Hi, my computer's green power light keeps on blinking whenever I plug the power in and it won't turn on, but when I took it to the repair shop the repairman plugged it in and it booted fine. Then when I took it back home and plugged it in again the green light blinks and it won't turn on, so I took the computer to all the outlets in the house and plugged it in and it won't turn on, what do I do now?

Does your computer have access to earth? Might be something wrong with the power supply in your home.
Try to bring a friend's computer over and see if it is able to turn on.

Some computers have the ability to check input power for proper input. Take the PC to another location (not in the same building) & try it. If it works there, the AC power in your building may have a problem which would only affect some PC's. If it does work there either, ignore the power issue.
Another situation is the sleep or hibernate capability provided on some PC's. Waking these PC's when the light is blinking may require pressing & holding the power button until you see activity (typically 5-10 secs).