Did u remove the dvd rom compartment?
Look carefully and one of the cable with the white 3pin connector

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Thanks rayzine! Recheck the Antec case and found the 24-pin power to 24-pin with 3-pin extension that connects to the white connector. Now the LCD works!

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U r welcome.  
Good.  Yes, it a bit tricky to use the external 24 pin power cord.

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