TVGo DVB-T31 Service Manual

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Service Manual

TVGo DVB-T31

Version: 1.0

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Service Manual TVGo DVB-T31

Content

Chapter1. Introduction a. System block diagram3 b. Power block diagram4

Chapter2. Remove and Replacement a. Remove screw.5 b. Open top cover..7 c. Remove front panel8 d. Remove screw on board and rear panel9 e. Remove board from case.10

Chapter3. Testing Procedure a. Power checking flow chart..11 b. Boot failure 24 c. SCART TV output 29 d. SCART Video & audio input ..35 e. Audio L/R SPDIF .38 f. Tuner .41

Chapter4. Trouble shooting Guide.47

Chapter5. Parts list.49

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Chapter1. Introduction a. System block diagram.

4

Service Manual TVGo DVB-T31 b. Power block diagram.

Powerboard100-220V in

15V6.5V3.3V

IC10078L12

IC1021117-5.0

IC1031117-5.0

12V

5VD

5V

3V3

DiodeD100 DT2

1.8V

DiodeD101 2V5

3.3V_TU

3.3VM

3.3VEM

5


Chapter2. Remove and Replacement a. Remove screw

Fig.(1)

Fig.(2)

Remove

Remove

6


Fig.(3)

Remove

7


b. Open top cover

Fig.(4)

Fig.(5)

Open

8


c. Remove front panel

Fig.(6)

Fig.(7)

Pull it up

Push it down

9


d. Remove screw on board and rear panel

Fig.(8)

Fig.(9)

Remove 7 screws

Remove 7 screws

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e. Remove board from case

Fig.(10)

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Chapter3. Testing Procedure (a)Power checking flow chart

12


(a-1) Check 15V output

Fig.(11)

Fig. (12)

15V output

13


Fig.(13)

Replace T1

14


(a-2) Check 6.5V output

Fig.(14)

Fig. (15)

6.5V output

15


Fig.(16)

Replace T1

16

Service Manual TVGo DVB-T31 (a-3) Check 3.3V output

Fig.(17)

Fig. (18)

3.3V output

17


Fig.(19)

Replace T1

18

Service Manual TVGo DVB-T31 (a-4) Check 5V output

Fig.(20)

Fig. (21)

Test here 5V out

19


Fig.(22)

Replace IC102

20


Fig.(23)

Fig. (24)

Test here 5V out

21


Fig.(25)

Replace IC103

22


Fig.(26)

Fig. (27)

Test here 12V out

23


Fig.(28)

Replace IC100

24

Service Manual TVGo DVB-T31 (b)Boot failure debug

Please do the Power checking first.

Start

Boot Failure

Check 27MHz

ReplaceIC300

DownloadSoftware

ReplaceIC302

END

SoftwareDownloadNot finish

ReplaceIC301

25


(b-1) Check 27MHz output

Fig.(29)

Fig.(30)

27MHz out

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Fig.(31)

Replace IC300

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(b-2)Download software. If we want to update the software of DUT, RS232 ports must be well connected first.

As shown in the following picture. Master must be powered on first and then turn on the DUT.

Fig.(32)

Fig.(33)

Replace Flash IC302

DUT (Power On after master) Master (First Power On)

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(b-3) Software download not finished 10% 20%.......

Fig.(34)

Fig.(35)

Replace SDRAM IC301

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(C)SCART TV output

SCARTTV out

NG

CheckCVBS

out

Replace Q400Q409

CheckRGB R

out

ReplaceQ501

CheckRGB G

out

ReplaceQ502

CheckRGB B

out

ReplaceQ503

END

Check Audio

Out

R channelOutput NG

Replace Q201

L channelOutput NG

Replace Q203

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(c-1) Check CVBS out Measure the video signal at the output ports (collector) of transistor Q409 and Q400. The video signal will be similar to the fig. (31).

Fig.(36)

Fig.(37)

Check CVBS out

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(c-2) Check RGB video signal : R signal

Measure the output port of Q501

Fig.(38)

Fig.(39)

R signal

32


(c-3) Check RGB video signal : G signal Measure the output port of Q502

Fig. (40)

Fig.(41)

G signal

33


(c-4) Check RGB video signal : B signal Measure the output port of Q502

Fig. (42)

Fig.(43)

B out

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(c-5) Check R&L channel audio output Measure the output signal at the collector terminal of Q203 and Q201

Fig. (44)

Fig. (45)

R channel L

channel

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(d)SCART Video in debug.

SCARTVideo in

NG

CheckCVBS

in

Replace Q407

END

Check Audio

in

R channelIn NG

ReplaceIC400

R channelIn NG

Replace IC400

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(d-1) Check CVBS input Measure the input video at the base terminal of transistor Q407

Fig. (46)

Fig. (47)

CVBS IN

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(d-2) Check R L channel audio input Measure the input audio signal at pin2 and pin5 of IC400, as shown in the picture.

