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POWER SMPS AND HORIZONTAL OUTPUT SCHEMATIC - TOSHIBA 29CJZ8UR - STRX6769 (Power Switching) – PS258 (Optocoupler-voltage control) – TBF4216AS [FBT]
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INFINITY REF610A POWER AMPLIFIER – CAR AUDIO – WIRING DIAGRAM - TROUBLESHOOTING
CLICK ON DIAGRAM TO ZOOM
TROUBLESHOOTING
PROBLEM:
No audio (POWER LED is off).
CAUSE and SOLUTION:
No voltage at BATT+ and/or REM terminals, or bad or no ground connection. Check voltages at amplifier terminals with VOM.
PROBLEM:
No audio (PROTECT LED flashes every 4 seconds).
CAUSE and SOLUTION:
DC voltage on amplifier output. Amplifier may need service; see enclosed warranty card for service information.
PROBLEM:
No audio (PROTECT LED is on).
CAUSE and SOLUTION:
Amplifier is overheated. Make sure amplifier cooling is not blocked at mounting location; verify that speaker-system impedance is within
specified limits.
PROBLEM:
No audio (PROTECT and POWER LEDs flash).
CAUSE and SOLUTION:
Voltage less than 9V on BATT+ connection. Check vehicle charging system.
PROBLEM:
No audio (PROTECT LED is on).
CAUSE and SOLUTION:
Voltage greater than 16V or less than 8.5V on BATT+ connection. Check vehicle-charging system.
PROBLEM:
Distorted audio.
CAUSE and SOLUTION:
Input sensitivity is not set properly, or amplifier or source unit is defective. Check INPUT LEVEL setting, or check speaker wires for shorts or
grounds.
PROBLEM:
Distorted audio (PROTECT LED flashes).
CAUSE and SOLUTION:
Short circuit in speaker or wire. Remove speaker leads one at a time to locate shorted speaker or wire, then repair.
PROBLEM:
Music lacks “punch.”
CAUSE and SOLUTION:
Speakers are not connected properly. Check speaker connections for proper polarity.
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HITACHI CPDW10 - PROJECTOR - HOW TO REPLACE LAMP - RESET LAMP TIME
A lamp has finite product life. Using the lamp for long periods of time could cause the pictures darker or the color tone poor. Note that each lamp has a different lifetime, and some may burst or burn out soon after you start using them. Preparation of a new lamp and early replacement are recommended.
- Turn the projector off, and unplug the power cord. Allow the projector to cool for at least 45 minutes.
- Prepare a new lamp.
- Loosen the screw (marked by arrow) of the lamp cover and then slide and lift the lamp cover to the side to remove it.
- Loosen the 2 screws (marked by arrow) of the lamp, and slowly pick up the lamp by the handles. Never loosen any other screws.
- Insert the new lamp, and re-tighten firmly the 2 screws of the lamp that are loosened in the previous process to lock it in place.
- While putting the interlocking parts of the lamp cover and the projector together, slide the lamp cover back in place. Then firmly fasten the screw of the lamp cover.
Turn the projector on and reset the lamp time using the LAMP TIME item in the OPTION menu.
- Press the MENU button to display a menu.
- Point at the ADVANCED MENU in the menu using the ▲/▼ cursor buttons, then press the ►cursor (or the ENTER button).
- Point at the OPTION in the left column of the menu using the ▲/▼ cursor buttons, then press the ►cursor (or the ENTER) button.
- Point at the LAMP TIME using the ▲/▼cursor buttons, then press the ► cursor (or the ENTER/ the RESET) button. A dialog will appear.
Click on picture to ZOOM
Reset the lamp time only when you have replaced the lamp, for a suitable indication about the lamp.
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HOW TO ENTER SERVICE MENU - Reset Network Web Password - HITACHI CPDW10N [A2DWXN] - PROJECTOR
To display OSD for hidden Service Menu
By the control panel.
- Display the Advanced menu by the “MENU” button.(If EASY MENU appears, choose “Go to Advanced menu” to display ADVANCED MENU.)
