[Resolved]  Samsung Monitor Syncmaster 794mg — My monitor giving Hz? problem

Address:

Maharashtra

I having Samsung monitor syncMaster 794MG.I buy it before 3 years ago,but now its giving problem.whenever I going to play games on internet or normally & I upload any videos on internet. then suddenly my monitor shows me Hz? error.I am really panic on it.
I checked all display settings,changed ram,I also format my pc & install with proper display drivers,but problem is still there.whats the solution.when Hz? error shown that time I marked that only power light is showing on CPU & HDD light is totaly closed.
Sir,Pls give me right solution as soon as earlier.

Costumer

Nachiket Oak.