With faulty gas valve solenoids their really ain't no way to check em with a meter. If your gas dryer has a good flame sensor and a good igniter AND the dryer will work some and quit, replace these:
Gas operator coils
part# 279834
Replacing them is easy. All you need is a phillips head screwdriver. Make sure the quick connects are tight. And do not touch
the ignitor when doing this operation: