Audio Systems: Car stereo mystery HELP!!, crackling sound, loose ground

Question
Alpine model CDA-D855. Intermittent popping/crackling sound which after a while cuts out sound to speakers completely but there is still power to the head unit{lights on,etc}.It seems when my truck is first started in the morning the stereo works fine but after 15 minutes I start getting the popping and crackling then if i tap on the dashboard it will come back on for 5 minutes and work like this all day untill I loose sound completely.I took the unit out of the dash,power harness still connected and very lightly tapped on the bottom of the unit and got the popping sound to happen,so my guess is it's internal to the stereo itself and not the wiring.Could this be a ground inside? I can't seem to figure out how to take the bottom plate off the unit.Any ideas? {Trying to avoid the 100.00 alpine charges for repair work}Thanks!  

Answer
Jim ,

  if the unit is under warranty definantly send it in .. if its not you might be subject to the stacked alpine charges unless it would pay to by a new unit which is a good option.. more than likly some components have worked lose / work lose ect.. these things happen over time and use , and has caused a short / loose ground ect that cuts your sound and causes distortion .. before you look into the market for a new unit or send this one off .. double check all your wiring on your harness just to make sure all the connections are tight and everything is wrapped good with electric tape so nothing rubs together.. with this said and nothing improves look into sending it in or buying new .. you also might call some local electronics shop that you trust to see if they can take a look and do some repairs might save you some money .. hope this helps you out if you need anything else let me know

thanks