Flipper is preset to work Vizio and LG, and some other common TVs. Press Volume to test.
If not working, then look for the manufacturer of the device below and use these codes.
TVs
Curtis: 2001
Emerson: 3301
fireTV: 2621
fireTV (Omni): 2621
fireTV (Insignia): 3961 (or try Dynex codes)
GE Projection: 1111
Haier:: 5761
HiSense (Roku): 6721
Insignia: 3961
JVC: 3971, 6691, 2581, 1741, 1791, 6661, 2601, 6301, 5181, 4751,
JVC Roku: 6691
LG: preset code or 3671
ONN: 6691, 3441
Philips: 3801
Philips Roku: 6691, 3381
RCA: 1721, 6651, 6641, 5431, 3671, 3381, 6401, 4001
RCA Roku: 3381, 6641
Samsung:: 3831
Sceptre: 2491, 5951, 2501, 6741
Sharp: 3421, 2851, 3861,
Sharp Roku: 6601
Sony:: 3611,
Westinghouse: 3391, 2291,
Westinghouse Roku 3971, 3961
Viore: 1791, 2091,
Vizio: preset code
TCL: 3381 3441, 4141, 4131, 5281, 4981, 3541, 1481,
TCL Roku: 3381
TCL Fire TV: Preset code, 4441, 2621
TCL Google TV: 3441
Philips: 3801
Philips Roku: 6691, 3381
Sceptre: 2491, 5951, 2501, 6741
Sharp: 3421, 2851, 3861,
Sharp Roku: 6601
Westinghouse: 3391, 2291,
Westinghouse Roku 3971, 3961
Viore: 1791, 2091,
Vizio: preset code
TCL: 3381 3441, 4141, 4131, 5281, 4981, 3541, 1481,
TCL Roku: 3381
TuTu:: see RCA