Hate to ruin the fun, but I think I know what was wrong.
Newer Eggo IIs are shipping with a plastic spacer panel that is meant to be inserted between the two batteries. Some manufacturers make their batteries smaller than others, so that the fit in the Eggo's battery compartment is not snug. This causes the batteries to lose contact with the erm, contacts.
That will cause the symptoms you describe.
Newer Eggo IIs are shipping with a plastic spacer panel that is meant to be inserted between the two batteries. Some manufacturers make their batteries smaller than others, so that the fit in the Eggo's battery compartment is not snug. This causes the batteries to lose contact with the erm, contacts.
That will cause the symptoms you describe.