Not sure which things you've tried, other than disconnecting the battery. There
are contacts that signal the computer that the door is open/closed. There is an
array of them on the door that match to those on the door jamb. They are spring
loaded, so if they don't move freely, they will cause the condition you have.
Some say to clean the contacts with a pencil eraser. It is also recommended
that you use a silicone based lubricating spray because they don't oxidize, dry
out, and lose lubricity.
On the door side the contacts are spring loaded inside a plastic sleeve and the
sleeve is spring loaded too so be sure to lubricate both surfaces on each
contact. On the jamb, there is only the sleeve to lubricate. Lubricate liberally with
a high quality silicone spray.
2 people found this helpful.