Years ago I purchased a DJI Osmo original thru DJI's website,  If I recall correctly.
After at least 2 years of non-use, it no longer responds to some input from the controls.
My question is what it would cost to repair or overhaul.

not sure. it depends on what needs to be fixed. You can send it in to dji and they will give you a quote.

Sorry to hear about that. May you kindly tell us which Osmo you referred to? May we know if it still responds when charging it? You may however send it back to our facility for a thorough diagnosis by our certified technicians. Surely, you will receive a notification regarding the repair quotation and other important details. If decided, please fill out our Request Repair Service online. If you encounter difficulties, you may also contact our Product Support team to help you with arranging/creating a case regarding the matter. Hope this helps.

My DJI osmo is version 1. It The charging indicaters show fully charged.
Thank you.

Thank you for your response. You're welcome. If you need further assistance, please don't hesitate to let us know and we will be more than happy to further assist you. Rest assured that this will be taken care of and handled accordingly. Thank you for your support and have a nice day!