K15 PFCD 2602 TXT (GML2300)
TDA9351PS/N2 or TDA9381PS/N2 – TEA1507
(SMPS Control) – BSC25-N1641A (LOT) – 24MC08 (Memory)
MEMORY IC REPLACEMENT
This TV uses memory IC. In the
memory IC are memorized data for correctly operating the video and deflection
circuits.
PROCEDURE FOR REPLACING MEMORY IC
> Switch the power off and unplug the power cord from AC outlet.
> Be sure to use memory IC written with the initial data values.
> Plug the power cord into the AC outlet and switch the power on.
Check and set SYSTEM default value:
> Press “MENU” x3+1752 buttons in sequence to enter into factory status.
> If the memory IC haven’t been written with the initial data, press [P+] / [P-] to select item INIT and press [V+] / [V-] to start initialize memory IC.
> Check the setting value of the SYSTEM default value of Table below. If the value is different, select items by [P+] / [P-] keys and set value by [V+] / [V-] keys.
PROCEDURE FOR REPLACING MEMORY IC
> Switch the power off and unplug the power cord from AC outlet.
> Be sure to use memory IC written with the initial data values.
> Plug the power cord into the AC outlet and switch the power on.
Check and set SYSTEM default value:
> Press “MENU” x3+1752 buttons in sequence to enter into factory status.
> If the memory IC haven’t been written with the initial data, press [P+] / [P-] to select item INIT and press [V+] / [V-] to start initialize memory IC.
> Check the setting value of the SYSTEM default value of Table below. If the value is different, select items by [P+] / [P-] keys and set value by [V+] / [V-] keys.
> Press “TV/AV” button to return
to the normal screen.
SERVICE ADJUSTMENTS
Specific operation: use remote controller
Press “MENU” x3+1752” buttons in sequence to enter into factory mode.
Press [P+] / [P-] to select items and press [V+] / [V-] key, to make data adjustment of corresponding factory menus.
Press “AV/TV” key to exit factory mode.
Focus adjustment
> Receive a crosshatch signal.
> While watching the screen, adjust the FOCUS VR on the FBT to make the vertical and horizontal lines as fine and sharp as possible.
Geometrical adjustment
Receive PAL standard complete pattern signal.
Adjustment steps：
> Adjust VSL, to the centre horizontal line just appears from half bottom shadow.
> Adjust VAM, to get 92% of vertical picture contents would be displayed on CRT.
> Adjust VSH, the centre horizontal line corresponds to CRT vertical centre.
> Adjust SCL, to the linearity of P card field is in proper condition.
> Adjust HSH, to get the picture horizontal centre correspond to CRT horizontal centre.
Receive NTSC signal and repeat above adjustment.
Specific operation: use remote controller
Press “MENU” x3+1752” buttons in sequence to enter into factory mode.
Press [P+] / [P-] to select items and press [V+] / [V-] key, to make data adjustment of corresponding factory menus.
Press “AV/TV” key to exit factory mode.
Focus adjustment
> Receive a crosshatch signal.
> While watching the screen, adjust the FOCUS VR on the FBT to make the vertical and horizontal lines as fine and sharp as possible.
Geometrical adjustment
Receive PAL standard complete pattern signal.
Adjustment steps：
> Adjust VSL, to the centre horizontal line just appears from half bottom shadow.
> Adjust VAM, to get 92% of vertical picture contents would be displayed on CRT.
> Adjust VSH, the centre horizontal line corresponds to CRT vertical centre.
> Adjust SCL, to the linearity of P card field is in proper condition.
> Adjust HSH, to get the picture horizontal centre correspond to CRT horizontal centre.
Receive NTSC signal and repeat above adjustment.
AGC Adjustment
Receive 60dBμ (1mV) VH color bar pattern signal.
Select TOP item.
Adjust value, to noise reduce gradually and just disappeared point.
CRT cut off and white balance adjustment
a CRT cut off adjustment
> Select item VG2B, then adjust value to 32.
