General Question

I bought a used 1995 Chevy Blazer S-10. Approx. 172,000 miles, V6. It started before I bought it. Now it won't start. My mechanic had narrowed it down to the computer. He ordered a brand new one. When it arrived he found that the Chevy dealer has to install it because it comes blank and they have to program it. So he had it towed to the local Chevy dealer who installed the new computer. The computer which is brand new and has never been on a vehicle which has fired, including the Blazer it was just installed on, is now running codes, one of which is saying that the ignition module is bad. Is this true that a computer which is brand new can have codes on a vehicle that it hasn't been fired on? Thank you for any help.