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3M

 Multimedia Projector MP8620

Disassembly/Reassembly

 3M 1999

2-8

2

1

3

3

4

4

5

6

7

2-3-5.

 

Remove Power Distributor

To avoid electrical shocks, unplug projector
power cord before performing any maintenance
to electrical components.

To avoid burns to fingers, allow projector lamp
and internal projector components to cool off prior
to lamp removal or disassembly.

Remove lamp assembly and power supply.

1.

 

Remove three (3) screws securing cover.

2.

 

Lift edge of cover toward front of machine first and
then remove.

3.

 

Disconnect three (3) cable connectors.

4.

 

Disconnect two (2) ribbon cables.

5.

 

Remove one (1) screw to disconnect ground.

6.

 

Disconnect two (2) ribbon cables.

7.

 

Remove two (2) screws (one on each side).

8.

 

Remove power distributor.

9.

 

Reassemble in reverse order.

 !

Caution

 

!

WARNING

Summary of Contents for Multimedia Projector MP8620

Page 1: ...3M Visual Systems Division Printed in U S A 6801 River Place Boulevard 3M 6 99 78 6970 8988 2 Rev A Austin Texas 78726 9000 MP8620 Multimedia Projector Service Manual ...

Page 2: ...1 Image Adjustments 1 11 1 11 1 Adjusting the display resolution and brightness and contrast 1 11 1 11 2 Part 2 Adjusting the tracking to remove vertical bands in the projection image 1 12 1 11 3 Part 3 Adjusting the Sync pixel frequency and scanning frequency 1 13 2 Disassembly Reassembly 2 1 2 1 Overview 2 1 2 2 Required Tools 2 1 2 3 Steps for Removing Projector Components 2 1 2 3 1 Remove Top ...

Page 3: ...ory and Diagrams 4 1 4 1 Overview 4 1 4 2 Theory of Operation 4 1 4 2 1 Power Supply Circuit 4 1 4 2 2 Video Input and AD Conversion 4 1 4 2 3 RGB Input and AD Conversion 4 2 4 3 Color Theory 4 3 4 3 1 Color 4 3 4 3 2 Electromagnetic Spectrum 4 3 4 4 LCD Structure Theory 4 4 4 4 1 LCD Cells 4 4 4 4 2 How Light Passes Through An LCD 4 4 4 4 3 Example Projection 4 4 4 5 Lamp Theory 4 5 4 6 Keystone ...

Page 4: ...P8620 are very sensitive to static energy A simple static charge can ruin a circuit board instantly Because of this it is essential that you complete all repairs in a static safe work environment 1 2 1 Static Safe Work Environment A properly grounded floor mat table mat and adjustable wrist strap with grounding cord are needed for complete static protection 3M recommends any of the following works...

Page 5: ...to connect the original disassembled power supply with the interface board LCD Alignment Tool Used to check that the LCD alignment is at an 8 degree angle Backlight Light Source Used to check the disassembled LCD unit without the original machine lamp source Voltmeter Used to measure the voltage at particular test points 3M recommends the Fluke model 87 Oscilloscope 100 MHz Used to check the video...

Page 6: ...ress and hold both the Enter button and the Down Arrow button on the control panel 2 Turn the main power switch to on The default settings are restored and the following message appears Parameter Factory Settings Restored Resetting a projector to its default factory setting may resolve a no input detected error message for an RGB or video input device ...

Page 7: ... image Note Remove any dust from the outside of the projection lens with a lint free cloth If dust remains on the projection image the LCD panel needs to be cleaned 1 6 2 Cleaning the Dust from LCD If dust particles can be seen on your projection image 1 Turn off the main power switch of the projector and unplug the power cord 2 Remove the LCD module assembly Refer to the appropriate Disassembly R...

Page 8: ...stalling a new LCD ribbon cable is done using the following steps 1 Gently pull out the white plastic clamp on the LCD and interface board connectors to release the LCD ribbon cable 2 Insert one end of the new ribbon cable into the LCD connector The blue side of the cable should be facing up 3 Insert the other end of the new ribbon cable into the interface board connector The blue side of the cabl...

Page 9: ... facing up 3 Insert the other end of the new ribbon cable into the interface board connector The blue side of the cable should be facing down 4 Lock the white plastic clamps into place on both the LCD connector and the Interface board connector 5 Use the old cable as a pattern to place the appropriate bends in the new cable If a connector clamp is broken Order a complete connector DY 0205 1512 7 R...

