Chosen Solution
Hay I have a MacBook (13-inch, aluminum, late 2008). If i turn it on, i hear the start sound but the screen stays black.An external monitor also does not work.I tried to reset the NVRAM/PRAM and its still not working Any Ideas?
Do you see a slight glow of the display in a darkened room? If you do your logic board needs repairs or replacement.
I had this problem a while ago with a clients computer. After trying the usual troubleshooting by resetting PRAM etc. I took off the back to discover that there was massive corrosion on the powerboard and that the moisture indicator had turned red. After cleaning the electronics with Isopropanol, which will dry out moisture and also remove most corrosion, and removing the battery the computer started but ran very slowly. After also replacing the battery with a new one the system returned to normal