Fig. (48)

Fig. (49)

R/L audio input

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(e)Audio L/R SPDIF

RCAAudio

NG

R channelout

ReplaceQ200

L channelout

ReplaceQ202

END

SPDIFout

Replace Q701

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(e-1)Check L/R audio output The output ports (collector terminal) of Q200 and Q202

Fig. (50)

Fig. (51)

R channel L

channel

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(e-2) Check SPDIF output Check the output signal at the emitter terminal of Q701

Fig. (52)

Fig. (53)

SPDIF output

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(f) Tuner

STB can notLock signal

Check Tuner

5V

ReplaceL104

Check Tuner3.3V

ReplaceL107

CheckTuner1.8V

ReplaceDT2

ReplaceTuner

Signal Lock

Display OK

END

ReplaceIC300

42


(f-1) Checking 5V

Fig. (54)

Fig. (55)

5V

43

Service Manual TVGo DVB-T31 (f-2) Checking 3.3V

Fig. (56)

Fig. (57)

3.3V

44

Service Manual TVGo DVB-T31 (f-3) Checking 1.8V

Fig. (58)

Fig. (59)

1.8V

45

Service Manual TVGo DVB-T31 (f-4) Replace Tuner

Fig. (60)

Replace it

46


(f.5) Tuner lock and Display fail

Fig. (61)

Replace IC300

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Chapter4. Trouble shooting Guide Problems Condition Probable Reasons Solutions

Boot Failure The power indicator LED is on, but no video/audio output

(1) 3.3V and 2.5V fail (2) IC300 fail (3) SDRAM fail (4)flash fail

(1)Power checking (2)change IC300 (3)change SDRAM (4)change Flash

SCART TV out debug (1)SCART TV CVBS output is NG

(1)Transistor Q400,Q409 (2)Switch IC400

(1)check amp. Q400,Q409 (2)check switch IC400

(2)SCART TV RGB output is NG

(1) Amp. is disable (2)Main chip,IC300

(1)Check video amp. Q501,Q502,Q503 (2)Check main chip,IC300

(3)SCART TV 4:3/16:9 switch

(1)Transistor switch is disable (2)Main chip,IC300

(1)Check the transistor switch whether the logic level translation is right or not. Q404,Q408 (2)Check the logic level of main chip,IC300

(4)SCART VCR output (1) A/V amp. (2)A/V switch (3) Main chip ,IC300

(1) check video amp. Q409,Q401, Q400& video switch ,IC400. (2)Check audio amp. Q201,Q203 and IC200 ,audio switch IC400 (3)check the main chip whether it output the A/V signal or not .

(5)SCART VCR input (1)A/V signal source is not functional properly. (2)The signal used to switch the A/V mode is not assert.

(1)Check the A/V source (2)Check the logic level at pin ?SLOW S/W? (3)Make sure the transistor Q403,Q405 are functional.

Audio L/R output?SPDIF (1)Audio L/R output is NG (1)Audio amplifiers are disable. (2)Maybe the main chip, IC300, is disable.

(1)Check audio amp. Q201,Q203 and IC200 ,audio switch IC400 (2)check the main chip whether it output the A/V signal or not .

(2)SPDIF is disable (1)Inner source is disable (2)Q701 is destroyed.

(1)Check the signal at pin57 of IC300 is outputted or not. (2)Make sure the transistor Q701 is still functional.

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Tuner circuit Tuner can not lock the signal

(1)The parameters are not set correctly. (2)Control signals are not correctly or disable. (3)Tuner is destroyed (4)The main chip is destroyed.

(1)Check all the parameters are properly set. (2)Check all the power supply used in the Tuner. (3)Measure the control signals and check whether they are transmitted or not. (4)If the problems still can not be solved, the tuner should be changed. (5)If above problems still exit, the main chip , IC300, can be changed.

RS232 Data can not be transmitted or received through the port.

(1)RS232 chip is disable (2)The data bus is not well connected to the main board (3)Without power supply

(1)Make sure the connection between main board and the data bus is well. (2)Make sure the power is correct (3)Check the signal at the input port of RS232 (4)If all above are OK, RS232 chip can be changed.

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Chapter5. Parts list Location NUM.

Description Part number

T1 XFMR RF JW0419 ?? 42041-00033-001 IC100 IC D DIP REG 78L12 TO92B CJ 65612-00007 IC102 IC D DIP REG AZ1117T-5.0 TO220 UTC 65612-00067 IC103 IC D DIP REG AZ1117T-5.0 TO220 UTC 65612-00067 IC300 IC D SMD CPU STI5518BQC 65111-00068 IC301 IC D SMD MEM A2S64S40DTP-G7 PSC 65211-00186 IC302 IC D SMD MEM A29L800TV-70 AMIC 65211-00202 IC400 IC D SMD LOG HEF4053BT SO16 Philips 65311-00007 Q200 XSTR SMD NPN 2S1623 SOT-23 NEC 62111-00008 Q201 XSTR SMD NPN 2S1623 SOT-23 NEC 62111-00008 Q202 XSTR SMD NPN 2S1623 SOT-23 NEC 62111-00008 Q203 XSTR SMD NPN 2S1623 SOT-23 NEC 62111-00008 Q400 XSTR SMD NPN 2S1623 SOT-23 NEC 62111-00008 Q407 XSTR SMD PNP 2SA812 SOT23 NEC 62112-00002 Q409 XSTR SMD PNP 2SA812 SOT23 NEC 62112-00002 Q501 XSTR SMD PNP 2SA812 SOT23 NEC 62112-00002 Q502 XSTR SMD PNP 2SA812 SOT23 NEC 62112-00002 Q503 XSTR SMD PNP 2SA812 SOT23 NEC 62112-00002 Q701 XSTR SMD NPN SMBT3904 62111-00013 L104 RES SMD 0805 0R 5% 51014-0000J L107 RES SMD 0805 0R 5% 51014-0000J TN100 P/PARTs TUNER UTB-002NH PESI 81002-90403 DT2 DIO DIP G 1N4002 61121-00011

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TVGo DVB-T31 Service Manual