Where did you palace the puppy pads? Dogs do not love to do their business in the place they sleep. My Yorkie can go potty on the pads in the bathroom when I leave home as well as in the yard. Peeing inside or outside need different training, which should be started from the puppyhood. Yorkies are very smart and good at learning, you share two different potty training methods in the links:
1.
Potty training outside
2.
Indoor pee-pad training
Hope these could help you!