Optoma GT750 User manual

SERVICE MANUAL
Prepare : Check: Approve:
Date Revise Version Description
2011.08.01 V1.0 Initial Issue
Mina Amy
GT750

GT750 Condential I
Preface
This manual is applied to GT750 projection system. The manual gives you a brief
description of basic technical information to help in service and maintain the product.
Your customers will appreciate the quick response time when you immediately identify
problems that occur with our products. We expect your customers will appreciate the
service that you offer them.
This manual is for technicians and people who have an electronic background. Please
send the product back to the distributor for repairing and do not attempt to do anything that
is complex or not mentioned in the troubleshooting.
Notice: The information found in this manual is subject to change without prior notice. Any
subsequent changes made to the data herein will be incorporated in future edition.
GT750 Service Manual
Copyright Aug. 2011
All Rights Reserved
Manual Version 1.0

GT750 Condential
II
Table of Content
Chapter 1 Introduction
Highlight 1-1
Compatible Mode 1-2
Chapter 2 Disassembly Process
Equipment Needed & Product Overview 2-1
Repair notice 2-2
Rod Adjustment 2-3
Re-write Lamp Usage Hour 2-4
Repair Action 2-5
Chapter 3 Troubleshooting
LED Lighting Message For Projector 3-1
Main Procedure 3-2
Chapter 4 Function Test & Alignment Procedure
Test Equipment Needed 4-1
Test Condition 4-1
I/O Port Test 4-2
Run In Test 4-8
Test Inspection Procedure 4-9
ADC Calibration 4-10
Restore Blower Speed 4-11
Chapter 5 Firmware Upgrade
Section 1: System Firmware Upgrade 5-1

GT750 Condential
III
Equipment Needed 5-1
Get into FW mode 5-2
Check FW version 5-2
Section 2: 8051 FW Upgrade (USB) 5-3
Equipment Needed 5-3
8051 Firmware Upgrade Procedure 5-4
Check 8051 FW version 5-5
Section 3: MST8535 Firmware FW Upgrade Procedure 5-6
Equipment Needed 5-6
USB Driver Upgrade Procedure 5-7
MST8535 Firmware Upgrade Procedure 5-9
Chapter 6 EDID Upgrade
EDID Upgrade Procedure 6-1
Appendix A Exploded Image I
Appendix B
Serial Number Denition I
PCBA Code Denition II

GT750  1-1
Chapter 1
Introduction
No  
1      
2
 
  
  
5




 

7 

  
  
10  

11  
12 





 
    
  
15 



  
1-1 Highlight

GT750  1-2
No  
17 



V 
          

  

 




1-2 Compatible Mode
Computer Compatibility (Analog/Digital)
Compatibility Resolution V-Sync [Hz] H-Sync [KHz]

  70
  
  
  70
  

  
 
  
  75

  
  
  75
  
 120
 75

GT750  
Compatibility Resolution V-Sync [Hz] H-Sync [KHz]

  
  
  75
 120
 75
  120
  

  
 
  
 
  75 

  
 50
 
 
 25
 
 50
 
  
 50
 

 50
 50
 
 
Note: If the Computer Compatibility supportive signal is different from User's Manual, please refer
to User's Manual.

GT750 Condential 2-1
Chapter 2
Disassembly Process
2-1 Equipment Needed & Product Overview
1. Screw Bit (+): 105
2. Screw Bit (+): 107
3. Screw Bit (-): 107
4. Hex Sleeves: 5 mm
5. Tweezers
6. Projector
* Before you start: This process is protective level II. Operators should wear electrostatic chains.
* Note: - If you need to replace the main board, you have to record the lamp usage hour.
- Some related contents please refer to common SM chapter 2.

GT750 Condential 2-2
2-2 Repair notice
Item Male Connector
on Main Board The key feature Figure
A & G Speaker Compose of Red/Black Wire and
Black wire tube (2 pin)
B Lamp Driver Black wire tube (5 pin)
CSystem Fan Compose of Red/Yellow/Black
Wire (3 pin)
D Photo Sensor Compose of Red/Black/White
Wire and Black wire tube (3 pin)
EBlower Compose of Black/Yellow/Red
Wire and Blue wire tube (3 pin)
FIR Compose of Black/Yellow/Red
Wire and Gray wire tube (3 pin)
Disassemble Main Board
Please refer to the below table details of
each connector on Main Board.
AG F E D C B

GT750 Condential 2-3
2-3 Rod Adjustment
1. Environment Adjustment
- The distance between the engine and
the screen is 93 CM.
- This process should be done at a dark
environment (under 10 Lux).
2. Procedure Adjustment
- Change the screen to "white screen".
- Adjust the screws on the engine module
to readjust the image.
("screw 1" should be adjusted rst, and
then "screw 2". Adjust until the yellowish
or bluish parts disappeared.)
3. Abnormal image inspection
- It should not have any abnormal color
at the rim of the image by estimating
through the eyes.
Note: - To avoid over adjusting the rod.
- After the operation, please use the glue
to x the screws.
Screw 1
Screw 2