Many of you have Gateway MA3 / MA7 (MX6xxxx / MT6xxx) notebooks that don't power on at all. Some of you have replaced your jacks, only to find out that the problem remained.
This problem is due to a short in between the layers on your board - but a skilled technician can still repair it. Precision Division in Clearwater FL repairs this problem in the Gateway MA3 / MA7 notebooks. I think they do it for about a hundred, but you'd have to call and check.