Chosen Solution
I’m one of Japanese guy so sorry for my bad english I repaired my Imac, but it doesn’t start. As for the power supply, I tryed two other things and verified it, so I think the reason is the logic board. I tryed to short the power button cable to boot, but it didn’t work. It did not work even if I heated the logic board with a heat gun, but LED1 is operating without problems, it seems that it is stuck at startup after pressing the power button. Is it necessary to replace the logic board? I would like to confirm the continuity, but I do not know where to check, so please give me an suggestion
システムがまったく起動しない（表示画面が点灯しない）場合は、電源装置に問題がある可能性があります。 優れたサージサプレッサ、またはUPSとそれに接続されているすべての周辺機器とシステムがありますか？ 保護されていない場合、落雷やサージによってシステムが停止する可能性があります。 If the system does not startup at all (display screen is never lit) you likely have a bad power supply. Do you have a good surge suppressor or better yet a UPS and all of the peripherals and your system plugged into it? A lightning hit or surge can kill your system if not protected.
