Boot problems with older AST w/AC adapter

Archived from groups: comp.sys.laptops (More info?)

Working on an older AST Laptop Ascentia 950N.
It wont boot on occasion when the AC adapter is plugged in.
I checked the adapter which is rated at 18VDC, and its measuring about 18.5
VDC which shouldn't be a problem i would think.
It appears that it may be an electrical issue, and it happens more
frequently when it has been off for a while. It seems that once it heats up
that the problem does not occur. Bad solder joint on the board somewhere
maybe?
Right now i cant get it to happen and 15 mins ago when i first turned it on
it wouldn't boot with the AC adapter in, so i pulled it out and it booted.
Then the screen would go black while tapping on the mouse button, and the
screen was all screwed up as well at other times.
Now with it warmed up i cant get the problem to occur.
Any thoughts would be appreciated.