core/homeassistant/components/hdmi_cec/icons.json

{
  "services": {
    "power_on": {
      "service": "mdi:power"
    },
    "select_device": {
      "service": "mdi:television"
    },
    "send_command": {
      "service": "mdi:console"
    },
    "standby": {
      "service": "mdi:power-standby"
    },
    "update": {
      "service": "mdi:update"
    },
    "volume": {
      "service": "mdi:volume-high"
    }
  }
}