Does not power up but Firewire 800 port wakes up
My iMac Intel 24" EMC 2134 (Mid 2007) had not been able to power on for a couple of years. I mean completely dead, no chime sound, nothing when the power button is pressed. I recently bought a matching power supply from Amazon and replaced the old one per the instructions on this forum. It still does not power on, but an external 1 TB hard drive connected to the back of the iMac via the FireWire 800 port wakes up if and only if the iMac's power cord is connected to the wall power outlet. If I pull the iMac's power cord from the wall, the external hard drive would shut off after 10 seconds or so. If I plug the iMac's power cord back into the wall power outlet, the external hard drive once again wakes up . (By "wake up" I mean the external hard drive's blue LED turns on and you can hear the drive rev up and remain spinning.)
What can you say about the iMac's power supply given this behavior? Is it "working" but some other component is not? Is the external hard drive supposed to wake up when the iMac's power cord is connected to the wall even if the iMac's power supply itself is completely dead? Any conclusions and suggestions?
I checked the LEDs. When the power cord is connected, LED1 remains on. When I then press the power-on button at the back of the iMac, LED2 blinks for a split second while the fan tries to rotate for a bit but then stops. See attached pic and video.
Is this a good question?