BenQ PB8250 Service Manual
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BenQ PB8250 Service Manual

BenQ PB8250 Service Manual

Dlp projector
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DLP PROJECTOR
PB8250

SERVICE MANUAL

CONTENT
Chapter 1: Engineering Specifications.................................................................................................1
Appendix A Optical Measurement Procedure..............................................................................6
Chapter 2: Spare Parts List.................................................................................................................15
Chapter 3: Product description and operation....................................................................................17
Shipping Contents......................................................................................................................17
Projector Description .................................................................................................................18
Remote Control Description ......................................................................................................21
Installation..................................................................................................................................24
Operation....................................................................................................................................30
Packing Description ...................................................................................................................47
Appearance Description.............................................................................................................52
Lamp Replacement ....................................................................................................................55
Shutdown ...................................................................................................................................60
Shutdown ...................................................................................................................................60
Chapter 4: Circuit Operation Theory .................................................................................................61
Chapter 4: Circuit Operation Theory .................................................................................................61
Chapter 5: Alignment Procedure........................................................................................................69
Chapter 6: Trouble Shooting ..............................................................................................................73
Chapter 7: Schematics drawing..........................................................................................................83

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Summary of Contents for BenQ PB8250

  • Page 1: Table Of Contents

    DLP PROJECTOR PB8250 SERVICE MANUAL CONTENT Chapter 1: Engineering Specifications....................1 Appendix A Optical Measurement Procedure................6 Chapter 2: Spare Parts List.........................15 Chapter 3: Product description and operation..................17 Shipping Contents........................17 Projector Description .........................18 Remote Control Description ......................21 Installation..........................24 Operation............................30 Packing Description ........................47 Appearance Description......................52...

  • Page 2: Chapter 1: Engineering Specifications

    Chapter 1: Engineering Specifications...

  • Page 7: Appendix A Optical Measurement Procedure

    Appendix A Optical Measurement Procedure 1. Scope: This document describes critical optical related test definitions and Instructions for data or video projectors. The other general terminologies are specified in ANSI IT7.228-1997. 2. General Requirements The unit under test should be allowed to stabilize without further adjustment for a minimum of 5 minutes, at nominal ambient room temperature of 25°C, before making measurements.
  • Page 8 Note: L10, L11, L12, L13 are located at 10% of the distance from corner itself to L5 A2. ANSI UNIFORMITY ANSI +Uniformity= Maximum (L1~13)-Average (L1~9)/ Average (L1~9)% ANSI -Uniformity= Minimum (L1~13)-Average (L1~9)/ Average (L1~9)% A3. JBMA UNIFORMITY JBMA Uniformity = Average (L1,L3,L7,L9)/ L5 A4.
  • Page 9 JBMA Contrast = Average (L1,L2,L3,L4,L5,L6,L7,L8,L9) under solid white / Average (L1,L2,L3,L4,L5,L6,L7,L8,L9) under solid black A7. LIGHT LEAKAGE Leakage = The maximum light leakage under a solid black pattern in or outside of the projected image A8. IMAGE DISTORTION Keystone = (W2-W1)/ (W1+W2) x 100% Vertical TV dist = (H1+H2-2xH3)/2H2 x100% Horizontal TV dist = (W1+W2-2xW3)/2W1 x100% W1: image width at image bottom...
  • Page 10 center of the screen that is entirely the measured color under default brightness and contrast settings. A14. COLOR UNIFORMITY Color Uniformity is the maximum color difference ( x, △ △ y) between any two points out of L1~L13 A15. ANSI COLOR UNIFORMITY ANSI Color Uniformity: △...
  • Page 11 Step 2: Check specified screen sizes and zoom positions Step 3: Use Chart1 to measure Lateral Color for whole screen with Pattern 5 and record the maximum number Example if 0.6 pixel lateral color: A20. LAMP LIFETIME TEST PROCEDURE 50% lamp brightness maintenance under 3.5hr ON, 0.5hr OFF cycling test A21.

