When I use F1 or Photoshop menu Help>Photoshop Online Help... . My default Web Browser start up on this link Photoshop Help | Photoshop Help.
My default Web browser also start up when I use menu Help>Photoshop Support center... on this page Learn Photoshop, get help and support | Adobe Photoshop CC
My default Web browser also start up when I use menu Help>Browas Add-Ons... on this page https://creative.adobe.com/addons?pp=PHSP&ppv=15.1&locale=en
You also failed to note which version of Photoshop and your machine environment.
It may be that there is a problem with you system configuration that executing a URL does not open a web browser.
You wrote it opens but the screen goes black. Can you see what application opes? It should be a web browser or a new tab in a currently running web browser...
You also wrote you enter your Adobe user name and password and get a clock. You failed to state where you entered your Adobe Name and password.
How did you change you password?
The more information you supply about your situation, the better equipped other community members will be to answer. Consider including the following in your question: