How can I get my DVD HDD Recorder to respond?

I have a Vistron DVD HDD Recorder DHR-5006. The machine stopped responding to all buttons on the remote & front panel after dubbing from HDD to DVD disk. On powering up it goes to "No disk" on the TV screen and there it hangs up. No buttons on the remote or front of machine respond. HDD & DVD drives are working. If a DVD disk is manually put into the drive it loads it and sees it but no responce from controls. the machine did not come with a repair disk. Please help if you can.