No power after part replacement
Recently, I had a problem with my Intel iMac (2Ghz - white case - late 2006).
Exactly half of the screen went blank or with vertical lines - the rest of the system was operational and worked perfectly through an external monitor. I managed to source an old G5 with the same screen(same part number from LG) and (using an anti static wrist strap / mat etc.) bravely swapped the screen unit.
My sense of achievement at getting it all back together didn't last long - now it won't even switch on.
The power lead has been checked and with the case off again and the machine plugged in I get 1 LED light (above and to the right of the memory chips (I've tried reseating these)). Also, when I try to switch it on the large circular fan that sits above the power switch tries to turn (sort of twitches) but doesn't spin.
I have read that on older machines there is an internal power switch or even a reset button for the SMU.
Do these buttons exist on my machine (if so where are they)?
Will replacing the watch battery on the logic board help?
I have unplugged the power cord and held the power button for 15 secs (to reset the SMC as described by apple support).
I guess what I am trying to avoid asking is "Have I broken my logic board and do I need to go and buy a new Mac?"
Sorry for the long post - any advice would be gratefully received.