DV6 laptop starts from battery but not when plugged in

I have the same problem with HP Pavilion DV6-7138US.

When AC plugged, the notebook don't turns on, blink the caps lock (only one blink with regular time between each) and the HDD LED lights orange. When only with battery, it turns on and works great.

Obs.: I installed a OCZ Vertex 2 60GB on HDD location, and installed the HDD on the DVD bay with a caddy.

Thanks,

Rhuan