Normally just the fact the ignitor glows is a sign they are closed. But you can check the little dimesized switches around the burner box to see if the tiny button in the center is tripped. And you can als use a short wire to bypass the switches, or pull the 2 wires off each and touch them together. Do not touch the cabinet though with the 24 v wire .
You can buy online or from any Carrier, Bryant or Payne dealer. Here is the replacement board so you can shop around.