Apple cinema hd display 23 lcd User Manual

							
 

Apple Cinema HD Display 23 - 
 
1
 
 Symptom Charts
 
Symptom Charts
 
How to Use the Symptom Charts
 
The Symptom Charts included in this chapter will help you diagnose specific symptoms 
related to the product. Because cures are listed on the charts in the order of most likely 
solution, try the cures in the order presented. Verify whether or not the product continues 
to exhibit the symptom. If the symptom persists, try the next cure. 
 
Note:
 
  If you have replaced a module, reinstall the original module before you proceed to 
the next cure.
 
Note:
 
  Referring to the Block Diagram in this manual may be helpful.
 
Blank screen
 
This symptom may indicate a problem with the LCD panel, backlight bulbs, inverter, main 
board, or related cables or connectors.
1. Check ADC cable. Replace cable if damaged.
2. Check for bent pins in the ADC connector (note, it is normal for two of the pins to be  slightly longer than the others). If pins are slightly bent, carefully straighten. If pins are 
severely bent, replace cable. Also, inspect or have the customer inspect the display 
port on the computer for broken pin dividers. If the display port is damaged it must be 
repaired before inserting the ADC connector.
3. Plug the display into a known-good computer with a known-good video card and ADC  display port. Boot the computer and allow enough time to  finish booting.
4. If the power button on the display is  flashing, two short  flashes then a long  flash, in a 
delayed repeating pattern, this indicates trouble with either the inverter, backlight 
bulbs or related cables or connectors. With this in mind, continue with the 
troubleshooting steps to determine the problem. 
						

							
 

2 - 
 
Apple Cinema HD Display 23 Symptom Charts
5. To check whether the LCD is working, press the launch button on the display which 
will bring up the Display Preferences window (if the screen is blank you will not see the 
window). Shine a bright light such as sunlight or a high intensity lamp (see Important 
note, below) into the screen and at the same time notice whether you can see a faint 
image of the Display Preferences window or other desktop items on the screen. 
• If desktop items can be seen, the LCD panel is working. The problem may \
be with the inverter or backlight bulbs or related cables or connectors. Continue with the 
troubleshooting steps.
• If no desktop items can be seen, the problem may be with the LCD panel o\
r the  main board or related cables or connectors.
 
Important: 
 
Lights get very hot and can quickly damage the display; be extremely 
careful not to allow too much heat next to the screen or other parts of \
the display and 
do not allow the light fixture to touch the screen, or damage can result\
.
 
6. Warning: The inverter board generates high voltage when the display is plugged  in. Do not touch the inverter board components, pins or connectors, when the 
display is connected to the computer.
 
Disconnect the display from the computer, then open the display and chec\
k for 
secure connections at TMDS, Panel Power, J703, J701, J702, J12, CN1, CN2\
, CN3, 
CN4 and CN5.
 
Note:
 
 Refer to the Block Diagram in this manual for connector locations.
7. Plug the display into a known-good computer, then boot the computer.
8. Verify +24-28V at input of J702. If not, replace ADC cable.
9. Verify +24-28V at pin 10 of J701. If not, replace the main board.
10. Verify +5V at pin 11 of J703. If not, replace the main board.
11. Verify +18V at pin 6 of J703. If not, replace the main board. 
						

							
 

Apple Cinema HD Display 23 - 
 
3
 
 Symptom Charts
 
Partially dim screen
 
This symptom indicates a problem with the inverter or backlight bulbs (on the side of the 
display that is dim), or related cables or connectors. This may be caused by the backlight 
bulbs or the inverter not working properly.
1. Plug the display into a known-good computer with a known-good video card and ADC display port. Boot the computer.
2. Notice whether the power button on the display is  flashing, two short  flashes then a 
long  flash, in a delayed repeating pattern. This indicates trouble with either the 
inverter, backlight bulbs or related cables or connectors (this indicator may not always 
be exhibited). With this in mind, continue with the troubleshooting steps to determine 
the problem.
 
3. Warning: The inverter board generates high voltage when the display is plugged  in. Do not touch the inverter board components, pins or connectors, when the 
display is connected to the computer.
 
Disconnect the display from the computer, then open the display and chec\
k for 
secure connections at CN1, CN2, CN3, CN4 and CN5.
 
Note:
 
 Refer to the Block Diagram in this manual for connector locations.
4. Replace inverter.
5. Replace LCD panel.
 
Display remains dimly lit although computer is shut down
 
Note:
 
 A dimly lit display may be visible only in a dark room. 
1. Shut down the computer and display.
2. Darken the room or drape a large dark cloth, such as a blanket, over the display to  simulate a dark environment. Check for faint screen brightness.
3. If the display remains dimly lit, replace the inverter board. 
						

							
 

4 - 
 
Apple Cinema HD Display 23 Symptom Charts
 
USB device not working
 
1. Check for bent pins in the ADC connector (note, it is normal for two of the pins to be 
slightly longer than the others). If pins are slightly bent, carefully straighten. If pins are 
severely bent, replace cable. Also, inspect or have the customer inspect the display 
port on the computer for broken pin dividers. If the display port is damaged it must be 
repaired before inserting the ADC connector.
2. Plug the display into a computer with a known-good ADC display port, then boot the  computer. On the back of the display, connect a known-good USB device into one of 
the USB ports, then check Apple System Pro filer to see if it is recognized. Check both 
USB ports.
 
Note:
 
 
 
x 
+R, refreshes the Apple System Profiler list when USB devices are change\
d.
• If the device is recognized, the customer’s USB device may be the iss\
ue.
• If not, check the J11 and J12 USB connections and cables. If not that, r\
eplace the  main board.
 
