Chosen Solution
Hi everyone! I’ve got a late 2007 iMac intel 2134 that won’t power up at all. I confirmed that the AC cord is working, and then checked the LEDs, but none of them are on. At this point I’m fairly sure the problem is the Power Supply Unit. I have currently removed the PSU. So here’s my question: is there any way for me (very little electrical experience) to test the PSU to make sure it’s faulty before ordering another $140 part? Also, how can I check the connection between the AC input and the PSU? Thanks!
You could use an Ohm meter to test continuity between the blades of the AC outlet on the back thru to the connector on the PSU. I would strongly not try to test this live (AC)! It sounds like you have isolated this down correctly to the PSU. I would also point out you could have gotten an electrical spike (lightning) which killed it. Make sure you have a good surge suppressor outlet strip and/or a UPS for the system and your accessories are plugged into.
