MX8710 Wont power up

Was using the notebook (plugged in to wall) when i noticed that the screen was intermittently going dim (dont know if all gateways do this but mine does it when its on battery power, then the screen goes bright when its being charged).

After a period of time it wasnt charging at all. I grabbed the power cable and was moving it around and got it to start charging when i moved the cable just right. By this time the battery was almost dead so I shut it down and assumed I had a faulty cable. The DC connection at the back of the notebook isnt loose and its a nice snug fit when the cable is inserted. I ordered a new power cable and still no worky. When you push the power button, all that happens is the red battery light flashes 4 times.

I disassembled the entire laptop looking for loose solders or anything out of the ordinary and couldnt find anything, even at the DC connection. I removed and re-installed the hard drive, the ram chips, and the battery and it still wont power up.

I noticed a small watch type battery on the motherboard...I assume this is to keep a small amount of memory in case the main battery goes completely dead??? Is there any checks I can make that will narrow it down to the exact problem? I hoping its not the motherboard but with my luck Im guessing thats what the problem will be.

Any help is much appreciated!

Josh

Is there a way I can make voltage checks on the motherboard to be sure that its the jack? The jack has 5 pins soldered to the board....does anyone have a schematic as to which pins should have power when its plugged in?

I will double check the voltage coming out of the new power cable as well as the old one.

Well I had the motherboard by itself setting on my desk with only the essentials plugged in and it powered up. The only thing I did was re-seat the ram this time. I also tried my old cable and it wouldnt work so I wonder if I had a combination of poorly seated RAM and a faulty power cable. Who knows, it works now. Thanks for the tips.