Default Phone will not turn on?

Hi to start off i went to bed last night and put my phone on charge (with w zero lemon battery) the same thing I have done loads of times before, and woke up to the phone not responding it had the charge led on and that was it, so i removed the battery and replaced it. Now my phone will not turn on i cant get the charge light to show up, i have tried 2 other batterys I have, one is the stock. All i get is the proximity sensor led flashes every 10 seconds, it will also do this if i have no battery but its plugged in. i have tried draining the capacitor by leaving it with no battery and no charger for 30 mins still no difference, I have tried different cables.

i had the latest CWR and was running MIUI
it hasn't taken and falls or anything just recently

could this have something to do with the OTA update?
I was reading about the SDS (Sudden Death Syndrome) could it be this? i hadn't heard anything about this before, is there a fix?

I don't mind opening it up and i am quite handy with electronics and a soldering iron if there is a need/way to hard flash the phone.
any help is appreciated