> PRESS “0” key, when the screen shows”VG2” adjust the SCREEN control on Fly back transformer to make the screen show alternating flashing characters of “INSIDE HIGH INSIDE LOW”.
b White balance adjustment
> Receive a Black and White pattern.> Adjust WRP, WRG, WRB items to get color temperature 9300K ±3 JND.
Receive 60dBμ (1mV) VH color bar pattern signal.
Select TOP item.
Adjust value, to noise reduce gradually and just disappeared point.
CRT cut off and white balance adjustment
a CRT cut off adjustment
> Select item VG2B, then adjust value to 32.
> PRESS “0” key, when the screen shows”VG2” adjust the SCREEN control on Fly back transformer to make the screen show alternating flashing characters of “INSIDE HIGH INSIDE LOW”.
b White balance adjustment
> Receive a Black and White pattern.> Adjust WRP, WRG, WRB items to get color temperature 9300K ±3 JND.
MAIN BOARD CIRCUIT DIAGRAM
TDA9351 PIN DETAILS
NICAM OPTION
STEREO OPTION
SMPS CIRCUIT DIAGRAM
DVD Part: Introduction of MTK1389D
maintenance
NOTE: MTK1389D is a type of LSIC for DVD decode .MTK1389D IC
consists of RF,SERVO,DSP,DECODE,VIDEO DAC and AUDIO DAC.
1. Under normal power supply conditions, the maintenance plan for MT1389D mono-chip is: first the reset circuit resets the MT1389D, after the crystal oscillator circuit gave the clock signal to MT1389D, MT1389D will start the initialization check for Flash E2PROM SDRAM, after everything is checked to be normal, it will start initialization check for built-in Audio DAC, servo and motor Driver IC .
2. If the all the a.m. parts are good, then MT1389D will send signal to motor Driver to drive the servo system pick up then to generate DVD light for collection, tracing the main shaft to check if there is any disc, and confirm if it is CD format or DVD format disc. If the disc is in DVD format, the system will read the data from the disc directly; if it is in CD format built-in servo will drive the CD laser to send out CD light and read the data, the data then will be amplified through built-in RF amplifier and sent to MT1389D decode part for data processing, released by MPEG and resolved into video data and audio data, then they will be returned to analog signals through built-in VIDEO DAC AUDIO DAC.
1. Under normal power supply conditions, the maintenance plan for MT1389D mono-chip is: first the reset circuit resets the MT1389D, after the crystal oscillator circuit gave the clock signal to MT1389D, MT1389D will start the initialization check for Flash E2PROM SDRAM, after everything is checked to be normal, it will start initialization check for built-in Audio DAC, servo and motor Driver IC .
2. If the all the a.m. parts are good, then MT1389D will send signal to motor Driver to drive the servo system pick up then to generate DVD light for collection, tracing the main shaft to check if there is any disc, and confirm if it is CD format or DVD format disc. If the disc is in DVD format, the system will read the data from the disc directly; if it is in CD format built-in servo will drive the CD laser to send out CD light and read the data, the data then will be amplified through built-in RF amplifier and sent to MT1389D decode part for data processing, released by MPEG and resolved into video data and audio data, then they will be returned to analog signals through built-in VIDEO DAC AUDIO DAC.
Decoder section
3. There is power supply, clock and reset, but the system does not work.
- Check if all the address wires required for FLASH are exist, and if they are in normal status, especially check if the A0~A15 of FLASH have normal signals, if there aren’t, then inspect MT1389D to see if there is faulty soldering. If there are normal signals at A0~A15, check if the address data signal of MT1389D and SDRAM is normal. If it is normal, then check the signal at A16~A19 of MT1389D; if there are also signals, then check the video output wires and AV filter circuit; if there is no signal, then check the corresponding pins of MT1389D to see if there is any short circuit, break or faulty soldering.