- Select the “OPTION” on the menu.
- Continue press the button [◄ ] first, then press the button [◄ ] together with “INPUT”, and hold for 3 seconds.
- Display the menu by the “MENU” button. (If EASY MENU appears, choose “Go to Advanced menu” to display ADVANCED MENU.)
- Select the “OPTION” on the menu.
- Press the “MAGNIFY OFF” button. Next hold the “MAGNIFY OFF” button for 3 seconds.
START-UP TYPE
Select the startup screen type.
- Shows Hitachi Logo
- No Hitachi Logo
Use time of LCD panel. Reset the PANEL TIME whenever you changed the LCD/LENS prism assembly panel.
LONG KEY
You can select the remote control button operation mode. NORMALß>LONG. The LONG allows to control the projector with the remote control unit when you hold a button of it for about 3seconds, and makes MY BUTTON 1/2 function as LONG KEY DISABLE/LONG KEY ENABLE compulsorily. If you use these buttons to control the projector as you assigned with the MY BUTTON menu, set to the NORMALNETWORK RESET
If this is executed, all of the network settings are initialized.SOFT RESET
If this is executed, all of the user data is initialized. Never use it when not required.
Reset of the Network Web password / User ID, Network Control password
ATTENTION: Performing this operation initializes the network settings. If the projector has the customized settings in the network, make a note of the network settings to restore them before this operation.
- Display the SETUP in the NETWORK menu.
- Select “TURN OFF” in the item of DHCP.
- Enter “255.255.255.255” in the item of IP ADDRESS.
- Enter “255.255.255.255” in the item of SUBNET MASK.
- Enter “255.255.255.255” in the item of DEFAULT GATEWAY.
Click on pictures to ZOOM
- While NETWORK menu is displayed, press the RESET button of the remote control.
- Press ▲button to execute reset. The operation described above resets not only Web password but also NETWORK settings.
When you execute this reset operation with any other settings than above (described in the step 2 to 5), the WEB password, SNTP server address, DATE AND TIME and other schedule settings are not initialized, but the network settings (DHCP, IP ADDRESS, SUBNET MASK and DEFAULT GATEWAY) are initialized.
- If the network settings had been customized, restore them by manual operation.
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How to Deactivate Security Functions – Pin Lock System - HITACHI CP DW10N A2DWXN Projector
MyScreen PASSWORD
The MyScreen PASSWORD function can be used to prohibit access to the MyScreen function and prevent the currently registered MyScreen image from being overwritten.
PIN LOCK
PIN LOCK is a function, which prevents the projector from being used unless a registered Code is input.
Transition detector
Transition detector is a function which prevents the projector from being used if vertical angle of the projector and mirror setting is not same with recorded.MY TEXT
This item allows you to display your own message (MY TEXT) on the START UP screen and INPUT INFORMATION. It can be protected by a password to prevent it from being overwritten.
It is possible to deactivate all security functions temporarily with following procedures.
- Go to "ENTER PASSWORD" on SECURITY menu and press the ► button.
- Then, ENTER PASSWORD box will be displayed. (The BOX will be displayed by pressing the [MENU] button (remote) or [▲/▼/◄/►] button (keypad) when Transition Detector Alarm is displayed.)
- Press the [Magnify off] button once, then press [Magnify off] button of remote for 3 second or more to display SERVICE PASSWORD box.
- Enter the Life Key (MENU, ▼, KEYSTONE, ▲). Then all security functions will be deactivated temporarily.
- The Life key can be used up to 30 times. The key cannot be used thereafter. If the Life key cannot be used, see the paragraph of SECURITY in the User’s Manual.
- The frequency in which Life key is input will be set to 0 after the registered code is input.
- The SECURITY Menu can not be operated if the SECURITY PASSWORD was released by Life key.
- The Mirror, Keystone and Auto keystone are not memorized though they are possible to operate if Transition Detector was released by Life key.
