Chosen Solution
Hi everybody here, I just read a lot about diagnostics LEDs here and will give them a try when I have access to my iMac in trouble, again. Maybe, someone can help me out, quickly. After replacement of the HD and powering the iMac on, the fuse of the electric circuit of our basement was tripped. After inserting the fuse again, the iMac started up without any signal on the display (black, no fragments viewable using a flashlight). The iMac works properly with an external display. However, System Preferences -> Displays does only show one display - the external one. I tried another display/video cable-combination of another iMac (same model). This does not work either with the problematic iMac. But the display/video cable-combination of the iMac in trouble works perfectly when it’s installed in the other iMac. The LVDS-connector on the logic board seems to be OK. I haven’t tried to use another inverter board or power supply, yet. I found someone who would solder a new LVDS connector, but it’s quite expensive. Shall I give it a try? What do you think? Best regards
The logic board needed repair: inductor L9000 was burned:
This is a detail of the circuit diagram:
When the inductor was replaced, the internal screen started working again. Hooray! Some had trouble to locate the inductor. Here is an image that should be helpful:
Use a flashlight held at an angle to the screen (with the machine booted up), and see if you can discern the desktop. We’re checking out the LED driver board. If the desktop is there we then want to make sure of your exact model A, to get you to the correct part and guide, B. To make sure it’s not a bit of an older machine with an inverter.
Hi, here is the link for the circuit I used to solve the problem: https://www.digikey.com/product-detail/e…
that did the job!! Tks for sharing!
Thanks for this post! I have same issue iMAC, A1311, where could I purchase inductor L9000?