Ninety eight: all lights flashing

Olds ninety eight, year late 1990s. Last night turned the ignition, not even a click. However when jumping all lights inside and out flash systematically. Checked fuse box. Jiggled all electric switches. Verified it was in park. Daughters car, just trying to help. Can turn wrenches but this has me stumped :(.

Thank you.

Welcome to AF. Good grounds and battery connections are important here, also any aftermarket alarm in place?

All stock.

I agree on grounding. I had checked the battery and the frame ground. Thing is this is all systematic. They all flash in synch, they all stop at the same time, it happens when the key is inserted. I tried cleaning the "chip" in the key with alcohol. One swig for me and one for the key ;). When I put a meter on it the battery reads fine, even when cranking (or lack of crank lol).

I am convinced now the chip in the key went bad. She only has one. I am thinking of calling the dealer to see how much they run.

If the key were an issue the dash security lite would stay on.