This microwave has a touchpad display and the customer was complaining that the display was blank and microwave wouldnt heat. They also said they saw an f7 error. So when I went out the display was blank and so I unplugged it and plugged it back in and the display came on and the microwave wasn't heating. I am at a lose on what to order the lcd display, control board, or inverter board either way it seems like I am throwing parts at it. According to the f7 error it says to start with the inverter board I was just wondering if anyone had any suggestions on what to replace first.