Screen flickers and jangle sound. Ram problem?

[Blitz Blitz]

Hi, I bought used ram 4 gb, and added to my laptop, well I feel better performance, but after using some hours, I saw screen flickers and heard jangle sound. I don't have any problems before. Rams have identical numbers, speeds, mhz and etc. but one I bought is older about year. Any solutions, test, compatibility check, etc.? Maybe windows reinstall can help?

 

[Lutfij]

For tests, run memtest86 for 10 passes and if any errors come up then the ram(s) is(are) faulty. I am curious though, did you add a single stick of 4GB to your existing configuration? What was your ram prior to the upgrade? Can you also include specs for the ram you had prior and after the upgrade? It'll also help if you can include your laptop's make and model number. Are you sure your BIOS is up to date? What of your OS?