Question edited for clarity, 'make model (what it is)'.
Question moved from Computers to model category.
If the text is garbled and the sound is bad, it won't be mechanical and needs compressed air. It is likely to be failing Electrolytic Capacitors. Take it to an audio technician but first try a CD cleaning disc as a long-shot. They have little brushes that clean the laser optics.
You are the only person to report this issue.
https://www.google.com/search?q=VocoPro+DVX-890K+garbled+screen
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here is the repair manual good luck!! it will explain to you what procedures you need to do to see if you either can get it running or call a qualified professional to repair it !!
http://appliancejunk.com/forums/index.php?action=downloads