JVC HR-S9800U circuitry, need EEPROM info
 

Does anyone know where in the Service Manual or the Parts List manual, is the EEPROM for this VCR located and what it's corresponding part number is? Would anyone also know as to why changes that were made to the EEPROM, do not stay permanent? (Such as, changes were made, the VCR was then unplugged and left without power overnight, but when plugged back in the next day, all the changes that were made were wiped out)

I don't think I know of any Consumer VCR that retains settings past power removal. EEPROMs have a very limited write cycle and usually require discrete programming device to make changes to. The EEPROM or more likely just ROM isn't able to be altered after manufacture. Changes you make in the settings on a VCR are stored in voltaile memory that looses any changes once the power is removed, unless battery backup has been added some where on the circuit. This is common for something like motherboards, but I don't recall ever seeing a VCR with one. An example of this is needing to reset the time everytime the power is removed. A battery backup would retain the time settings.

Usually when an error is that low down in the components, you have to swap a whole board.