The most serious and scary power off!

Question

This is really really scary! My macbook not only shuts down unexpectly, but it also can't power on again!!
I have seen news that people say their macbooks powers off unexpectedly, but initially I didn't encounter such problems. Yesterday afternoon, I found the update that aimed to solve the unexpected shutting down problem and I installed the update. About one hour later, I found I lost my handphone. So I left my macbook on, with Safri, aMSN and external fan running.
I searched every place I had been to, for about an hour but still couldn't find it. Already feeling very irretated, I came back to my macbook. About ten seconds after resuming my work, the screen blinked once and quickly turned black. Very like a power failure. However, my power adapter indicator was green and the battery was fully changed. I tried to turn it on but nothing happened! After several tries, it still doesn't respond! I quickly got the instruction book and tried every possible ways of troubleshooting but still of no use. Oh, don't scare me, apple!
I had sent it to the nearest retail shop for repairing and they said it would be at least one week before they informed me.
Does anyone have any idea what the problem might be? I just switched from Windows and bought this macbook in September. Apple really had me scared. Thank you.
Macbook   Mac OS X (10.4.8)  

Answer 1

So, are you still keeping your macbook?
I would say, normally my macbook runs quite beautifully. You don't get so many irretating warning messages as you do on Windows. But the moment any problem occurs, it's going to cause panic.
Actually, there's more story about my macbook. Within the same week I bought it (in Sep), I had my whole disk erased and OS reinstalled. Guess why?
I downloaded a chatting program, IQQ(from the Lumaqq official website), double clicked the zip file and got my macbook stuck. No matter what I did(click mouse, stroke keyboard), no response, except that the cursor could move around. So I pressed and held the power button, as suggested in the instruction book, to shut it down. Then tried to reboot it. Guess what, it freezed at startup. I tried all the ways of troubleshooting listed in instruction book, attempting to get it restart for more than ten times----failed!
After that, I came to the one--if you have tried all the above steps and the problem still persists, you might have to reinstall your OS(may not be stated exactly like this, but same meaning)-- as you can expect, I spent a whole tiring afternoon reinstalling Mac OS, with all my data lost.
Ever since then, I dare not install any software other than those from apple official website and those that have been installed on other macbooks and proved to be of no problem.