
ˈHotel modeˉhas been removed and added
ˈCH lockˉ- It is possible to change the features by
- When this function is active, It is impossible to change combination of each function
New the channel data (can not enter the INSTALL menu) FS-59V81 - We will apply these new lock fuction to
Lock - Max Volume is limited. FS-68V81 current TEXT micom.
Function - Even if
ˈCH lockˉis not active the sound can be DW9365-CH2
Max Vol 00 ~ 43(max.) limited by the service function
ˈMax Volˉ. (FS-59T90) DW9385-CH1 - Examlpe)
- In case of virgin EEPROM, the default setting is 43 (Max). (FS-68T90) CH lock=ON, Max Vol=20 - In normal, the
ˈMax. Vol.ˉmust be 43 (PF51T31) ==> CH setting = Disable
- When
ˈVA startˉis active, the set always start in AV1 mode Volume Limit : under 20
AV Start ON / OFF (main AC switch on/off & remote controller on/off). Max. Vol=20, AV start=ON, Key Lock=ON
- In case of virgin EEPROM, the default setting is OFF. ==> Volume Limit : under 20
Key Lock ON / OFF - When active the local keyboard cannot be used. Tv is always turn on at AV1 mode
- In case of virgin EEPROM, the default setting is OFF. Front local keys are not operate
Change of Lock Function (1) Model - New AV Stereo Model (FS-xxV81, DTE-xxG4ZH) will be applied the new lock function from 1st MP. - Current Model (FS-xxT90, DTE-xxG5THx) will be changed to new lock function when the CPU software is changed (TDA9365 : DW9365-CH1 ==> DW9365-CH2) (2) Details
* Note : These Function is changed only Service Mode not Factory mode. So you must use the user˅s remote controller
- Change the PR. No. to 91 ==> change the sharpness to 00(min) in Picture control Menu ==> Exit the User control Menu ==> Press the [RED],[GREEN],[MENU] quickly - Then the Service Menu is appeared.