Yes, mouse tracking speed and speaker volume settings are kept in the PRAM.
Before any further attempt to fix something you might consider to double check for proper polarity of the battery and also check if the battery is full. If the battery is of appropriate type, correctly inserted and full, most likely the battery connection is damaged somewhere.
As for the schematics I can not help, some other comrade might kindly assist. The off-load voltage of a battery might be a weak indicator of the charge condition. A suggestion to properly check the condition of a PRAM-battery would be welcome, too. Information about lithium batteries in general can be found on Wikipedia: Lithium battery, of course.
Before any further attempt to fix something you might consider to double check for proper polarity of the battery and also check if the battery is full. If the battery is of appropriate type, correctly inserted and full, most likely the battery connection is damaged somewhere.
As for the schematics I can not help, some other comrade might kindly assist. The off-load voltage of a battery might be a weak indicator of the charge condition. A suggestion to properly check the condition of a PRAM-battery would be welcome, too. Information about lithium batteries in general can be found on Wikipedia: Lithium battery, of course.