Wednesday, September 30, 2020

The Harman Kardon CD91 Circuit diagram, exploded view – Ultrawideband Linear Phase Cassette Deck

 Exploded views of CD mechanism, tape deck, full circuit diagram and wiring diagram.

Exploded view
Exploded view - tape deck
Full circuit diagram
Wiring diagram


Monday, September 21, 2020

TCL 14F7NX56CLA NX56AP and NX56B AP How to enter the service mode, adjustments, SMPS schematic

 

Version Information: Version states by two Arabic Numbers, which is separated by one dot, e.g. 1.2. The first number “1” means the version of approved file, the second one ”2” means the version of draft.

The way to enter P-Mode

Method one

A) Switch on the TV set.

B) Press the “MENU” key on RC to show the “PICTURE” OSD menu.

C) Move the cursor to “Contrast” item then press the “9”, “7”, “3”, “5” key continuously on RC within 3 seconds then enter P-Mode. The “P” letter will appear on the left low corner of the screen when enter P-Mode. Also the “FACTORY HOTKEY” will be set to “ON (= 1)”.

Another method

Press the “RECALL” key on RC to enter P-mode directly.

Note:

1. This will be active only when the “FACTORY HOTKEY” had set to “ON (= 1)”.

2. When the power on with “FACTORY HOTKEY” had set to “ON (= 1)”, the set will enter the P-Mode automatically.

Exit the P-Mode

Press the “RECALL” or “MENU” key on RC to exit the P-Mode.

Keys’ function on RC at the P-Mode

Use the RC to navigate in P-Mode:

Press “0” or “AT” key for screen voltage adjustment.

Press “1” to “8” and “FAV” key to select factory adjustment page.

Press “9” key to switch the I2C bus off/on.

Press “▲▼ or CH+ CH-key to select option.

Press “►◄ or VOL+ VOL- key to adjust or select option.

Press “DISPLAY” key to display software version.

Press “MENU” key to close the factory menu or return to the previous menu or exit the P-Mode.

Press “RECALL” key to enter or exit the P-Mode.

Note: All change in P-Mode will be saved in EEPROM automatically.

B+ Voltages

1. All relevant connectors and modules must be connected and inserted.

2. Main voltage is at 220VAC, 50Hz. voltage range:110VAC~240VAC,50Hz

3. Connect a voltmeter to B+ (Cathode of D808 for NX56 chassis or cathode of D833 for NX56B chassis) and switch on the set.

4. Input Philips test pattern signal and standard mode.

5. Adjust VR801, it should as the value in below form B+ Voltage.

RF AGC alignment

Method 1

A. Connect the detector as shown below (Picture 3.2) to collector of Q101.

B. Receive a grey scale signal with 70dBμV amplitude.

C. Enter P-Mode, press “6” key on RC to select “AGCT”.

D. Adjust AGCT item until the output of the detector becomes 0.8Vpp.

Method 2

A. Receive a grey scale signal with 60dBμV amplitude.

B. Enter P-Mode, press “6” key on RC to select “AGCT”.

C. Adjust the “AGCT” value until the hint display “AGC” just change between “0” and “1”.

Screen and Focus adjustment

Note: Alignment below should be done after 15 minutes warm up of TV.

1. Input cross hatch pattern signal to RF input.

2. Enter P-Mode.

2. Press “0” key on the RC and the screen will become a horizontal line.

3. Adjust the “SCREEN” VR of the FBT until the horizontal line can just be seen barely (minimum visible intensity).

4. Press “0” key again on the RC to exit the screen voltage adjustment mode.

5. Adjust the “FCOUS” VR of the FBT until the vertical line and horizontal line becomes Clear.

White Balance Adjustment

1. Input a black and white pattern to RF input.

2. Enter P-Mode, press key “3” to select white balance adjustment menu.

3. Use the color analyzer to measure the black side of the screen. Adjust the value of “RC”,”GC” and “BC” to set the reading of the color analyzer to x=274, y=280. (11500 K).

4. Then measure the white side of the screen. Adjust the value of “RD”, “GD” and “BD” to set the reading of the color analyzer to x=274, y=280. (11500 K).

