Are you sure the problem is not with the screen? Check all connections. ''<p>88kavaler [[#question-1350280|said]]</p>'' <blockquote>The page shakes vertically when it downloading. </blockquote> Just during downloading? Is this with all websites/pages, some, a few? [https://support&#46;mozilla&#46;org/en-US/kb/diagnose-firefox-issues-using-troubleshoot-mode Start Firefox using Troubleshoot(Safe) Mode] {web link} A small dialog should appear&#46; Click '''Start In Troubleshoot(Safe) Mode''' (not Refresh)&#46; Is the problem still there?