- The MyScreen Lock on SCREEN Menu keeps “TURN ON” if MyScreen PASSWORD was set when SECURITY PASSWORD was released by Life key.
PIN LOCK SYSTEM
If the following PIN BOX menu appears after power on the projector, the PIN LOCK system has been activated. Under such a condition, key operations and signal displaying are inhibited. To open the PIN LOCK system, we need to input the correct 4 digits PIN CODE. If correct PIN CODE is not input in 5 min., the lamp will be automatically turned off.
Returning repaired unit
- Use the Master PIN code. See the paragraph of releasing the PIN LOCK system deactivation.
- Release all security systems. See the paragraph of the PIN LOCK system deactivation.
- When the PIN BOX menu is displayed, sequentially enter the codes with remote controller as follows. In accordance with remote controller button entry, “*” mark appears in the PIN BOX menu. Master PIN codes
2nd entry code: Press the ▼button.
3rd entry code: Press the “KEYSTONE” button.
4th entry code: Press the ▲ button.
- Note: The Master PIN codes can be used up to 30 times. The codes cannot be used thereafter. If the Master PIN codes cannot be used, see the paragraph of the PIN LOCK system deactivation.
- When the PIN BOX menu is displayed, press “RESET” for 3 seconds or more in order to get the ID Inquiring Code.
- Send HITACHI sales company the Inquiring code (10 digits) to inquire the correct PIN code.
- With the PIN BOX menu displayed, input the correct PIN code. Enter the correct PIN CODE that HITACHI sales company informed.
- Open menu and select “TURN OFF”from the PIN LOCK items in the SECURITY menu. Then the PIN BOX menu appears. Password is required to display the Security Menu.
- Input the correct PIN code in the PIN BOX menu.
- Then, PIN LOCK will be set to “TURN OFF”.
- Deactivate the MyScreen PASSWORD, Transition Detector and My Text PASSWORD as well.
- Reset the Security Password to the [3410].
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TV POWER SUPPLY [SMPS] SCHEMATIC - HS817 [Opto coupler Voltage Control] – STR G5653 / STR G6454R [Power switching Output]
Switch-mode Power Supply STR- G5653/F6654
The Series STR-G5653/F6654 is specifically designed to satisfy the requirements for increased integration and reliability in off-line quasi-resonant fly back converters. The series incorporates a high-precise error amplifying control and drive circuit with discrete avalanche-rated power MOSFET, featuring fewer external components, small-size and standard power supply. Covering the power range from below 25 watts up to 300 watts for 100/115/230 VAC inputs, and up to 150 watts for 85 to 265 VAC universal input, these devices can be used in a range of applications, from battery chargers and set top boxes, to televisions, monitors, and industrial power supply units. Cycle-by-cycle current limiting, under-voltage lockout with hysteresis, over-voltage protection, and thermal shutdown protects the power supply during the normal overload and fault conditions. Low-current startup and a low-power standby mode selected from the secondary circuit completes a comprehensive suite of features. The series is provided in a five-pin over molded SIP style package, affording dielectric isolation without compromising thermal characteristics.- Flyback Operation with Quasi-Resonant Soft Switching for Low Power Dissipation and EMI
- Rugged Avalanche-Rated MOSFET
- Soft drive circuit MOSFET
- Adjustable MOSFET switching speed
- Choice of MOSFET Voltage and rDS(on)
- Full Over-Current Protection (no blanking)
- Under-Voltage Lockout with Hysteresis
- Over-Voltage Protection
- Direct Voltage Feedback
- Low Start-up Current (100μAmax)
- Low-Frequency, Low-Power Standby Operation
- Over molded 5-Pin Package
INTERNAL CIRCUIT OF IC
PCB PART - PRINT SIDE
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LG 37LD420/420N – LG 37LD428/420C - MAIN PCB CHECK PROCESS - USB DOWNLOAD - ADJUSTMENTS
APC - After Manual-Insult, executing APC
- Execute ISP program “Mstar ISP Utility” and then click “Config” tab.
