What model Gateway is the machine? On some models, the system will work fine if the battery is dead/not-installed as long it is connected to power through the A/C adapter.

Good Evening and welcome to Daniweb!

Have you tried an ATX reset by any chance? As that will usually solve most power related issues.

Dazza

What's an ATX reset and how do you do that?

Did you find a solution to this?

Thankx! You da man. That seems to have fixed my problem from another thread. ATX reset. Who knew?

Grrrr. spoke too soon. MAchine booted normally a couple of times, then did the same thing again.

What's an atx reset and how do i do that?

ATX Reset explained - and shamelessly stolen from Packard Bell's website!

Instructions for Performing the Power Discharge Procedure (ATX Reset)

Information:
Your computer or monitor has no power at all or cannot boot properly. In some situations this can be caused by an external device or an electrical problem. This can usually be solved by removing all external devices and resetting the power supply.

Instructions for desktops:

1. Disconnect all external devices you have, including the keyboard and the mouse.
2. Unplug the power cord.
3. Press the power button and hold it for at least 15 seconds.
4. Reconnect the power cord. If your computer is a desktop, please make sure the wall socket you are using is grounded.
Do not yet reconnect the external devices, they should stay disconnected.
5. Switch on your computer and test if it boots normally.

Instructions for notebooks:

1. Disconnect all external devices you have.
2. Unplug the power adapter from the notebook.
3. Remove the battery from the notebook (if possible).
4. Press the power button and hold it for at least 15 seconds.
5. Reconnect the power adapter.
Do not yet reconnect the external devices, they should stay disconnected. Do not yet reseat the battery.
6. Switch your computer on and test if it boots normally and watch if the power LED lights up.
7. If the power LED still does not lights up, continue with the next steps.
8. Disconnect the power adapter from the notebook.
9. Press the power button and hold it for at least 15 seconds.
10. Reseat the battery. Do not reconnect the power adapter.
11. Switch your computer on and test if it boots normally.

Instructions for monitors:

1. Disconnect the monitor from the computer
2. Unplug the power cord.
3. Press the power button and hold it for at least 15 seconds.
4. Reconnect the power cord and connect the monitor to the computer. Please make sure the wall socket you are using is grounded.
5. Switch on the monitor and check if monitor works fine again.

awesome thanks a ton, i will try it tonight and let you know!