Postagem original de: Owen Cunneely ,
You might check to see if the video/graphics card in the iMac is not fully seated. This would cause no display on the internal and external displays. I do not think that the display panel would be damaged but the glue might have done something that affected the panel in some way which seems very unlikely. I would see if the video card is loose. I once got dust between the graphics card and the slot and it caused it to have graphical errors. You might also want to clean the graphics card contacts and slot with compressed air.