Epson does not publish a service manual that is for sell. They will not supply parts to non Epson authorized service reps.
These cameras are service by module substitution. Calibration is done with a calibration system, jigs, and software. The calibration parameters is then writen to the EPROM.
The service manual that the service reps get is not a detailed component level manual. There are only some things that are serviced at the component level, such as some types of switches, and connectors. The manual that they give out to their service reps is mostly pictorial, and describes the module replacments, and how to do the calibration with their factory setup.
If you call Epson, I think they service these at a base flat rate, plus the parts. Depending on the fault, your camera may not be too expensive to service. You should call their support line to find out what is involved.
There is a chance that the I/O to the memory card is not working properly, or the socket is defective, and that is why the pictures are not stored, and yet they are visible in the viewfinder. I would also suggest to format the memroy card, or to try another memory card, before sending the camera for service. I have seen defective memory cards cause your description.
Jerry G. ======