5. Repeat step 3&4 until you can get the correct reading for both black and white sides.

Note:

A. The “SubBRI” and “SubCON” items are used to assistant the white balance adjustment.

It is the same function as the user OSD menu “Brightness” and “Contrast” items. You can adjust these items to get the expect intensity when adjusting the white balance.

B. The “BLOR-Y”, “BLOG-Y” and “BLOB-Y” items are used for the YUV white balance black level offset setup. When the TV white balance adjustment is done, connect a black and white pattern to YUV input terminal. Use the color analyzer to measure the black side of the screen. Adjust the value of the “BLOR-Y”, “BLOG-Y” and “BLOB-Y” to set the reading of the color analyzer to x=274, y=280.

Sub brightness adjustment

1. Input eight steps gray signal.

2. Press key “3” to enter sub-brightness adjustment.

3. At dynamic state, adjust “BRTC” until the secondary gray bar just to be seen.

Picture Geometry adjustment: Vertical geometry adjustment

1. Input a PAL crosshatch pattern signal to RF input.

2. Enter P-Mode, press key “1” to select vertical geometry adjustment. (The OSD menu for this adjustment as below table 3.6.1. For NTSC signal, the “-50” will be replaced with “-60”.)

3. Adjust the value of the corresponding item to make the vertical geometry of the pattern look good.

4. Apply NTSC signal to adjust these value for NTSC vertical geometry.

1. For NTSC signal, the “-50” will be replaced with “-60”.

2. For NTSC signal, only the “VCEN-60” and “VSIZE-60” items need the adjustment, the other items use the same data as PAL signal.

3. On producing, please use the “AUTO OFFSET” (On page “2”) function to easy the geometry adjustment of NTSC signal. When finished the PAL signal geometry adjustment, press “2” key to enter page “2” to select “AUTO OFFSET” item, press “” key to active the automatic offset function. Then the geometry adjustment of NTSC signal will finish automated. If the geometry of NTSC signal is look good, you don’t need to adjust the geometry of NTSC signal any more.

Horizontal geometry adjustment

1. Input a PAL crosshatch pattern signal to RF input.

2. Enter P-Mode, press key “2” to select horizontal geometry adjustment. (The OSD menu for this adjustment as below table 3.6.2. For NTSC signal, the “-50” will be replaced with “-60”.)

3. Adjust the value of the corresponding item to make the horizontal geometry of the pattern look good.

4. Apply NTSC signal to adjust these value for NTSC horizontal geometry.

Producing parameter setup and option

1. Enter P-Mode, press key “4” to select page “4”.Set the corresponding item to require value.

1). Set the shopping status

When trigger the “SHOP INIT” item form “0” to “1”, the TV will be put on selling status.

The TV status after shopping status:

“FACTORY HOTKEY” had set to “OFF”

B. Picture set to “Standard” status. (Brightness=50, Contrast=50, Colour=50, White tone=Normal.)

C. Sound set normal.(Volume=30,Balance=50.)

3). Set the value for “POWER LOW” and “POWER HIGH”

A. Connect the main voltage at low threshold 95VAC/50Hz.

B. Select item “POWER LOW”.

C. Adjust the value until the hint display just change between “AC: NORMAL” and “AC: LOW”.

D. Connect the main voltage at high threshold 255VAC/50Hz.

E. Select item “POWER HIGH.

F. Adjust the value until the hint display just change between “AC: NORMAL” and “AC: HIGH”.

2. Enter P-Mode, press key “5” to select page “5”. Set the corresponding item to require value. See below table for detailed description.

Description for AUTO OFFSET and GET OFFSET

The “GET OFFSET” can use to make the EEPROM copy by PE engineer. When the PAL and NTSC geometry adjustment had finished, trigger the “GET OFFSET” from “0” to “1” to store the geometry offset datum between PAL and NTSC in EEPROM.

On producing, these geometry offset datum can use to easy the NTSC geometry adjustment. When finished the PAL geometry adjustment, trigger the “AUTO OFFSET” from “0” to “1”, then the geometry adjustment of NTSC signal will finish automated. If now the geometry of NTSC signal is look good, it not needed to adjust the geometry of NTSC signal any more.

