Reference:
http://donsthings.blogspot.com/2019/02/replacing-k40s-digital-panel-with.html
https://www.google.com/search?q=k40-powerledto%2Banlogschem&newwindow=1&safe=active&rlz=1C1CHBF_enUS729US729&sxsrf=ALeKk03kmlRYNdFHWYsbr-D_OKtqk9Z2Vg:1586177343597&tbm=isch&source=iu&ictx=1&fir=PtwLYaKV1I5CpM%253A%252CYZgKoKM5n_JW8M%252C_&vet=1&usg=AI4_-kQA2VTQlMhH5rHU3TOyXpyeUAsxWA&sa=X&ved=2ahUKEwiTp_aI69PoAhUJWs0KHbWXCJ8Q9QEwA3oECAQQCw#imgrc=CzPjqk9S9T9T9M