Is my logic board dead
I opened my working late 2012 iMac to exchange hard drive (3TB fusion) against a HGST HE 6TB hard drive and wanted to replace the internal 128GB SSD from the fusion with a SSD Drive Kit and a 1TB SSD 2.5.
So I opened my imac , replaced the ssd with the SATA Blade module, pluged the sata cable in, repositioned everything, replaced the 3TB Seagate with the new HGST 6TB, checked everything and switched it on, but nothing happens. Only the LED 1 and 2 lightened the 3rd and 4th not.
So now I was worried, changed all parts back to the original ones, did the different resets, changed the rams, no difference.
When I switch it on I can hear the disk, the fan, but no chim and no display.
According to all I have read it looks like the logic board is damaged, but there is one thing that makes me hope: when I take off the rams I get the error beeps for having no rams.
Now I am at the end of my ideas. Anything else I can try to check if the logic board is really dead?
Every help is welcome!! Please!
Sorry for my bad English!