How can I fix my Acer Aspire 3682 wxmi?

Can you please help, I can't power up my laptop at all with or without the power lead. The only thing I have changed recently is replaced the memory, however I have used the laptop a few times since, I tried as usual to switch on but it just cut out and now it wont power up at all. I have taken the memory out and tried to power up but still nothing happening. Can you offer any help please.