I have a 2013 f150 with the basic oem 4.2 screen Connected to a lc2i. The lc2i is connected to a jbl mono amp running a single 10 sub. This was professionally installed about three years ago and has been fine up until the last month. I can usually play music for about 20 minutes or so full volume while driving and then the music and bass cuts out at times. The amp feels cool to the touch. What should I be troubleshooting before having to take it to a professional?