Hello! I've picked up a cheap 360 Slim on eBay. It has never been opened prior to me getting hold of it. When plugged into a known working adapter, the console will beep when the power button or eject button are pressed. There are no shorts in the USB or AV ports and I have tried a different RF module as I have read that can sometimes cause the problem. There is nothing obvious on the mainboard, no signs of anything have blown that I have noticed, no sign of water damage, no damaged traces. I'm not sure what to check next. Can anyone help point me in the right direction please?