3. Enter P-Mode, press key “6” to select page “6”. Set the corresponding item to require value. See below table.

4. Enter P-Mode, press key “7” to select page “7”. Set the corresponding item to require value. See below table

Enter P-Mode, press key “8” to select page “8”. Set the corresponding item to require value. See below table


Note: When change the Language or the tuner type, you must AC restart the TV set to make it active

6. Enter P-Mode, press key “FAV” to select page “9”. Set the corresponding item to required value.

Screen voltage (VG2) adjustment with AKB function

1. Put the TV in AV source without input signal.

2. Enter P-Mode, press RC key "AT", there will display

3. Adjust the "SCREEN" VR of the FBT until VG2 hint display (LOW/OK/HIGH) display "OK" stably.

4. Press “MENU” return to P-Mode.

Printed circuit board Foil Side

SMPS schematic

Horizontal and Vertical output schematic

Video output schematic

Video IF and Chroma circuit


Monday, September 7, 2020

LGD FHD LGP37C-12HPC EAY62788701 SMPS board schematic, connector voltages, test method

 Power Supply Unit LGD : LGP37C-12HPC  AC 100V to AC 240V Used in 37 inch LGE LCD TV  Part code : LGD EAY62788701

80A zero-peak max.

At cold start and any specified line, load, and temperature Conditions.  The power supply efficiency should be more than 80% at the 90Vac maximum load condition, but it meet more than 85% excepted Inverter parts.  Power Factor over than 0.9 at 90 – 264Vac & max load condition.

On Condition: In a moment of Power-ON Signal activated, the current of 3.5V output should be limited within 40mA(Max) at LCD TV condition for stability.  [Do not turn “Power-ON” Signal on at the load condition of 3.5V output, more than 40mA.]

* Total regulation for each output circuit includes the results of input voltage variation, load variation, warm-up drift and temperature change.

* The following instruments shall be used for measuring ripple noise.

1. Probe having impedance ratio of 1:1.

2. Oscilloscope having frequency characteristic of 100MHz or more.

[Ripple and noise are measured at the end of output cable which are added a 0.1uF ceramic capacitor and 47uF electrolytic capacitor ( connected parallel ) . ( connected parallel )]


Burn-in

More than 30 minutes at 45(±5), Normal input voltage.

AC on/off must be test 1 time after burn-in.

80% Load of specification.

Protection

* This Power Supply has above-mentioned protections.

* Short circuit protection between different output terminals is not considered.

* Trip point for over voltage indicates the operating point when the output voltage slowly increases.

* The conditions of Over Current measurement

Multi output [3.5V, 12V, 24V] is normal load state except an over current measurement.

Sound Noise Characteristics.

PSU Noise Specification

22.5 dB(a) / 20.u Pa 2.0E-5 Pa

(1/1 octave, A-weighting, to 1khz ~ 16khz Total overall)

Measure Location: Anechoic Room

Measure Condition: At a distance of 60cm mike

Full white pattern, at AC 110V/220V

The max specification

(Measure 3 points, at PSU centre and left & right on the side)

Connectors Usage and voltages


Test methods

Intermittent Operation stability Test:  The switching regulator shall ON/OFF for 20,000 time at an Interval of 10 sec at maximum load, after that electrical Characteristics shall be satisfied.

Low temperature operation:  The switching regulator is left at the operating guarantee Minimum temperature for 2 hours without applying electricity.  After that that power shall be turned on, and then the electrical Characteristics shall be satisfied.

Low temperature Storage test Leave At low temperature:  The switching regulator is left at minimum storage Temperature for 96 hours or more.  Then the switching regulator is left at a room temperature and humidity for 1 hour or more, after that electrical characteristics shall be satisfied.

Heat cycle storage test: Then the switching regulator is left at a room temperature and humidity for 1 hour or more, after that electrical characteristics shall be satisfied.

Heat shock test: Heat shock test performed under following conditions without applying electricity and then leave them at room temperature and humidity for 1 hour or more.

After that, electrical characteristics shall be satisfied.

Condition: -45 (30minutes), 120(30minutes),

Switching time: Less than 5 minutes, 200 cycles.

Schematic Diagram


Block diagram