Q: MacBook Not staying on for longer than 5-15 seconds (Mid-2009 White, 2.13ghz)

So today i received a refurbished MacBook, White, from Mid-2009. Everything was going great, until the end of the welcome video (Running Snow Leopard). At this point the computer crashed, and had to be turned off, and then back on. When turned back on, it started from where it left off. After about 5-15 seconds, it did the same thing. I got through the setup process VERY SLOWLY, but I still did. I am still having the issue, and the time is still 5-15 seconds. I do have a warranty with the website I bought it from, and before I send it (If I have to), I want to see if there is any fix I myself can do to fix this issue! Thanks for reading!