Chosen Solution
Hi folks, I’ve had my 2308 iMac since new. It was working just fine, and then one day I came to switch it on and got the chime, but nothing else. Blank screen, no response, etc. I have attempted to reset the PRAM/SMC with wireless and wired keyboards, and tried to boot in Recovery mode: nothing. I also hooked up an external display: again, nothing. Having looked though the vents on the bottom, I can see two diagnostic LEDs lit (as this model has integrated graphics, I’m assuming there should be three lit?) Any ideas? If it helps, service history: about 4 years ago, I replaced the original Seagate drive (broken). Everything seemed to work fine after that, although the optical drive stopped reading discs.
If you do see the faint image of your desktop and icons that tells us the displays backlight has failed. Most likely the LED Driver Board needs replacing ‘‘iMac Intel 21.5" EMC 2308 LED Driver Board Replacement