Page 10: ...the interface board to the power board with the Service Interface Cable DY 205 1500 1 7 Place a cover over the power supply board to prevent damage or injury Because the power supply board is fully energized in the next step it is essential that a cover is placed over the board to prevent injury 8 Power up the projector 9 Measure the voltage of pin 9 on the test block This connector is nearest the...

Page 11: ...p should be aligned using the reflection image on the lamp reflector The image of the lamp should be slightly above or slightly below the lamp 4 If not this position can be changed by turning the two adjustment screws below the lamp sockets 5 Verify the lamp alignment by powering up the projector and viewing the image of the lamp on the screen This can be done by holding a triplet lens in front of...

Page 12: ...gs under the lamp socket Note If the arcs are too close the lumen output will be reduced If the arcs are to far apart the image uniformity will be affected 2 Verify the lamp alignment by powering up the projector and viewing the image of the lamp on the screen by holding a triplet lens in front of the projector lens 3 Repeat the above two steps until the lamp is aligned correctly ...

Page 13: ...em Lamp is Green the lamp is good When the bar turns red or the projection image appears dark the lamp and air filter should be replaced 1 10 1 Reset the Lamp Life Indicator 1 Under the Option sub menu select the sub menu item Lamp and press Enter 4 Follow the instructions in the Help Window 5 Press the Enter button and the Up Arrow button on the control panel for confirmation ...

Page 14: ...ntrol Stick on the remote control to select the Palette sub menu item 12 Press the left right Arrow buttons on the projector or the Control Stick on the remote control left right to reduce the chromatic resolution from the default that is 16 7 million colors to 64 13 Press the up down Arrow buttons on the projector or move the Control Stick on the remote control to select the Pixels sub menu item ...

Page 15: ...ress the up down Arrow buttons on the projector or move the Control Stick on the remote control to select the Tracking sub menu item 6 Press the left right Arrow buttons on the projector or move the Control Stick on the remote control left right to reduce the amount of interference 7 The direction of adjustment is correct when the number of lines decreases The setting is optimal when no interferen...

Page 16: ...m 6 Press the left right Arrow buttons on the projector or move the Control Stick on the remote control left right to reduce the amount of fuzziness or flicker in the projection image An automatic setting of synchronization can be called up by pressing the Enter button 7 Complete fine adjustments to the brightness and contrast settings if minor interference still remains Press the Menu button to e...

Page 17: ...electrical shocks unplug projector power cord before performing any maintenance to electrical components To avoid burns to fingers allow projector lamp and internal projector components to cool off prior to lamp removal or disassembly 2 2 Required Tools An entire disassembly and reassembly can be completed with the following tools Phillips screwdriver 1 magnetic long shaft Standard screwdriver 3 1...

Page 18: ...o electrical components To avoid burns to fingers allow projector lamp and internal projector components to cool off prior to lamp removal or disassembly 1 Lift the two cover latches lift the cover into the projection position 2 Carefully pry off two 2 cover hinges 3 Lift rear of top cover up 4 Slide top cover forward toward projection lens 5 Reassemble in reverse order Caution WARNING ...

Page 19: ...g projector power cord before performing any maintenance to electrical components To avoid burns to fingers allow projector lamp and internal projector components to cool off prior to lamp removal or disassembly Remove top cover 1 Remove two 2 screws 2 Lift EMI shield up to remove 3 Reassemble in reverse order Caution WARNING ...

Page 20: ...or lamp and internal projector components to cool off prior to lamp removal or disassembly 1 Remove two 2 screws from bottom of base 2 Depress lock tab and slide cover to remove 3 Lift latch to release lamp panel and lower panel to the open position Note Do not touch lamp glass with fingers Oil from fingers can reduce lamp life 4 Release wire from wire holder 5 Return lamp panel to the closed posi...

Page 21: ...er up then slide it forward to remove 9 Remove the IR filter Notice the position of the filter for reassembly The fins point downward and out 10 Remove light shield by pulling it up and out 11 Disconnect two 2 wire connectors from the thermostat 12 Loosen two 2 screws on the white lamp leads and carefully disconnect wires 13 Remove one 1 screw to disconnect two 2 ground wires ...

Page 22: ...isassembly Reassembly 3M 1999 2 6 14 15 15 14 Feed lamp wire leads through front of lamp housing 15 Remove four 4 Torx head screws to free lamp assembly Carefully lift lamp assembly out of projector body 16 Reassemble in reverse order ...

Page 23: ... EMI shield 1 Remove the lamp wire leads from the power supply board at the fan end These leads connect to the lamp ignitor 2 Disconnect the ten pin PCB Interface connector 3 Disconnect the three pin power connector 4 Disconnect all fan cables four 4 connectors in a block that are opposite the cooling fan These cables are connected in parallel and do not need to be reconnected in the exact same co...