- Set as below, and then click “Auto Detect” and check “OK” message. If “Error” is displayed, Check connection between computer, jig, and set.
- Click “Read” tab, and then load download file (XXXX.bin) by clicking “Read”
- Click “Connect” tab. If “Can’t” is displayed, check connection between computer, jig, and set.
- Click “Auto” tab and set as below
- Click “Run”.
- After downloading, check “OK” message.
USB DOWNLOAD
- Put the USB Stick to the USB socket
- Automatically detecting update file in USB Stick. If your downloaded program version in USB Stick is Low, it didn’t work. But your downloaded version is High, USB data is automatically detecting.
- Show the message “Copying files from memory”
- Update starting.
- Uploading completed, The TV will restart automatically.
- If your TV is turned on, check your updated version and Tool option.(explain the Tool option, next stage) * If downloading version is more high than your TV have, TV can lost all channel data. In this case, you have to channel recover. if all channel data is cleared, you didn’t have a DTV/ATV test on production line.
- Push "IN-START" key in service remote controller
- Select “Tool Option 1” and Push “OK” button.
- Punch in the number. (Each model hex their number)
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HOW TO DO ADC CALIBRATION AND FUNCTION CHECK - LG 37LD420 Z LCD TV
- Enter Service Mode by pushing “ADJ” key,
- Enter Internal ADC mode by pushing “G” key at “5. ADC Calibration”
ADC Calibration Protocol (RS232)
Adjust Sequence
aa 00 00 [Enter Adjust Mode]
xb 00 40 [Component1 Input (480i)]
ad 00 10 [Adjust 480i Comp1]
xb 00 60 [RGB Input (1024*768)]
ad 00 10 [Adjust 1024*768 RGB]
aa 00 90 End Adjust mode
Required equipment : Adjustment R/C.
FUNCTION CHECK
Check display and sound, Check Input and Signal items. (cf. work instructions)
- TV
- AV (SCART1/SCART2/ CVBS)
- COMPONENT (480i)
- RGB (PC : 1024 x 768 @ 60hz)
- HDMI
- PC Audio In
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PHILIPS 21PD5932/78 - TV-DVD COMO - MAIN POWER [SMPS] SCHEMATIC [Circuit Diagram] [Click on Schematic to Zoom] - TEA1523 [Power Control IC]
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HOW TO ENTER, ADJUST AND EXIT SERVICE MODE TO PHILIPS 20DV693 CTV
TO ENTER SERVICE MODE
- Use a standard customer RC-transmitter and key in the code ‘062596’ directly followed by the OSD / STATUS button.
- The following screen is visible, with SAM at the upper right side for recognition. [SAM = Service Alignment Mode]
- LLLL This is the operation hours counter. It counts the normal operation hours, not the standby hours.
- AAABCD-X.Y This is the software identification of the main micro controller:
B = the region: E= Europe, A= Asia Pacific, U=
NAFTA, L= LATAM.
- C = the software diversity: C= NTSC, D= DVD, N= no TXT, T= TXT.
X = the main software version number.
Y = the sub software version number.
- SAM Indication of the actual mode.
- Error buffer Five errors possible.
- Option bytes Seven codes possible.
- Clear Erase the contents of the error buffer. Select the CLEAR menu item and press the CURSOR RIGHT key. The content of the error buffer is cleared.
- Options To set the Option Bytes.
- AKB Disable (0) or enable (1) the ‘black current loop’ (AKB = Auto Kine Bias).
- Tuner To align the Tuner. See chapter 8.3.2 for a detailed description.
- White Tone To align the White Tone.
- Geometry To align the Geometry.
- Audio To align the Audio.
TO NAVIGATE
- In SAM, select menu items with the CURSOR UP/DOWN key on the remote control transmitter. The selected item will be highlighted. When not all menu items fit on the screen, move the CURSOR UP/DOWN key to display the next / previous menu items.
- With the CURSOR LEFT/RIGHT keys, it is possible to:
Change the value of the selected menu item.
