Dell inspiron 15 7000 Gaming - problem standby mode

Dear Readers,

I've been having some trouble with my newly bought laptop. I have been using it for about 2 months (daily) and recently a problem has occurred. Namely, when my laptop goes in standby mode, and I turn it on, the screen shows colored/grey stripes.

I have already looked if it did the same when in the BIOS, this showed nothing strange. Also, when I attached my laptop to another screen during the occurring problem, it showed the normal screen on the external screen and I could execute everything.

I would appreciate a little help with this problem. Please let me know if you have any solution in mind.