Page 24: ... internal projector components to cool off prior to lamp removal or disassembly Remove lamp assembly and power supply 1 Remove three 3 screws securing cover 2 Lift edge of cover toward front of machine first and then remove 3 Disconnect three 3 cable connectors 4 Disconnect two 2 ribbon cables 5 Remove one 1 screw to disconnect ground 6 Disconnect two 2 ribbon cables 7 Remove two 2 screws one on e...

Page 25: ...s to fingers allow projector lamp and internal projector components to cool off prior to lamp removal or disassembly Remove the lamp and the power supply 1 Remove three 3 screws securing cover 2 Lift edge of cover toward front of machine first and then remove 3 Disconnect LCD ribbon cable 4 Feed LCD ribbon cable through EMI ferrite 5 Remove two 2 cable ties 6 Remove two 2 screws from left side LCD...

Page 26: ...ltimedia Projector MP8620 Disassembly Reassembly 3M 1999 2 10 7 8 9 7 Remove two 2 screws from right side LCD assembly pivot bracket 8 Remove one 1 e ring 9 Remove LCD assembly 10 Reassemble in reverse order ...

Page 27: ...or power cord before performing any maintenance to electrical components To avoid burns to fingers allow projector lamp and internal projector components to cool off prior to lamp removal or disassembly Remove the top cover 1 Remove four 4 screws two on each side to release the lens 2 Reassemble in reverse order Caution WARNING ...

Page 28: ... fingers allow projector lamp and internal projector components to cool off prior to lamp removal or disassembly Remove the lamp assembly and power supply 1 Remove three 3 screws securing cover 2 Lift edge of cover toward front of machine first and then remove 3 Disconnect two 2 cable connectors 4 Remove four 4 screws two on each side from left and right speaker brackets 5 Remove speakers 6 Reasse...

Page 29: ...efore performing any maintenance to electrical components To avoid burns to fingers allow projector lamp and internal projector components to cool off prior to lamp removal or disassembly Remove the top cover 1 Disconnect one 1 cable connector 2 Remove one 1 screw from IR receiver board 3 Remove IR receiver board 4 Reassemble in reverse order Caution WARNING ...

Page 30: ...t Failure Troubleshooting Flow Charts General Projection Image Troubleshooting 3 3 Direct Failure Troubleshooting Flow Charts The troubleshooting flow charts listed in this section start with the basics and move forward They are designed to be used for solving direct failure problems The following problems can be resolved using the troubleshooting flow charts Projector Does Not Power Up Lamp Does ...

Page 31: ...Is the LCD switch fully engaged Is the fuse on the power supply functioning properly Is the lamp access door closed completely Projector Does Not Power Up Close the lamp access door Close top cover reopen completely Adjust switch position replace switch if faulty Replace fuse Replace the power supply Yes Yes Yes Yes Yes No No No No ...

Page 32: ...3M Multimedia Projector MP8620 Troubleshooting 3M 1999 3 3 3 3 2 Lamp Does Not Light ...

Page 33: ...3M Multimedia Projector MP8620 Troubleshooting 3M 1999 3 4 3 3 3 Projector Image Problem ...

Page 34: ... properly functioning Is the interface board powering the LCD Does the menu screen appear when the projector is powered on LCD Not Functioning Refer to Projector Does Not Power Up Check input device and cabling Replace pinched or broken ribbon cables Check connections Replace interface board if needed Replace the LCD unit Yes Yes Yes Yes Yes No No No No ...

Page 35: ... wires connected and functioning Is the audio board receiving power from the power supply Is the audio input device connected properly No Sound Check input device cabling and input device Replace speaker Reconnect repair or replace wires as needed Check connections and cabling Replace the audio board Yes Yes Yes Yes Yes No No No No ...

Page 36: ...tup menu for optimum performance 3 4 2 No Computer Image Projected Message No input detected is shown Probable causes are Loose cable No power to computer Wrong synchronization mode Possible solutions are Check and secure cable connections Turn on computer Adjust synchronization mode of the projector to the synchronization mode of the computer via Option menu 3 4 3 No Video Image Projected Probabl...

Page 37: ...formance 3 4 6 Cannot Get Entire Image on the Screen Probable causes are Wrong Tracking value Compatibility problem Wrong pixel setting Possible solutions are Refer to the documentation of your graphic card The projector supports the resolutions that can be found under Pixel in the Setup menu Adjust the Pixel setting in the Setup menu to the resolution of the video mode output from the computer gr...

