If you can sign in to the DPS dashboard, you should be able to sign in via folio builder panel as well. What happens when you try to sign in? Error message?
About the DPS dashboard option, unfortunately we are currently experiencing intermittent issues, more details here http://status.adobedps.com/?p=662
Workaround to access folio producer and admin panel is to open the following link in a new tab once logged in to the dashboard
- Admin panel: https://digitalpublishing.acrobat.com/app.html#x=admin
- Folio producer: Adobe Digital Publishing Suite