JBL DVD600, Service Manual

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Troubleshooting Model : DVD600
1) Power. : When the ST/BY +5V of Front is transmitted to Power control port, the power of SMPS will be switched. And
unit turns on.
l
Check point : Power control port : CP214, 1pin
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Actually the input power is +3.5V, and if the unit does not turn on, all the power which supplies for Main is OFF.
2) Communication between Front CPU and STI5505
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Check point : CN208 & RXD/TXD port.
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When the Main Board system is initializing, Sti5505 dispatches data to Front CPU in order to wake it up.
l If the 1)power and 2)communication between Front CPU and Sti5505 are normal, but still there are Open/short
errors, so we call “ Power on” error, it because can not wake up Front CPU.
! RXD/TXD : Receiving / Transfer data port (Main = RXD, Front TXD at PCB)
3) Operation of STI5505
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Checking of each RAMs (Flash/DRAM
à
SDRAM) / EEPROM. => At this time, SCL/SDA should be High. If they
are low, the Sti5505 is not waken up.
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In case of Sti5505 does not wake up properly, Main clk (27.0MHz) is normal, but SDRAM clk is not normal.
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Check point : R350
l When initialize MECHA by reset, the CPU of Front-end is in initial operation.
(Pick up down
à
rotating Roulette/ sensing
à
Disc sensing
à
Roulette fixed
à
Pick up
à
ST/BY mode )
4) Main and Flash reset
l Check point : C312
5) If you find any problems for operation initializing , after being satisfied above condition,
need to check Mecha control line
l Check point : CP206, power and connection including soldering.
6) Test screen (color bar) / initial screen (stop screen : Vendor Logo screen)
l Test screen : All data but Logo screen is taken care by SDRAM.
à
Also you can easily check with using 2keys on Front Panel. (! Already issue data regarding these two keys)
l Also, this mode is used for RESET as initial default value regarding Set up menu which is in EEPROM(M24C02
)
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Set up menu Reset : OSD user Menu
à
user setting
à
restoration default value.
Ex.) Password…
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Vendor Logo screen : When Power on, the Logo screen which is in Flash-RAM goes to DRAM.
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Thus, if the initial logo screen is not been displayed, it because of DRAM line.
Regarding MP set
à
it may be caused from poor soldering.
7) Audio.
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Serial data(24bit/fs =48KHz) is transmitted to AK4393(DAC) at Sti5505.
l If set does not make any image on screen also audio data does not come out.
DATA Process:
Serial data +/-L/ R L / R double-mute
Sti5505
à AK4393 à CH mixing AMP à Gain AMP à Audio Out
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Mute : Double-mute at Out board. (Mute power <– ST/BY +5V).
8) Video.
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The data is taken care by SDRAM. Need 8M for NTSC & need 16M for PAL.
l Sti5505(Decoder – video signal:C-V, COMPOSITE, COMPONENT) à TSH95(Video 6dB gain AMP) à Output.
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TSH95 : handling ST/BY mute by switching bias at internal AMP.
è
check point : #8 and #9 Pin.
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If ST/By +5V,Mute power, is dropped , Mute will be on and it causes no signal on screen or only see black and
white screen intermittently.
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Mute on : 8(H) / 9(L). Mute off : 8(L) / 9(H)
à
High power should be over than 2.5V
l ST/BY +5V power is dead if Diode (1N4004) on Front board burn.
9) Digital output (Coaxial)
* High speed inventor
à
Pulse Trans(TS801: purpose impedance matching).
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DVD600