LG 55LN5100 compatibility

[static418]

Was wondering if LG model 55LN5100 could be added/is compatible? Manual link below. Commands seem to be standard-ish, but even after adding the model number to the 'LK450_etc' group which at least let me try to issue generic power on/off and input commands, the response to every command is 'none'. The manual specified for this model covers somewhat of a swath, and it doesn't seem to refer to this model specifically. However, it does still have the 'service only' jack on the side, so I can only assume it's good for something. I'm willing to try just about anything, and I have just about every kind of adapter you could think of. I've used two different types of USB to serial adapters as well as an Arduino as a serial adapter which lets me switch the Tx/Rx pins.

http://www.lg.com/us/lgecs.downloadFile.ldwf?DOC_ID=KROWM000560756&what=MANUAL&fromSystem=LG.COM&fileId=KROWM000560756.pdf&ORIGINAL_NAME_b1_a1=MFL67651192_04%2Brs.pdf