Hi. My name is Rick. I'm a camera repair technician with over 20 years in the business and I'll be glad to help you with your question today, but I'll need a little more information first.
You say the tape mechanism rises but will not open. Does it retract back into the camcorder?
Yes, it retracts within 6 seconds without my doing anything.
It sounds like there may be some obstruction preventing the carriage from reaching the top. There is a mechanical trigger to release the cassette compartment which, if not broken, automatically opens when the carriage rises fully. To be honest with you, It's going to need to be looked at by a technician. It is repairable but it is complicated. This is a job for someone who does this for a living. Below is a link to a directory of repair shops, one of which should be in your area and able to help you.