回答“Why won't my iMac turn on?”I just wanted to concur. I had the same symptoms, led 1 on when plugged in. When power button pressed, I would only here the disc drive make a sound and nothing else. No fans, no HD, no monitor, no chime. The LEDs would light up on 1, 2, and 3. I removed the power supply and noticed one of the capacitors was bulging on the top. One of the chips seemed to be slightly charred on the other side. For my 24 inch a1225 emc 2211 I ordered a refurbished power supply from eBay for $140. The part number was PA-3241-02A1. I reinstalled and it booted right up. I used some duct tape to lift the glass off the computer sinc I didn't have suction cups. Just took a piece and placed it near the top and careful tugged on it till the glass released.