Hmmmm…. how do the LEDs light up if the computer isn’t plugged in? perhaps there’s another guide? How to read the LED’s
I managed to damage mine also .. but, it was probably already damaged by Apple when they replaced a recall hard drive. I managed to fix it like Wojtek. had to re-solder tabs to the logic board. Would like to find a dead logic board and de-solder the connector for a spare; however, I think all the little pins fall out if you try that … SIGH!