FYI, the old printer didn’t have a scanner. I missed that. So, I returned it and got a new one.
I installed the HP3520 on mswin with no problems. On suse, I installed the HPLIP package on request. I went into Yast-Printers. I did the hp printer setup. Print test page doesn’t work. A print from Firefox doesn’t work either. The HP8100 would print, if I used the cups package driver. So, I need help. What should I do next? Thanks.
Login to the CUPS interface with your web browser
http://localhost:631/
Get to the Administration area (at some point you will be asked login info. User is: root and the password is whatever you used for root)
Delete any printer that might already show and re-add
I find there are a number of similar options. Look for the H3520 CUPS referenced version.
If it works you might want to check the options when printing from Office, because in my experience it can have the old setup and the new, but it defaults to the old.
Deleted current printer
Added USB HP3520
Model added CUPS HP3520
Complete, printer added
HP icon -> printed test page - success 
Thanks, that did the job. It works on office and firefox.
Strange isn’t it
In my experience you will also get better options for things like double side printing