  • Page 16: Chapter 2: Spare Parts List

    SIGNAL/C 15/15P 20276 1800MM 50.J2103.501 CABLE RGA/DVI-A (WHDDC) 1.8M 50.J2401.001 CABLE D-SUB/RCA 1800MM/SL705X 50.L4302.501 CABLE AUDIO 284C/577C+CORE BL 54.J9412.001 BALLAST 300W O4 PB8250 OSRAM 55.J1313.001 PCBA 1L SENSOR-B BD SL700 X M 55.J5019.001 PCBA THERMAL BD DX850 55.J9401.001 PCBA MAIN BD PB8260 55.J9405.001 PCBA DC-DC BD PB8260 55.J9410.001...
  • Page 17 56.26J95.001 REMOTE PB8250 FORWARD 60.J8115.001 ASSY POWER+BRIDGE BD PB8250 60.J9418.001 ASSY SUB U/C PB8240 60.J9420.001 ASSY SUB L/C PB8240 60.J9420.002 ASSY SUB LOWER CASE PB8240 65.J7603.111 CW DIA46 DEG110 PB2240 PRODIS 65.J9301.001 PL ZOOM PB8240 COSINA 71.07XGA.B01 IC DMD 0.7XGA DDR 12 FTP PIXE 59.J8101.CG1...

  • Page 18: Chapter 3: Product Description And Operation

    Chapter 3: Product description and operation Shipping Contents The projector is shipped with the cables required for connection to a PC and to video equipment. Carefully unpack and verify that you have all of the items shown below. If any of these items are missing, please contact your place of purchase.

  • Page 19: Projector Description

    Optional Accessories 1. Macintosh adapter 2. 250W / 300W lamp module 3. Ceiling mount kit 4. Wireless Pro 5. Presentation Pro 6. DVI-I cable Projector Description...
  • Page 21 Controls and Functions...

  • Page 22: Remote Control Description

    Remote Control Description...
  • Page 23 Remote Control Effective Range Infra Red (IR) remote control sensors are located on the front and the back of the projector. The remote control must be held at an angle within 30 degrees of the projector’s IR remote control sensors to function correctly. The distance between the remote control and the sensors should not exceed 6 meters (19.5 feet).
  • Page 24 Installing or Replacing the Batteries...

  • Page 25: Installation

    Installation Choosing a Location Your projector is designed to be installed in the four installation configurations shown here: Floor front, Ceiling front, Floor rear, Ceiling rear. Your room layout or personal preference will dictate which installation configuration you use. If you place the projector above or below the screen, you have to tile it down or up to center the image on the screen, in these situations image distortion will occur.
  • Page 26 Connecting to a Laptop or Desktop Computer Connecting Equipment to the Component Video Input The projector is capable of displaying various High Definition TV display modes. Some of these sources are: Most of these sources will provide an analog component video output, a standard VGA output, or a YPbPr (default) format.
  • Page 27 The following standards are supported in the HDTV function: Connecting to Video or S-Video Devices Connecting to Display Devices If you want to monitor your presentation close-up on a monitor as well as on the screen, you can connect the RGB signal output port on the projector to an external monitor with a VGA cable or D-Sub - DVI cable.
  • Page 28 Adjusting the Height The projector is equipped with 2 quick-release adjuster feet. Screen Size Place the projector at the required distance from the screen according to the required picture size (see the table on the next page).

  • Page 31: Operation

    Operation Start Up 1. Switch all of the connected equipment on. 2. Plug the power cord into the projector and into a wall socket. 3. Turn on the wall socket switch (where fitted). 4. Turn the main power switch on. The Power indicator lights orange. 5.
  • Page 32 6. The start up procedure takes about 30 seconds after pressing Power. In the later stage of start up, a default BenQ logo appears. 7. Next, the projector starts to search input signals. Irrespective of selected input source, the screen shows “Acquiring Signal”...
  • Page 33 Source Selection Auto Adjustment...
  • Page 34 Blank Zoom / Focusing Adjust the projected image to your desired size using the lens’ zoom ring. Then focus the image by rotating the focus ring.
  • Page 35 Laser Pointer Operation The Laser Pointer is a presentation aid for professionals. It emits red colored light when you press it and the LED indicator lights up green. Do not look into the laser light window or shine the laser light beam on yourself or others.
  • Page 36 PIP (Picture In Picture) Operation By pressing the PIP-Source, PIP-Pos and PIP-Size hot keys, you can enable the PIP (Picture In Picture) function and choose the position and size of the PIP image. Freeze Preset Mode Selection...
  • Page 37 Menu Operation Menu System Please note that the OSD menus vary according to the signal type selected.
  • Page 38 Using the menus The projector is equipped with on-screen display (OSD) menus for making various adjustments and settings. There are 10 different menu languages. The following example describes the adjustment of the keystone.

  • Page 48: Packing Description

    Packing Description...

  • Page 53: Appearance Description

    Appearance Description...

