Chosen Solution
I have 27" iMac mid 2011 which required LCD replacement. I bought another dead iMac to pull lcd and Led inverter board. As soon as I plugged it and blew L9000. iMac stills boots with chime but no display(not surprised) with fans running full speed. Closely inspecting i saw broken data cable for new lcd. So my questions are: 1)Could the bad data connector have caused this? 2) Can bad LCD or LED backlit be cause of this, if yes how to test it? 3) Can I take this connector and take input from somewhere else example solder wires to to 12 v supply from power supply or use other backlight power? 6) Is there any schematic available for the graphics card connector and lcd connectors? Picture of logic board, connector and potential connector attached. The one in picture is in bad shape, other logic board has only L9000 burned out. I will post pictures after cleaning it up.
UPDATED PICTURE
POTENTIAL DONOR
@pbsingh yes schematics are available since it seems like your board is a 820-2828. L9000 is a 250 ohm ferrite bead and it sits on the 12V supply line to the LCD. If you have a donor board, replace the connector. You also want to take a closer looks around C8655 and C8654 there seems to be something going on as well. Check the color of the testpoint. Note that it appears discolored as well. So, getting power from somewhere else may not be your solution. Replace the connector/cable and component and then carefully check your board.
I ended up using a donor board and pulling l4300 out and soldering it to l9000. You cannot take l4300 from the same board. Look on ebay you will find people selling boards for parts. Use that as your donor A potential source could be https://store.rossmanngroup.com/d4-l8300…
