Home Theater Questions? Ask a Technician for Answers ASAP
Hi and welcome to JustAnswer,Thank you for the question and your patience. Should you still need assistance for information purposes only...Initially, the described symptom almost always is an internal hardware issue. As it is mechanical, the diagnosis would rely mostly on visual inspection.
Would an illustrated repair/Service Manual in electronic form serve your purpose then?
There would be a token fee for this manual. Of particular interest would be the exploded parts diagram to serve as reference on the dis-assembly, parts checking and re-assembly.