Touch switch not working
 
1. Check J705 or J704 connections and cables.
2. Check J12 connection and cable.
3. Replace touch switch.
4. Replace main board. 
						

							
 

Apple Cinema HD Display 23 - 
 
5
 
 Symptom Charts
 
When displaying a single color over the screen area, the LCD panel shows one 
or more pixels that are not properly lit
 
Active-matrix LCD technology uses rows and columns of addressable locations (pixels) 
that render text and images on screen. Each pixel location has three separate subpixels 
(red, green, and blue) that allow the image to be rendered in full color. Each subpixel has a 
corresponding transistor responsible for turning the subpixel on or off.
There are typically millions of these subpixels on an LCD display. For example, the LCD 
panel used in the Apple Cinema HD display is made up of 2.3 million pixels and 6.9 million 
red, green, and blue subpixels. Occasionally, a transistor does not work perfectly, which 
may result in the affected subpixel being turned on (bright) or turned off (dark). With the 
millions of subpixels on a display, it is quite possible to have a low number of faulty 
transistors on an LCD. Therefore, a certain number of subpixel anomalies is considered 
acceptable. Rejecting all but perfect LCD panels would significantly increase the retail 
price for products using LCD displays. These factors apply to all manufacturers using LCD 
technology—not just Apple products.
To determine whether or not the display has an acceptable number of pixel anomalies, 
follow the steps below:
1. Set the display image to one of the following colors: all-white display, all-red display,  all-green display, or all-blue display. 
 
Note:
 
 Knowledge Base article 112125: Service Diagnostics Matrix, has the LCD \
Tester Diagnostic Utility that will generate these patterns on the scree\
n.
2. Using a jeweler’s loupe, pocket microscope, or other magnifying device, identify and  count each subpixel anomaly:
• Bright subpixel anomaly = subpixel that is always on
• Dark subpixel anomaly = subpixel that is always off
3.
 
Important:
 
 Check the number of subpixel anomalies with the following chart:
4. If the number of subpixel anomalies exceeds the acceptable number listed in the  chart, replace the display panel.
5. If the number of subpixel anomalies is acceptable, explain to the customer that the  pixel anomalies are within speci fications, and no repair is necessary. 
 
Important:
 
  Do not release the specifications to customers. Instead, inform them t\
hat 
a certain number of subpixel anomalies is considered acceptable, and these factors 
apply to all manufacturers using LCD technology—not just Apple products.
 
Acceptable Number of Subpixel 
Anomalies Replace the Display
 
Bright
Dark Combination BrightDark  Combination
up to 8 up to10 up to 15 8  or more 11 or more 16 or more 
						

							
 

© 2003 Apple Computer, Inc. All rights reserved.
 

 
 
 
Service SourceViews
 
Apple Cinema HD Display 23 LCD (ADC) 
						

							
Apple Cinema HD Display 23 Views - 1
1 ylbmessA tooF 7755-229 1 
1 egniH ,paC 8755-229 2 
 3 922-5576 Cover Assembly, Rear (with blank serial # label) 1
1 raeR ,dleihS 7075-229 4 
 5 922-5580 Shield, EMI, LCD (includes EMI sponges, not assembled) 1
1 ylbmessA egniH 9755-229 6 
1 retrevnI ,draoB 1855-229 7 
1 niaM ,draoB 2855-229 8 
1 BSU ,revoC 3855-229 9 
1 tekcoS BSU ot BLM ,elbaC 4855-229 01 
1 CDA ,niaM ,elbaC 5855-229 11 
1 rewoP lenaP DCL ot BLM ,elbaC 6855-229 21 
1 sissahC 6790-670 31 
1 32 ,DCL ,yalpsiD 9672-166 41 
 15 922-5574 Bezel Assembly, Front (does not include logo) 1
2 hctiwS hcuoT ,tooB 1455-229 61 
2 hcuoT ,hctiwS 0355-229 71 
1 rewoL ,thgilkcaB ,bluB )dereffO toN( 81 
1 reppU ,thgilkcaB ,bluB )dereffO toN( 91 
1 rennI ,lezeB 5755-229 02 
1 tiK lebaL tneV 7790-670 12 
desU .ytQnoitpircseD.oN traPmetI
ExplodedView Parts List 
						

							
 

2 - 
 
Apple Cinema HD Display 23 Views Exploded View
 
Exploded View
  
LA291Z
Exploded View
6
5
8
11
14
20
15
1716
13
127
9
10
19
18
1
2
3
4
21 
						

							
Apple Cinema HD Display 23 Views - 3 Exploded View
LA291Z
J705
J704
J702J701J703CNC7
CNC6
J11
CN1
CN2
CN3
CN5
CN4
J12
J1
J1
Wiring Diagram
Cable, MLB to Inverter
922-5589
Cable, MLB to USB Socket
922-5584
Cable, MLB to Power Switch
922-5587
Cable, MLB to Launch Switch
922-5588
Main Board
922-5582
Inverter Board
922-5581
Cable, Main, ADC
922-5585Backlight Bulb, Upper
(Not Offered)
Backlight Bulb, Lower
(Not Offered)
Cable, MLB to LCD Panel Power
922-5586 
						

							
 

4 - 
 
Apple Cinema HD Display 23 Views Block Diagram
 
Block Diagram
 
TMDSLCD
Panel Power
J701
J703
CN4
CN5
CN3
CN1
CN2
USB Ports Internal - Rear View without Rear Cover
Inverter Board Main Board
J702
J12
J11
J705 J704
Backlight Bulbs, Upper
Backlight Bulbs, Lower
Power Switch Launch Switch
Block Diagram