Prestigio PAP5000 DUO User manual

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PAP5000 Maintenance Manual
Table of Contents

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1. Circuit diagram instruction ...........................................................................................................3
1.1 Main board explored view..............................................................3
1.2 Detailed Description of Circuit Chart.............................................5
1.3 Base band circuit.............................................................................5
1.4 Function circuit...............................................................................6
2．Fault maintenance.......................................................................................................................8
2.1 fault repair.......................................................................................9
3 Trouble shooting and flow chart ..................................................................................................13
3.1 Unable to power on the handset....................................................13
3.2 No ring tone..................................................................................14
3.3 LCD display fault..........................................................................15
3.4 Charging fault ...............................................................................16
3.5 Camera fault..................................................................................17
3.6 Fail to identify SIM card...............................................................18
3.7 MIC fault.......................................................................................19
3.8 Keypad fault..................................................................................20
3.9 Receiver fault................................................................................21
3.10 Vibrate fault ................................................................................22
3.11 FM fault.......................................................................................23
3.12 No signal.....................................................................................24
3.13 Failure to identify T-flash card ...................................................25
3.14 Earphone fault.............................................................................26
3.15 Unable to use USB......................................................................27

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1. Circuit diagram instruction
1.1 Main board explored view
MTK6577
USB connector
RF transceiver
Earphone connector
Touch IC
G_PA
FLASH
G_RF
PMIC
W_PA
W_RF
KB connector
Back camera connector Front camera connetor 32.768 crystal

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T card connector
SIM card connector Battery connector LCD connector
Backup battery
TP connector
MT6620 chip

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1.2 Detailed Description of Circuit Chart
1.3 Base band circuit
Base Band adopts MT6577
Keypad
SIM1
CA
M

T
‐
card
SIM2
lightsensor
W/F/G/B4in1chip
RFfilter
U205
RFfilter
U204
R
F
P
A

U202
R
F
P
A

U203
R
F
P
A

U101
RFfilter
U104
RFfilter
U102

RF
transceiver

U201

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MT6577 internal schematic block diagram
1.4 Function circuit
GPS、WIFI、BT、 FM circuit:
MT6577
MT6620
Module
FM
GPS
BT
WIFI
AN
G-senso
r
PS/ALS
CTP

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Dual SIM circuit:
T-Flash Card circuit
CAM

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2．Fault maintenance
Note:
The PCBA repairing is a very important procedure during the final production of cellular phones.
The speed and quality of repairing decides the yield and production Tefficiency. The TTrepair idea is
very important for a good repairing technician. Make sure not to heat a board right away once a
phone reaches at hand.

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2.1 fault repair
Base band
MTK uses relatively high integration and has limited peripheral independent elements. Check
whether there is any additional element, missing or wrong element before hot air gun is used. If
visual detection fails to find problem, use some equipments to find failure positions。
(1) Below 20MA: indicates that power starts working but the next action is not performed. The
cause can be incomplete soldering or damage in power management, CPU or 26M circuit.
(2) 20~25MA: the cause can be: there is no download software; software functions abnormally; or,
CPU cannot read or execute software normally.

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(3) 30~90MA: if the software, 26M and 32K are all normal, the cause can be incomplete soldering.
Check CPU and Flash
Startup process：
When the Power-On button is pressed, PWRKEY will detect a low voltage. The internal PMIC
will turn on the LDOs which provide power-supply to base band 30ms later; then the RESET
circuit of the PMIC will generate the reset signal 200ms later to make the base band chip run the
power-on software
Fail to download
Make sure that the download current of main board is normal and important I/O
interfaces including U301/CPU and U601/Flash are normal.

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Bluetooth failure
Please refer to the details of Bluetooth circuit description in Part 1. First perform
visual examination to check whether there are missing pieces on related circuits or
significant deviation. Then perform circuit analysis according to the maintenance
process.

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3 Trouble shooting and flow chart
3.1 Unable to power on the handset

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3.2 No ring tone

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3.3 LCD display fault

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3.4 Charging fault

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3.5 Camera fault
Check camera for damage
Failure to use camera
OK
Replace new camera
Yes
Check if camera is soldered or
assembled well
No
Yes Solder camera connector
or Re-assemble camera
Check camera circuit for fault
No
Yes Mark the mainboard
with analysis result
Replace new mainboard
No

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3.6 Fail to identify SIM card

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3.7 MIC fault

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3.8 Keypad fault
Check : DOME is pasted and
keymat is assembled correctly
Keypad doesn’t work
correctly
OK
Paste the DOME or
assemble keymat again
Yes
Is there any dirty on keypad
surface?
No
Yes Clean keypad surface and
test
No
Replace new mainboard
No
Is sidekey soldered well?
No short circuit Yes Solder or replace sidekey