Hello tech guys out there! I am having this issue with my Compaq Presario R4000. Whenever I have been using my laptop for more than 15-20 min, the ac adapter will not charge propertly. I will keep blinking on the power light as well as the start buttton light. But if I were to turn off the laptop and plug in the AC, it will charge normally again. Any idea what would be causing this issue? I am thinking it could be motherboard issue that controls the charging but it is really wierd. Anyone had this issue before, please share with me how you resolve it? It might also be the DC port..... Any comments or suggestion would be appreciated. BTW, I am also looking for 2gb ram PC 2700 for my laptop. If anyone has these for sale, please email me at email@example.com Thanks!