Activate the selected sub-menu.
- When you press the MENU button twice, the set will switch to the normal user menus (with the SAM mode still active in the background). To return to the SAM menu press the OSD / STATUS button [ i+ ].
- When you press the MENU key in a sub-menu, you will return to the previous menu.
TO EXIT SERVICE MODE
Switch the set to STANDBY by pressing the power button on the remote control (if you switch the set 'off' by removing the AC power, the set will return in SAM when AC power is reapplied). The error buffer is not cleared.↧
BLINKING CODES - ERROR CODES - FAULT SYMPTOMS - PHILIPS 20DV693 (DV Series TVs)
Via this procedure, you can make the contents of the error buffer visible via the front LED. This is especially useful when there is no picture.
When the SDM is entered, the LED will blink the contents of the error-buffer.
Error-codes greater than or equal to 10 are shown as follows:
- a long blink of 750 ms (which is an indication of the decimal digit),
- a pause of 1.5 s,
- n short blinks (n = 1 - 9),
- when all the error-codes are displayed, the sequence; finishes with a LED blink of 3 s,
- the sequence starts again.
After entering SDM:
1 long blink of 750 ms followed by a pause of 1.5 s,
2 short blinks followed by a pause of 3 s,
9 short blinks followed by a pause of 3 s,
6 short blinks followed by a pause of 3 s,
1 long blink of 3 s to finish the sequence,
the sequence starts again.How to Clear the Error Buffer
The error code buffer is cleared in the following cases:
By activation of the CLEAR command in the SAM menu:
- When you exit SDM / SAM with the STANDBY command on the remote control (when leaving SDM / SAM, by disconnecting the set from AC power, the error buffer is not reset).
- When you transmit the command DIAGNOSE-99-OK with ComPair.
- If the content of the error buffer has not changed for 50 hours, it resets automatically.
In case of non-intermittent faults, clear the error buffer before you begin the repair. These to ensure that old error codes are no longer present. If possible, check the entire contents of the error buffer. In some situations, an error code is only the result of another error code and not the actual cause (e.g., a fault in the protection detection circuitry can also lead to a protection).
The error code buffer contains all detected errors since the last time the buffer was erased. The buffer is written from left to right. When an error occurs that is not yet in the error code buffer, it is written at the left side and all other errors shift one position to the right.
Error | Device | Error description | Def. Item |
0 | Not applicable | No error | |
1 | Not applicable | x-ray overvoltage protection [USA only] | 2465, 7460 |
2 | Not applicable TDA8359/TDA9302 | Horizontal protection Vertical protection | 7460, 7461, 7462, 7463, 7467 7861,vlot aux +13V |
3 | Reserve | ||
4 | MSP34X5/TDA9853 | MSP I2C identification error | 7831/7861 |
5 | TDA95XX | POR 3v3/+8V protection | 7200,7560,7480 |
6 | I2C bus | General I2C bus error | 7200, 3624, 3625 |
7 | AN7522/3 | Power down [over current] protection | 7901, 7902, 7561 |
8 | Not applicable | E/W protection (large screen) | 7400,3405,3406,3400 |
9 | M24C08 | NVM I2C identification error. | 7602, 3611,3603/04 |
10 | Tuner | Tuner I2C identification error | 7482,1000 |
11 | TDA6107/8 | Back current loop protection | 7330 RGB amps, CRT. |
12 | M65669 | PIP I2C identification error | 7803 |
If a fault situation is detected an error code will be generated and if necessary, the set will be put in the protection mode. Blinking of the red LED at a frequency of 3 Hz indicates the protection mode. In some error cases, the microprocessor does not put the set in the protection mode. The error codes of the error buffer can be read via the service menu (SAM), the blinking LED procedure or via ComPair. The DST diagnose functionality will force the set into the Service standby, which is similar to the usual standby mode, however the microprocessor has to remain in normal operation completely.
