Dell numbered diagnostic leds

What model do you have? I have a XPS400 and 1&3 is a memory error.

Just google dell diagnostic lights with the model number and it should tell you the codes. I have a Dell XPS 400 and When I searched for the lights I found it in the troubleshooting documentation.

Here is the link for the XPS 400.
http://support.dell.com/support/edocs/systems/xps400/sm...

Dell may use the same codes for all computer But I am not sure.

Hope this helps

Best answer selected by technocretin.

both answers were helpful and it was the memory module that had come unseated, now works fine

thanks to both

Technocretin