Specifications

LED Cinema Display (24-inch) Troubleshooting — General Troubleshooting 16
2010-02-08
Test Points Diagram
Refer to this diagram to see the location of test points and instructions for their use:
Below are main logic board test points that you can use
to verify proper power flow in LED Cinema Display (24-inch).
All voltages assume that the display is plugged into
a power outlet, and NOT into the host computer (unless
otherwise noted).
• Turn the dial of your voltmeter/multimeter to measure
DC (direct current) . If your voltmeter requires that
you set a voltage range, choose a DC range that includes
the voltage that you are measuring.
• Connect the black probe to ground by gently inserting into
any of the LCD screw posts closest to the logic board.
Keep in mind that the threading in the screw posts is fragile
and can be easily destroyed.
• Touch the red probe to appropriate test point.
• Verify voltage.
DC In
TP 11: 24.5 VDC
TP 12: 24.5 VDC
TP 13: 12.0 VDC
*TP 14: 5.0 VDC
*only if USB plugged into host
USB Hub 1 for 3 ports
*TP 21: 3.3 VDC
*TP 22: 5.2 VDC
*TP 23: 5.2 VDC
*TP 24: 5.2 VDC
*only if USB plugged into host
USB Hub 2 for camera & audio
*TP 31: 3.3 VDC
*only if USB plugged into host
LED Backlight Driver
TP 81: 24.5 VDC
TP 82: 1.0 VDC
TP 61: 3.3 VDC
Warning:
HIGH VOLTAGE: Use extreme caution
when live testing.
• Never touch the power supply.
• Do NOT lean over or accidentally touch
power supply area during live testing.
• Keep your fingers behind the finger
guards on the test probes when making
measurements on main logic board!