4. System in normal operation, but the audio has no sound.
- Because the AUDIO DAC is built in MTK1389D IC.you need to check the lower passing amplifying circuit and the MUTE circuit at the back of the LPF circuit. Also check if there is any power supply to the LPF circuit.
- Check if the power supply voltage required for playing is at normal level.
3. There is power supply, clock and reset, but the system does not work.
- Check if all the address wires required for FLASH are exist, and if they are in normal status, especially check if the A0~A15 of FLASH have normal signals, if there aren’t, then inspect MT1389D to see if there is faulty soldering. If there are normal signals at A0~A15, check if the address data signal of MT1389D and SDRAM is normal. If it is normal, then check the signal at A16~A19 of MT1389D; if there are also signals, then check the video output wires and AV filter circuit; if there is no signal, then check the corresponding pins of MT1389D to see if there is any short circuit, break or faulty soldering.
4. System in normal operation, but the audio has no sound.
- Because the AUDIO DAC is built in MTK1389D IC.you need to check the lower passing amplifying circuit and the MUTE circuit at the back of the LPF circuit. Also check if there is any power supply to the LPF circuit.
- Check if the power supply voltage required for playing is at normal level.
Servo Section
5. After the LOGO of the machine shows normally, there is no OSD display. This problem mainly is caused by the abnormality built-in RF and servo, possible problems may be:
- Built in RF and its surrounding circuits have problems.
- Servo part of MT1389D has problems.
6. OSD display is normal while there is no action of servo part feeding motor does not work, main shaft does no turn, possible fault status are:
- The corresponding signals giving by MT1389D to DMSO FMSO are missing, the reason may be the problem of MT1389D or the communication between MT1389D and motor Driver IC SA5668.
- Not output from Motor Driver, the reason may be the problem on motor Driver or its corresponding circuit.
7. Servo part in good status, while there is no pick up action no light, no focus
- No light, check the power supply power supply for pick up , or the light producing driving circuit to see if they are in normal status.
- No focus, check MT1389D to see if there is signal output from FOSO TRSO. Secondly, check motor driver to see if there is F+ F- T+ T-signal output.
Thirdly, check the external corresponding circuit of the motor driver to see if there is any problem.
8. All the servo part has action, while it cannot read out the disc
- Check MT1389D if there is RF net picture output, if there isn’t, then it must be the problem of MT1389D and external surrounding circuits, it there is output, then it might the problem of MT1389D and its surrounding circuits.
- There is RF signal but not in normal status then check MT1389D and surrounding circuits.
- Everything is normal, but the disc cannot be read out, check MT1389D and its surrounding circuit.
5. After the LOGO of the machine shows normally, there is no OSD display. This problem mainly is caused by the abnormality built-in RF and servo, possible problems may be:
- Built in RF and its surrounding circuits have problems.
- Servo part of MT1389D has problems.
6. OSD display is normal while there is no action of servo part feeding motor does not work, main shaft does no turn, possible fault status are:
- The corresponding signals giving by MT1389D to DMSO FMSO are missing, the reason may be the problem of MT1389D or the communication between MT1389D and motor Driver IC SA5668.
- Not output from Motor Driver, the reason may be the problem on motor Driver or its corresponding circuit.
7. Servo part in good status, while there is no pick up action no light, no focus
- No light, check the power supply power supply for pick up , or the light producing driving circuit to see if they are in normal status.
- No focus, check MT1389D to see if there is signal output from FOSO TRSO. Secondly, check motor driver to see if there is F+ F- T+ T-signal output.
Thirdly, check the external corresponding circuit of the motor driver to see if there is any problem.
8. All the servo part has action, while it cannot read out the disc
- Check MT1389D if there is RF net picture output, if there isn’t, then it must be the problem of MT1389D and external surrounding circuits, it there is output, then it might the problem of MT1389D and its surrounding circuits.
- There is RF signal but not in normal status then check MT1389D and surrounding circuits.
- Everything is normal, but the disc cannot be read out, check MT1389D and its surrounding circuit.
