I recently replaced screen on my MI4 and everything is working well except the lighting on capacitive buttons. Firstly, menu button was lighting weaker and now it doesn't work at all on all 3 buttons. Button light option is enabled in settings. I have read somewhere that it is controlled by bottom flex cable which I also had replaced because during the lcd change they accidentaly cut the flex cable in service. Also, reception is not the best now and as I see from the pictures it is attached to the same flex. Searching the internet, i found 2 types of flex cables, one which has written LTE-TD on it and another one which has writtens something starting with W. I have MI 4LTE-CU, atleast that is written in settings under model number. Would changing the flex cable again solve my problems and if so which one should I get?