Hi and welcome to JustAnswer,Thank you for the question and your patience. Should you still need assistance for information purposes only...Initially, bear with us; re-confirm and post back with the complete model number of the camcorder.
Appreciate the additional information.
Even if "...will not record...", will it allow playback?
Has the JVC GR-D371U been in fairly constant use and this issue recent? ...or has the unit been in storage and upon trying, this is the result?
Possibilities are an internal hardware concern such as an issue with a motor or dew sensor acting up.
Have you tried leaving the JVC in the cassette EJECT position to allow air to circulate freely? This is the only easy user doable try as all others would require dis-assembly.
Please post back results / observations of the above once tried.