Tyler TTV701-7 Service Manual

Ser v i c e m an u al
四、DTV no signal trouble shooting steps:
Select the local color system and sound system, then
start auto channel scanning
N O
Whether U6(R840) 11,18，24 circuit
+3.3V voltage normal.
Whether the circuit from
U15 104 pin to U6(R840) 11,18，24 pin
NO
normal?
YES
Check if the circuit from U15 58,59 pinto
component
U6(R840) 6、7 pin is normal.
NO
Replace related component
YES
When channel scanning, check if the 48 pin voltage of U15 changed on 0-3.3V range.
NO
Check the power supply of
51/52 pin and replace U15
YES
U15 49/50 pin and U6(R840) 17、16 pin is normal
Check if the component of
NO
Replace the related components
YES
Replace U15 or U6
4
一、No sound, no image, blank screen trouble shooting steps:
Whether the power light is on?
NO
See 2nd
W het her t he
phenomenon: blank
I C 2( ETA1483) +5Vpow er out put
screen
nor m al ?
maintenance steps
YES
Check the electrical level of U11
（SC61A05）from 1st pin is low
NO
NO Test battery
Check whether the 12V input voltage
electrode ： if have 4.2V
of IC2 (ETA1483)'s 2nd pin is normal
circuit is normal ,otherwise
replace U11
YE S
Check the circuit of U11 from 1 pin to the LED light.
And replace indicator lamp.
NO YES
Repair or replace the circuit
(ETA1483)
Check DC input jack and
AC adapter 12V
1
五、AV input no image no sound
Check if AV cable is normal?
N O
Replace AV cable
YES
Check if AV input socket is normal?
NO
Replace AV input socket
YES
If no sound, check Check AV input socket circuit from audio frequency to
,
U15 34/35/36/36 pin； No image, check if video frequency to the external
components of
components of U15 28, 29 pin is normal
NO
Replace the related components
U15
YE S
Replace U15
5
Blank screen t r oubl e shoot i ng st eps:
二、
Check the cathode of DI1(IN5819) if there have 10V voltage
Red ligh t on
Check
NO
UI1(G5121)from the 6
NO Whether the green light on pin have 5V voltage
YES
when press POWER
button.
YES
Check Q12
base
Test the power supply of
If it is a
electrode
U15(MSD3393) 3.3V/1.8V/1.2 is
high
normal electrical level
positive
Check the
related
No
NO
abnormal
circuit.
YES YES
of IC2
Check U9 software and Y2
crystal vibration circuit
，or
Check the circuit from
U15(MSD3393)
emitter electrode to back light, and
malfunctions.
replace back light
六、Snow screen/image not clear
Whether the cable of LCD screen loose?
Check if power supply -10V/+15V/+10V/+3.3V/5V on PCB sockets
are normal
the external
Check if the circuit from PCB socket to U15 (MSD3393) is normal
LCD screen abnormal.
三、Has image, no sound/low sound/distortion
Check the circuit from
NO U15(MSD3393) of the 133th
YES
pin to UI1(G5121) of the 6th pin
YE S
Replace speaker
Check the UI1(G5121) peripheral circuit
And replace UI1
Check the circuit from Q12 base electrode
to U15(MSD3393) of the 109 pin and
replace U15
Q12
2
七、USB not reading
Whether the socket normal?
YES
Tighten the cable.
YES
NO
Replace the socket.
N O
八、SD card not reading
Check the abnormal power supply circuit.
YES
Check if the socket is ok?
YES
Replace the socket.
NO
Check the abnormal circuit.
Test U14（MA8121K）18 pin if there have 5V power supply
YES
Repair the components from U14 23,24 pin to
6
Whether the speaker open circuit?
Maximum volume，on USB/SD reading status, Use the
multimeter to test the pin 3/8 of U13 （SL6699） ,whether
the speaker has noise.
No
No
Test U13 peripheral
components or replace U13
YES SL6699
Check the the 3/8 pin of U13
component from
to the pin 47/46 of U15，or replace U15
（MSD3393）
3
Test USB ① pin 5V power, check the circuit
NO
from USB ? ? to U15(MSD3393)'s 123,124 pin 2 3
NO
Check the power supply of
USB socket and other
component.
YES
Replace U15 (MSD3393)
Test SD socket each pin to the related route
NO
of U14（MA8121K）is Ok.
NO
Maintenance related corresponding circuit
YES
NO
Repair the related circuit
components from U15 110 pin to
YES
U14 18 pin.
U15 125，126 pin ，or replace U14、U15
7