Saturday, March 31, 2018

Magnavox. Emerson and Funai 32 inch LCD TVs – service mode, firmware update, power board schematics and power supply troubleshooting


Electrical adjustments are required after replacing circuit components and certain mechanical parts. It is important to perform these adjustments only after all repairs and replacements have been completed.
Do not attempt these adjustments unless the proper equipment is available
TYPE A
2ME303V/F7 MAGNAVOX (Serial No.: ME1, ME2)
LF320EM4 EMERSON (Serial No.: ME1, ME3)
LF320EM4F EMERSON (Serial No.: ME1, ME2)
LF320FX4F FUNAI (Serial No.: ME1)
TYPE B
LF320EM4 EMERSON (Serial No.: DS1)
LF320EM4F EMERSON (Serial No.: DS1)
LF320FX4F FUNAI (Serial No.: DS1, DS2)
How to set up the service mode
1. Turn the power on.
2. Press [MENU] button to display Setup menu.
3. Select “Features”.
4. Select “Software Upgrade”.
5. Select “Current Software Info”.
6. Press [0], [4], [2], [5], [7], [4] and [INFO] buttons on the remote control unit in this order.
The service mode screen appears.
Purity Check Mode
This mode cycles through full-screen displays of red, green, blue, and white to check for non-active pixels.
1. Enter the service mode.
2. Each time the [7] button on the remote control unit is pressed, the display changes.
To cancel or to exit from the Purity Check Mode, press [CH RETURN] or [PREV CH] button.
The VCOM Adjustment should be performed when replacing the Digital Main CBA for LF320EM4(Serial No.: DS1), LF320EM4F(Serial No.: DS1), and LF320FX4F(Serial No.: DS1, DS2).
1. Operate the unit for more than 60 minutes.
2. Set the color analyzer at the zero point calibration and bring the optical receptor pointing at the center of the LCD-Panel.
Note: The optical receptor must be set perpendicular to the LCD Panel surface.
3. Enter the service mode.
4. Press [2] button on the remote control unit.
5. Press [CHANNEL UP/DOWN] buttons on the remote control unit so that the color analyzer value becomes minimum.
6. To cancel or to exit from the VCOM Adjustment, press [CH RETURN] or [PREV CH] button.
White Balance Adjustment
The White Balance Adjustment should be performed when replacing the LCD Panel or Digital Main CBA.
Symptom of Misadjustment: White becomes bluish or reddish.
1. Operate the unit for more than 60 minutes.
2. Enter the service mode.
3. Press [VOLUME DOWN] button three times on the remote control unit to select “Drive setting” mode. “Drive” appears in the screen.
4. Set the color analyzer at the CHROMA mode and zero point calibration. Bring the optical receptor pointing at the center of the LCD-Panel.
[The optical receptor must be set perpendicularly to the LCD Panel surface.]
5. Press [3] button to select the “HDB” for High Drive Blue adjustment. (“HDB” appears in the screen.)
7. Press [CHANNEL UP/DOWN] buttons to adjust the color temperature becomes 12000°K (x= 0.272 / y= 0.278 ± 0.003).
8. Press [1] button to select the “HDR” for High Drive Red adjustment (“HDR” appears in the screen.) and press [CHANNEL UP/DOWN] buttons to adjust the color temperature.
9. If necessary, adjust the “HDB” or “HDR” again.
10. Press [6] button to select the “LDB” for Low Drive Blue adjustment (“LDB” appears in the screen.) and press [CHANNEL UP/DOWN] buttons to adjust the color temperature.
11. Press [4] button to select the “LDR” for Low Drive Red adjustment (“LDR” appears in the screen.) and press [CHANNEL UP/DOWN] buttons to adjust the color temperature.
12. If necessary, adjust the “LDB” or “LDR” again.
13. Press [VOLUME DOWN] button to shift to the “Debugging Message” mode.
If there is no message under “[WB]” section, this adjustment completes.
If “Drive settings are NG. Retry again.” Is displayed, repeat above steps from 5. to 12. Then check “Debugging Message” again. If “Drive settings are NG. Retry again.” is displayed, replace the LCD Panel or Digital Main CBA.
14. To cancel or to exit from the White Balance Adjustment, press [CH RETURN] or [PREV CH] button.
TO INITIALIZE THE LCD TV
The purpose of initialization is to place the set in a new out of box condition. The customer will be prompted to select a language and program channels after the set has been initialized.
To put the program back at the factory-default, initialize the LCD TV using the following procedure.
[Disconnect any device from the USB Port before you conduct on this procedure.]
1. Turn the power on.
2. Enter the service mode.
- To cancel the service mode, press [Power] button on the remote control unit.
3. Press [BACK] button to enter the Control Panel Key Confirmation Menu.
4. Press any button on the control panel.
5. Press [INFO] button to proceed with the self check mode.
6. Make sure to confirm the “INITIALIZED FINISH” appears in the green screen.
7. Unplug the AC Cord and plug it back on again.
SMPS SCHEMATIC
There are two types of power board fitted with these TVs.
Fixed voltage (or Auto voltage selectable) power supply circuit is used in this unit.If Main Fuse (F602) is blown , check to see that all components in the power supply circuit are not defective before you connect the AC plug to the AC power supply.
Otherwise it may cause some components in the power supply circuit to fail.
For continued protection against risk of fire, replace only with same type 2.5A, 250V fuse.
The voltage for parts in hot circuit is measured using hot GND as a common terminal.
Type 1 PWB and Schematic