  • Page 56: Lamp Replacement

    Lamp Replacement Use and Replacement of the Lamp When the Lamp Indicator lights up red or a message appears suggesting it is time to replace the lamp, please install a new lamp or consult your dealer. An old lamp may cause a malfunction in the projector and in some instances the lamp may explode.
  • Page 57 To reduce the risk of injuries to fingers and/or compromising image quality by touching the lens, do not touch the empty lamp compartment when the lamp is removed. This lamp contains mercury. Consult your local hazardous waste regulations and dispose of this lamp in the proper manner.
  • Page 58 Temp Warning Light When the Temperature warning light is on, it is warning you of the following possible problems: 1. The internal temperature is too high. 2. Air Filters are clogged. 3. The fans are not working. Turn the projector off , check that the air filters are clean. If the problem persists, contact qualified service personnel for further help.

  • Page 61: Shutdown

    Shutdown...

  • Page 62: Chapter 4: Circuit Operation Theory

    Chapter 4: Circuit Operation Theory PB8250 DMD projector being using the XGA DMD Engine made by BENQ, it included front end circuitry that digitizes and scaling processes for the input analog VGA and TV signals. As shown, in figure below the front end circuitry consists of : 1.
  • Page 64 2. DMD driver board that transfer PW166 scaler output RGB888 signal to DMD chip acceptable signal for driving DMD mirror operation. The relate diagram as below: 3. Whole system block diagram is show as below:...
  • Page 65 S-video Input Overview The Main Board of PB8250 is mainly composed of an ADC converter(AD9882), a ImageProcessor(PW166) , a EEPROM(24C16) and a flash memory (MBM29LV800B) . The input signal are DVI-I,DVI-A and analog RGB format , which comes from the standard DVI and VGA D_SUB connectors, the signal input to ADC converter , which output RGB digital data stream to Image Processor .
  • Page 66 The Flash memory stored the Software Program which control the system , the CPU will read the Flash as its execution command . Block Diagram Below is the simple block diagram of PB8250 Main Board . As the diagram shown above , here is the function of every discrete blocks . D_SUB input Analog RGB data input , the standard maximum analog input resolution is SXGA .There also...
  • Page 67 140MHZ , which is about SXGA 75HZ analog input signal(DVI resolutions up to SXGA 60Hz) . There are some other interface signals related to AD9882 SOGIN – Sync On Green input from Image Processor , the signal enable the PB8250 support the very special VGA input signal .
  • Page 68 DEN – Data enable signal output to DMD BD , provided as a valid data indicator signal for DMD driver. VCLK – V-port pixel clock. VPEN – V-port data enable. VVS – V-port Vertical Synchronization. VHS – V-port Horizontal Synchronization. VFILED –...
  • Page 69 software system will detect the abnormal signal. Sensor BD: The Sensor BD provides the color wheel index signal to DMD BD. The CWINDEX shall indicate the beginning of the red light on the DMD device. The phase of the display data on the DMD based on the CWINDEX signal.

  • Page 70: Chapter 5: Alignment Procedure

    Chapter 5: Alignment Procedure 1. DMD Bias Voltage Alignment Equipment: None Procedure: (1) Watch DMD “Bias Voltage Bin” Label (Example: 8060-7bbc DDDD XXXXXXX M ) (2) Switch the DIP switch (H8) on Chip board according to the red character on the DMD chip 00: E 01: D 10: C...
  • Page 71 Probe Procedure: (1) Probe impedance matches 50 ohm (2) Open Factory OSD, and select color wheel delay item (3) Leave the image pure red (DMD red curtain) (4) Put the detector on the screen that red image was projected. (5) Watch the oscilloscope and notice the square waveform (6) Use the “...
  • Page 72 4. S-Video and HDTV Color Adjustment Procedure Equipment: Pattern generator (VG-828) Lux meter ( CL-100) or CA 120 Procedure: (a) S-video adjustment(current source is S-video) (1) color spec x: 0.281±0.015 y: 0.297±0.015 (2) Change Timing and Pattern of pattern generator Timing:480i (60Hz) Pattern:80% Gray pattern (3) Adjust R.G.B 9300K Gain to match spec...
  • Page 73 If we line the x and y, then the Pb offset is the shift action and the Pr offset is the rotational action. (3) Connect power, YPbPr Video into projector. (4) Change Timing and pattern of pattern generator : Timing : 480P(H:31.54 KHz,V:60.08 Hz) pattern : black (5) Light on projector (6) Set user OSD values to default.

  • Page 74: Chapter 6: Trouble Shooting

    Chapter 6: Trouble Shooting Common Problems & Solutions...

  • Page 84: Chapter 7: Schematics Drawing

    Chapter 7: Schematics drawing...

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