Page 38: ...om the projector Connect all sources to a common power source Remove antenna connection from VCR If the disturbance disappears use a bypass filter isolating transformer to connect the antenna to the VCR Try different input source 3 4 9 No Power Power Shuts Off During Presentation Probable causes are Power switch OFF Projector overheated Possible solutions are Turn on Power switch to projector Remo...

Page 39: ...ocessor to power the rest of the projector 4 2 2 Video Input and AD Conversion There are two sets of video inputs Switching between them is done using the input button on the top of the projector or the Video1 2 button on the remote control Signal Board The video signal passes though the video signal selector then to the comb filter where it is split into the chroma signal C It is then sent to the...

Page 40: ...l Signal Board The RGB signal goes through a RGB1 2 signal selector then the chroma signal C information is sent to the video RGB selector and the luminal signal Y information is sent to sync selection Driver Board Refer to driver board information for video RGB Out RGB out simply takes the information in its analog state and passes it through an amplifier to the terminal out Additional electronic...

Page 41: ... measurable wavelength or combination of wavelengths The wavelengths of light are not colored but produce the sensation of color 4 3 2 Electromagnetic Spectrum All wavelengths of light are part of the electromagnetic energy spectrum The spectrum is a continuous sequence of energy waves that vary in length from short to long Visible light the wavelength that our eyes can detect is only a small port...

Page 42: ...ht to pass through the pixels Shades of gray are obtained by inputting voltages that fall between full off no voltage and full on full voltage The cells are refreshed at the speed of 1 60th of a second and are sensitive to high temperatures 4 4 2 How Light Passes Through An LCD Polarized light entering the cells from the rear is aligned so that it will pass the light through the polarizer on the o...

Page 43: ...e bulb is capable of producing 450 lumens of uniform brightness across the entire projection image The metal halide bulbs should never be touched When oil from your skin touches the bulb it provides a focal point for the lamp energy The lamp burns hotter at that location and eventually burns through the bulb prematurely ...

Page 44: ...angle is greater than sixteen degrees As the front of the projector is raised the projection angle increases At sixteen degrees the projection image is still square and in focus at nineteen degrees keystoning can be seen The MP8620 is keystone corrected at a ratio of 3 9 to 1 to provide a square focused image as shown Restated for every 3 9 feet of projection distance the image is raised 1 foot Th...

Page 45: ...ows light waves at the right angle to pass through Hot Mirror Heat management device that passes the light and reflects heat IR and UV light Cold Mirror Reflector Heat management device that reflects the light and passes heat IR and UV light LCD Panel Positions the liquid crystal cells that form an image Cold Mirror IR and UV Light Lamp Condenser Lens Lamp Side Fresnel Hot Mirror LCD Lens Side Fre...

Page 46: ...3M Multimedia Projector MP8620 Theory and Diagrams 3M 1999 4 8 4 8 Connection Diagrams Electrical diagrams provide a visual representation of how the projector circuitry is connected ...

Page 47: ...3M Multimedia Projector MP8620 Theory and Diagrams 3M 1999 4 9 4 9 Wiring Diagrams Wiring diagrams provide a visual representation of how the projector is wired ...

Page 48: ...rnal cable failure problems 4 10 1 Interface Board Connector Locations Power Supply Connector J10 Pin 1 of the connector is the black cable and pin 10 of the connector is the red cable 1 2 5 Volt 3 5 Volt 4 12 Volt 5 12 Volt 6 7 Ground 8 Lamp on 5Volt TTL high Lamp off 0 Volt TTL Low 9 Dimmer Standard 0 Volt TTL low Economy 5 Volt 10 Fan on 5Volt TTL high Fan off 0 Volts TTL low ...

Page 49: ...r MP8620 Theory and Diagrams 3M 1999 4 11 4 10 2 Audio Board Connector Locations Video Out J1 This connector joins the audio and interface boards Video In J2 Allows for video input from the interface board to the audio board ...

Page 50: ...media Projector MP8620 Theory and Diagrams 3M 1999 4 12 4 11 Computer Video Audio Connections The information provided in this section is for reference purposes Each type of cable is shown with a pinout diagram ...

Page 51: ...3M Multimedia Projector MP8620 Theory and Diagrams 3M 1999 4 13 ...

Page 52: ...t forth in a written agreement signed by an authorized officer of 3M Warranty and Limited Remedy This product will be free from defects in material and manufacture for a period of two years from the date of purchase 3M MAKES NO OTHER WARRANTIES INCLUDING BUT NOT LIMITED TO ANY IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE If this product is defective within the warranty p...

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