Me again,
i managed to find the issue that caused my problem. Just in case anyone wants to know: I accidentially broke on pin on the cpu socket that connencts to the ram slots "A". I just installed the Ram in the B slots and everything works fine again. Thanks for your support.

Re: iMac 27" Retina 5K i5 3.2Ghz no chime, no display, LED 1 and 2 on

Sorry i overread the question about why i removed the cpu..
Its just like i´ve never seen a cpu socket without any tool to hold the cpu in place. I did it many times and there is always a lever or something like that to push the cpu to the socket. In case of the IMac logicboard there is nothing like that, so when i pulled up the heatspreader the cpu comes with it and dropped after like an inch or so... Aplle Hardware is new to me. I will never do the same mistake again...

Re: iMac 27" Retina 5K i5 3.2Ghz no chime, no display, LED 1 and 2 on

Hey,
thank you for your reply. You´re absolutely right! I studyed the schematics and boardview i got from another post and found out that the broken pin was for RAM Slots "A" . (exactly it was the 6th one from the right side of the socket if you look at it with Ram slots facing downwards)
I then removed the Ram sticks and tryed the "B" slots and the Imac started posting again . I heard the chime and after refitting the Panel everything worked.
It´s sad that i...

Good evening guys, im new to this forum and searched around it to find a way to fix my broken imac 27 retina late 2015. Logic Board is 820-00292-A
Here´s the problem :
After i changed the blade ssd with an NVME SSD and accidentially bent some cpu socket pins (managed to get them straight up again, one pin broke but seems to be N/C) while trying to get some fresh thermal paste, i hear no chime and have no display. LEDs 1 and 2 are green but 3 and 4 not. I did some measuring and it seems that gfx_ok, is ok but dp_ok, is not okay. Checked some caps and diodes in circuit but everything...

Re: 820-00291-A schematic & BRD files

First of all thank you very much!
Im new to the crew and no expert in electronics repar but have a sense for it and technical background knowledge. Im from Germany so please excuse my english.If you have any questions, go for it!
I wanted to ask you guys for help with my Imac .
Is there any possibility to get brd file and schematics for 820-00291-a?
I upgraded my late 2015 imac 27" Retina 5K i5 3.2Ghz with 16gb ram and a 1tb nvme ssd recently. After i re-assembled it i got no start chime and no display!...