I have a Panasonic DMR-EZ48V and have had many problems with it from day one. It sometimes records a tv program sometimes not. Sometimes plays dvd movies sometimes not. It often freezes up and has to be unplugged and plugged back in to get it to release dvds turn off turn on...etc. The engineer at panasonic said that he is 99.9% sure that the only problem is that I do not have cable tv. If I had cable the unit would work fine. Have you found this to be true?

SOURCE: I have a Panasonic DMR-EZ48V and have had many

sounds like total hogwash to me. Your description of the problem smacks of an internal error within the unit itself.
this is not exaustive but could lend itself to a buggy firmware upgrade or a noisy power supply problem which is causing the microprocessor to "Hang".
There is many forums including this one with the same lament as yours. It is widely known that power supplies in the panasonics are under engineered and have a tendency to overheat and cause many problems including rebooting, constantly "self checking", etc.
My suggestion is to take the unit to another "accredited' Panasonic Service agent and get a second opinion - Good Luck

SOURCE: where can i find a manual for my Panasonic DMR-EZ48V recorder?

You can download the user manual for this unit from this links.

http://www.panasonic.com.au/products/details.cfm?objectID=4291

http://www.devicemanuals.com/guide/DVD/Panasonic/Panasonic-DMR-EZ48V-DVD-Operation-Manual-==TWpZMU5EWXc=.html