Is your internal PC speaker connected? If it is, are there beep codes? (example: 1 long beep, 1 short beep)
Maraming posibleng problema. Yep, RAM is one. Processor + Mobo can be another. Still, it could be as simple as a faulty display connection.
To rule out the display device as a problem, try toggling the Numlock/Capslock LEDs through the keyboard. If it doesn't comply, then your problem is either the Proccie, Mobo, or RAM.
As for prevention pala..
-Never skimp on the Power Supply. Generic ones (apart from not having enough wattage or ampere ratings on the rails) can cause fluctuations in power distributed to the components.
-Avoid generic RAM. Spend the extra 200-300 pesos and get the cheapest Transcend/Kingston/PQI. Plus, the latter's warranty is probably longer.
-Get a decent cooling solution. It doesn't have to be water-cooling. You don't have to buy fancy copper heatsinks with pipes. Simply purchasing a fan for front intakes and rear ones for exhaust will go a long way. To further cool your CPU by 10'C or so, borrow some branded thermal compound (Arctic Silver, MT2, etc) from a friend and replace the stock thermal paste on your CPU with this.
