iMac Rev A Black Screen

[Copeland]

Bought one and it fires up, LED glows, but the screen does not turn on.

After about a minute, the fans kick in on high speed.

I've searched, but cant find an answer.

Also tried to the reset by holding down option, command, p +r

 

[Muncher]

Take it in?

 

[Copeland]

Take it in?

I doubt a 4 year old machine is still in warranty. Trying to fix myself

 

[Muncher]

Aha, I thought you meant Rev. A aluminum iMac. Perhaps there is a short on your logic board? The screen does not turn on, but a temp. sensor senses dangerous heat levels, so all fans come on. If that's the truth, there's little you can do to fix it. Even if you open it up and find whatever went wrong, the affected parts would likely be damaged.