REPAIR TIPS
- Set is dead and makes hiccupping sound‘ MainSupply’ is available. Hiccupping stops when de-soldering L5561, meaning that problem is in the ‘Main Supply’ line. No output voltages at LOT, no horizontal deflection. Reason: line transistor TS7460 is defective.
- Set is dead, and makes no sound Check power supply IC7520. Result: voltage at pins 1, 3, 4, 5 and 6 are about 180 V and pin 8 is 0 V. The reason why the voltage on these pins is so high is because the output driver (pin 6) has an open load. That is why MOSFET TS7521 is not able to switch. Reason: feedback resistor 3523 is defective.
- Set is in hiccup mode and shuts down after 8 s. Blinking LED (set in SDM mode) indicates error 5. As it is unlikely that uP ‘POR’ and ‘+8V protection’ happen at the same time, measure the ‘+8V’. If this voltage is missing, check transistor TS7480.
- Set is non-stop in hiccup mode Set is in over current mode; check the secondary sensing (opto coupler 7515) and the ‘Main Supply’ voltage. Signal ‘Stdby_con’ must be logic low under normal operation conditions and goes to high (3.3 V) under standby and fault conditions.
- Set turns on, but without picture and sound The screen shows snow, but OSD and other menus are okay. Blinking LED procedure indicates error 11, so problem is expected in the tuner (pos. 1000). Check presence of supply voltages. As ‘Vlotaux+5V’ at pin 5 and 7 are okay, ‘VT_supply’ at pin 9 is missing. Conclusion: resistor 3460 is defective.
- Set turns on, but with a half screen at the bottom. Sound is okay Blinking LED (set in SDM mode) indicates error 3. Check ‘Vlotaux+13V’ and ‘+50V’. If they are okay, problem is expected in the vertical amplifier IC7471. Measure with a scope the waveform on pin 17 of the UOC. Measure also at pin 1 of IC7471. If here the signal is missing, a defective resistor R3244 causes the problem.
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SHARP AM400 DIGITAL COPIER PRINTER - POWER SUPPLY - [SMPS]-SCHEMATIC (Circuit Diagram)
{CLICK ON PICTURES TO ZOOM}
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AM 300DE - AM 400 - SHARP DIGITAL COPIER PRINTER - HIGH-VOLTAGE PWB SCHEMATIC [Circuit Diagram]
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PWB - FOIL SIDE
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SHARP AM 300DE - COPIER PRINTER - MECHANICAL OPERATIONS
The planet gear A moves toward the scan unit drive side gear and stops at the intermediate position because the pin A on the planet gear. A mounting arm is restricted its movement by the cam groove A. The planet gear B moves into engagement with the system gear so that the system gear rotates. Along with the rotation of the system gear, the scan unit locking lever starts rotating in the release direction.
Switching operation from the sheet scan mode to the fixed scan mode (2).
Rotation of the system gear releases the pin A on the planet gear A mounting arm from the cam groove A, and the planetary gear A is engaged with the scan unit drive side gear. The scan unit starts moving toward the fixed scan side.
Switching operation (3) from the sheet scan mode to the fixed scan mode.
Due to the system gear rotation, the pin B is guided in the cam groove B to turn the planet gear B mounting arm. The planet gear B is disengaged from the system gear, and the system gear loses its power.
Switching operation (4) from the sheet scan mode to the fixed scan mode.
The system gear is driven by the system gear biasing spring until it reaches the stopper at the release position of the scan unit locking lever.
{Click on Pictures to Zoom}
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SHARP - AM 300DE - MECHANISM - DESCRIPTIONS - and Working
When the scan unit's lever that comes back to the sheet scan position pushes the system gear pin, the system gear starts rotating in clockwise direction.
Due to the system gear rotation, the pin B on the planet gear mounting arm is guided in the cam groove B, and the planet gear B is engaged with the system gear. Along with the system gear rotation, the scan unit locking lever moves toward the lock position.
Rotation of the system gear releases the pin A on the planet gear A mounting arm from the cam groove A. The planet gear A moves to the intermediate position between the scan unit drive side gear and the sheet scan drive side gear. At this time, the belt stops moving, and the scan unit stops accordingly just before the sheet scan position.