Type 2 PWB and schematic
Click on the pictures to zoom in
Power board Troubleshooting
* The power cannot be turned on.
Is the fuse (F602) normal? – No > 
The fuse blows out.
Is normal state restored when once unplugged power cord is plugged again after several seconds? – NO
✓ Check if there is any leak or short-circuit on the primary circuit component and repair it if defective. Check these components.
(C607, D601, D602, D603, D604, D605, D607A, D608, D609A, D621, D623, Q601, Q602, Q621, R611, T601)
If yes:
Is the P-ON+21V line voltage normal?
If yes
✓Check each rectifying circuit of the secondary circuit and repair it if defective. Check for any short circuited components.
If NO:
✓Check if there is any leak or short-circuit on the primary circuit component and repair or replace the defective component/s. Check:
(C607, D601, D602, D603, D604, D605, D607A, D608, D609A, D621, D623, Q601, Q602, Q621, R611, T601)
The fuse blows out
✓ Check if there is any leak or short-circuit on the primary circuit component and repair it if defective.
✓Check if there is any leak or short-circuit on the each rectifying circuit component of secondary side and repair/replace it if found defective.
 [NB]: Make sure to repair the primary circuit component before replacing the fuse (F602).
The output voltage fluctuates.
Does the photocoupler circuit on the secondary side operate normally?
NO?
✓Check IC602, D660, D661, Q653 and their periphery circuit. Repair it if defective.
If yes:
✓Check IC602, D605, D607A, D608, D609A, D610, D621, D623, Q601, Q602, Q621 and their periphery circuit.
Repair/ replace the defective component/s.
When buzz sound is heard in the periphery of power circuit.
✓Check if there is any short-circuit on the rectifying diode and the circuit in each rectifying circuit of the secondary side.
Repair it if defective. (D650, D651, D653, D655, Q656, Q658) [ A slight loose fitting of the ferrite core of any converter transformers too will make a buzzing sound. Check for it too]
P-ON+21V is not output.
Is approximately +21V voltage supplied to the cathode of D650(D651)?
NO?
✓Check D650, D651, C651, C652, C653 and their periphery circuit. Repair it if defective.
If yes:
✓Check if there is any leak or short-circuit on the load circuit. Repair it if defective.
AMP+13V is not output.
Is approximately +13V voltage supplied to the cathode of D653(D655)?
NO?
✓Check D653, D654, D655, C654, C655 and their periphery circuit. Repair it if defective.
If yes:
✓Check if there is any leak or short-circuit on the load circuit. Repair it if defective.
AL+3.3V is not output.
Is approximately +13V voltage supplied to the collector of Q656?
NO?
Is approximately +13V voltage supplied to the emitter of Q658?  If yes: Replace Q658
If NO: 
✓Check D653, D654, D655, C654, C655, R690 and their periphery circuit. Repair it if defective.
Approximately +13V voltage is at  the collector of Q656
Is approximately +4V voltage supplied to the base of Q656? NO? Check D662 and their periphery circuit. Repair it if defective.
If yes:
Replace Q656.
Firmware Update Procedure
User Upgrade (Filename example: TVNB012_00_UF_XX91_AC.ecc)
Upgrade the firmware only. The setting values will not be initialized.
The User Upgrade and the Firmware Upgrade (Factory Upgrade) will be done by the same file. If you want to upgrade the firmware and initialize the setting values also, add “FACT_” at the beginning of the filename.
If you want to upgrade the firmware only and leave the setting values as they are, eliminate the “FACT_” from the filename.
Update procedure
1. Turn the power on.
2. Press [MENU] button to display Menu.
3. Select “Features”.
4. Select “Software Upgrade”.
5. Select “Upgrade” to display Upgrade screen.
6. Press [OK] button to display Software Upgrade screen.
7. Select “USB” and press [OK] button.
8. Insert the USB storage device to the USB port
9. Select “Check” and press [OK] button.
10. Select “Upgrade” and press [OK] button to start software upgrade.
11. The update will start and the upgrade screen will appear.
[If the screen isn’t displayed, repeat from step 1.]
12. When the firmware update is completed, the following will appear in the screen.
Remove the USB storage device from the USB port.
Turn the power off and turn the power on again.
Factory Upgrade (Firmware Upgrade/Flash Upgrade)
Firmware Upgrade(Filenam
e example: FACT_TVNB012_00_UF_XX91_AC.ecc)
Upgrade the firmware and initialize the setting values.
The User Upgrade and the Firmware Upgrade (Factory Upgrade) will be done by the same file. If you want to upgrade the firmware and initialize the setting values also, add “FACT_” at the beginning of the filename.
If you want to upgrade the firmware only and leave the setting values as they are, eliminate the “FACT_” from the filename.
Flash Upgrade
(Filename example: ALL_TVNB012_00_UF_XX91_AC.ecc)
Upgrade the firmware and initialize the setting values along with the factory default such as White Balance, etc.
Before the upgrade, you will need to make a note of all the factory default so you will be able to set it back on the TV after the initialization.
The Flash Upgrade will be done by it's unique file.
The User Upgrade/Firmware Upgrade (Factory Upgrade) file cannot be used for this upgrade.
Procedure
1. Turn the power off.
2. Insert the USB storage device to the USB port.
3. Turn the power on.
4. The update will start and the upgrade screen will appear.
5. When the firmware update is completed, the relevant screen will appear in the screen.
Remove the USB storage device from the USB port.
Turn the power off and turn the power on again.
Service mode initial screen with a word “INITIALIZED” will appear in the screen. The color of the word “INITIALIZED” will change from red to green when initialization is completed.