Had a 40gb YLOD system in today,
did the fix and the console powered up fine, fan stayed normal but no image on the screen on either HDMI or Composite, so i tried the usual safe mode option 3 and wont even go into safe mode, beeps to turn on hold button 1 beep continue holding 2 beeps then powers off, safe again except release after 2nd beep and still NO SIGNAL appears on the Tv, when it first starts up it says Searching for Signals then goes to NO SIGNAL so i thought it was resolution but i cant get it into safe mode to try, i've tried starting without the HDD but still no good so i've come to a dead end
I always use the gilksy guide that i learnt ages ago but this is the first time ive come across this outcome!
From the sound of things you've done this multiple times which would indicate that several of the crucial components within the PS3 have been frazzled from this. It's probably damaged beyond repair at this point. Sorry.
The fact it has been opened and dismantled means that no store will want to touch it with a bargepole and you'd be best off selling things like the BluRay drive on eBay, and putting the money towards a new console.
Really... The gilksy method has seen my consoles lasts 2 years at a time before needing attention again...
From what I've read, and from that video it sounds as though a chip has given up the ghost. It's even more likely if it's been done more than once.