Click on pictures to zoom
Rotation of the system gear releases the pin B on the planet gear B mounting arm from the cam groove B, and the planet gear B is disengaged from the system gear. After the disengagement, the system gear is kept rotating in clockwise direction by the system gear biasing spring. The scan unit locking lever is moved by the system gear, and it stops after pushing the scan unit to the locking rib. Keep rotating the motor in the counter-clockwise direction for the sheet feeding operation.
Image forming operation details by next post:
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COPIER PRINTER - SHARP AM 400 - SHARP AM300DE Laser Scaner Printer - Image Forming Operation
The main charger is a rotating brush roller. The main charger removes residual toner from the OPC drum by its rotating sweeping action and causes it to stick to the brush. At the same time, a high voltage of -950V is applied to the main charger roller to generate a discharge of electricity between the roller and the OPC drum, generating positive and negative charges. The negative charges are attracted to the OPC drum, and evenly distributed on the OPC drum. (The OPC drum surface is evenly charged.)
Laser beam scanning light corresponding to the print data is radiated on the OPC drum. Positive and negative charges are generated in the OPC drum CGL exposed with the laser beam. Positive charges generated in the CGL are attracted toward the OPC drum surface (negative charges), and negative charges toward the aluminium layer (positive charges). Therefore, the positive and negative charges neutralize each other in the laser-exposed area of the OPC drum surface and the aluminium layer, decreasing the potential of the OPC drum surface. The area, which is not exposed to laser beam, has no change, and the OPC drum surface remains negatively charged to keep a high potential. As a result, latent electrostatic images are formed on the OPC drum.
CLICK ON PICTURES TO ZOOM
Development
Toner is attached to the latent electrostatic images on the OPC drum to form visible images. Toner is transported to the scraper area by the toner supply roller and the developing roller. The scraper controls the quantity of toner to be transported to the doctor section. Toner transported to the doctor section is then passed between the developing roller and the doctor to form a thin toner layer on the developing roller by the pressure applied by the doctor. When toner passes between the developing roller and the doctor, it is charged negatively by friction. When an area of OPC drum, which was exposed, to laser beam and lost its charge comes in contact with the developing roller, toner moves from the developing roller to the OPC drum surface. The principle of toner movement from the developing roller to the OPC drum surface is as follows.
The bias voltage of DC-280V is applied to the developing roller. Toner is charged negatively by the difference (electrical energy) between the bias voltage and the OPC drum surface potential and is attracted to the OPC drum surface which is positively charged. At that time, the potential of the area of the OPC drum, which was exposed to the laser beam and lost its charge, is higher than that of the developing roller.
On the other hand, when an area of OPC drum, which was not exposed to the laser beam and did not lose its charge comes in contact with the developing roller, any residual toner attached to the OPC drum is transferred to the developing roller which is more positively charged. As a result, the developing unit collects unnecessary toner on the OPC drum. The operating principle for that case is contrary to that for transfer of toner from the developing roller to the OPC drum surface. (The electric field energy direction is contrary.
Visible images of toner on the OPC drum are transferred to the paper.
The high voltage of DC+3600V plus AC760V (P-P) is applied to the transfer roller to generate electric discharge between the roller and the OPC drum, generating positive and negative charges. Positive charges are attracted to the OPC drum and attached to the paper transported between the transfer roller and the OPC drum. Therefore the paper has a strong positive charge. Negatively charged toner on the OPC drum is attracted by the paper which is positively charged, and the visible images of toner are transferred onto the paper.
The paper is separated from the OPC drum. There is an electrostatic force between the paper, which is positively charged in transfer operation, and the OPC drum which is negatively charged. The positive charge on the paper is released to the separation electrode, which is the same potential as the aluminum layer of the OPC drum, to reduce the potential difference between the OPC drum and the paper, reducing the electrostatic force. This operation facilitates separation of the paper from the OPC drum.
