2001 Blazer won't start

I don't even know where to begin with this. My 2001 Blazer (178K miles) won't start. When the key is turned, all the lights on the dash flash repeatedly (incl. the 4WD switch), and finally "ERR" is displayed on the radio. Battery has a good charge. Starter doesn't even try. My husband says that while all the flashing is happening, he can hear all sorts of other things switching on and off (like the rear wiper motor). I suspect a computer problem... suggestions?

How do you know the battery has a good charge?

Have you owned this since new?

Have you checked the battery connections?

The battery connections are fine (checked those).

The voltage indicator on the dash is showing the proper voltage, and my husband tested the battery separately.

The battery-driven stuff works just fine.

I've owned this Blazer since 2004. I'm the second owner, purchased it with about 50K miles on it.

This whole thing was very odd. He drove the Blazer the prior evening, and it was fine. The next morning, when he tried to start it, he got the light show, the ERR message on the radio display, and no start.

sorry wrong post. I have a 01 blazer problem too. lol!