Video Playback / Recording Devices

Just recently, our JVC DR-MV5S dvd video recorder with vcr recorder will play dvd and vcr but with no audio. I checked connections and setup screens, I checked JVC web site looking for technical support. I found some dvd reset codes on JVC's web site but none related to my model. I tried those reset procedures and none worked. I rebooted/recycled the DVD player at least a dozen times. Any clue on what to try next?
Thanks in advance for your assistance.

Lost instructions, have a Emerson DVD VHS combo, Zenith TV. Need to record & watch TV program and recrod while watching other channel. Any advice would be appreciated.

I have a Pioneer dvd burner 106d installed in my p.c. i have been converting my vhs movie collection to dvd,through nero express with success,but as of yesterday it wont burn to disc.i go'es through the process up to burning to disc.then i get message saying burn failed? i have tried it a few times,but to no avail.the dvd seems to play discs ok.just wont burn.should i scrap and get a new one or any other ideas! thanks.davo99