The drum surface is discharged to facilitate cleaning of the drum surface. (The main charger roller easily collects the remaining toner.) The main charger is a rotating brush roller. The main charger removes residual toner from the OPC drum by its rotating sweeping action and causes it to stick to the brush. The main charger brush is in close contact with the mesh-type brush cleaning plate which removes toner and paper dust from the main charger brush mechanically.
OPC drum surface potential
Transition of OPC drums surface potential by print operation.
OPC drum surface potential and developing bias voltage in development.
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HOW TO DISASSEMBLE SHARP AM 400 - SHARP AM 300DE - LASER SCANNER COPIER PRINTER
Easy and simple disassembly/assembly procedures of some parts and units are omitted. refer to the Parts List.
To assure reliability of the product, the disassembly and the assembly procedures should be performed carefully and deliberately.REAR COVER REMOVAL
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PWB UNIT & PWB PLATE
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POWER SUPPLY [SMPS] SCHEMATIC [Circuit Diagram] - USING 2SK3326 (Power Switching) – LTV 817M-VB (Opto-coupler Isolator) - TOSHIBA 20A45C
Click on schematic to Zoom
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EPSON STYLUS PHOTO - R280 - R285 - R290 - HOW TO ADJUST PG
Adjust the distance between the head surface and the Paper Guide Front Assy (platen) properly and adjust the parallelism on the 0th column side and on the 80th columns side to ensure reliable print quality. Once the Carriage Assy and/or Adjustment Bushes have been removed or whenever necessary for any other reason, make this adjustment to correct the deviation of the platen gap.
Tools to be used
- Thickness gauge: 1.15 mm (x2) 1.3 mm (x2)
- Phillips screwdriver.
- The thickness gauge to be used must be free from dust and dirt and from deformation. Be sure to clean it before use. ! Take care that the Print Head is not soiled or scratched. To ensure high accuracy of adjustment, install new ink cartridges in the carriage, and move the carriage right and left by pulling the belt without holding the carriage.
- Make this adjustment after installing the mechanism unit in the Housing Lower. (Install the Linear Scale after adjustment.)
- With EPSON Stylus Photo R280/R285/R290, four stages of PG setting are available by means of the APG Mechanism. However, make this adjustment with the mechanism in the minimum PG position (PG-: 1.2 mm).
PG POSITIONS
PG POSITION AT PG ADJUSTMENT
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Adjustment procedure (Specified PG value: 1.2 ± 0.1 mm)
- Install new ink cartridges in the carriage.
- Remove the Cable Holder Frame.
- Check that the APG Assy and the carriage are in the PG-position.
- Move the carriage to the centre of the platen, and place 1.15 mm thickness gauge on the left aligning its left edge with the second rib of the Front Paper Guide. And place another 1.15 mm thickness gauge on the right aligning its right edge with the rightmost rib of the Front Paper Guide.
- Pull the Timing Belt to move the carriage to the left end.
- If the carriage comes in contact with the gauge, adjust the Left Parallelism Bush to raise the carriage to a position where the Print head does not come in contact with gauge.
- Pull the Timing Belt to move the carriage to the right end.
- If the carriage comes in contact with the gauge, adjust the Right Parallelism Bush to raise the carriage to a position where the Print head does not come in contact with gauge.
- Move the carriage to the middle area of the platen, and place 1.3 mm thickness gauges at the left and right ends of the platen.
- Pull the Timing Belt to move the carriage to the left end.
- If the carriage does not come in contact with the gauge, make the adjustment again.
- Pull the Timing Belt to move the carriage to the right end.
- If the carriage does not come in contact with the gauge, make the adjustment again.
- Mark the indicated graduation position of the right and left Parallelism Bush, and tighten the screws.(Screw tightening torque: 0.8±0.1 N•m)
PG ADJUSTMENT-2
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AUDIO OUTPUT SCHEMATIC DIAGRAM - TDA7495 - [Stereo] - AUDIOVOX FPE3000
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