Cassete willl not eject

hi, your camera may needs a good head cleaning,

hope that will help..
regards Alan

My advice is that you should by a DV cleaning cassette. Put this in the camera and run it for 10 to 20 seconds only. running the cleaning cassette for a long time may damage the head.
good luck!
Luwangula

The DAT machine needs new belts and maybe some cleaning. These fail all the time due to old belts that lose the tension that is required.

This is a tape transport problem and is expensive to fix. Unless you know a cheap tech, it's time for a new one. Be patient loading and unloading tapes. This is usually what causes this problem. The Yellow warning sticker is REALLY important. Another important item is to always use the same brand of tape because switching tapes causes a gummy build-up the makes tapes get caught in the machine.
Videoteacher

http://www.tradebit.com/filedetail.php/4993163-canon-mv790-mv800-mv800i-mv830-mv830i-and

Official service manual for the MV850i

Here you go..
http://drivers.softpedia.com/get/Other-DRIVERS-TOOLS/Others/Canon-DV-camera-MV850i-650.shtml

Solutions * The most frequent cause of this type situation is not having a power source attached, or a depleted battery pack. * Once the power source is available, some models require manually unlatching and opening a cover. * When the cover is fully open, the cassette will eject automatically after a few seconds. * If the tape still will not eject, seek assistance from a Service Facility because you need a special tool to remove the tape without causing further damage.

Here is a link to the driver that you are looking for: http://software.canon-europe.com/products/0010195.asp Hope this works for you:)

Recently repaired one of these with what appeared to be a power supply problem; found several defective capacitors on the drive board. The symptoms were similar to what you are seeing.