PS3 Slim YLOD HELP!! Possible BRICK???

Hi,

So I have a problem. I have a ps3 120gb slim model CECH-2002A which was using Rogero CFW.
I wanted to put TrueBlue CFW to use with my TB dongle. Knowing I had to put OFW 3.55 back on first, and then update I proceeded to do this.

I put the slim into Recovery Mode, started the update process that way and let it do it's thing. Now I'm not 100% sure if this completed all the way, but as you know when you've finished installing firmware the unit is supposed to restart.
Well mine had just switched off.

I thought that was strange so I turned the unit on manually, then i get 3 beeps and my console is flashing red, resulting in RLOD. I thought this was really strange as I had used the same OFW pup file before on my 60gb model no problem.
I unplugged EVERYTHING from the console and left it overnight. Next morning I tried to power up the unit again.. green light.. on for 5, 6 seconds or so, this time flash of yellow then 3 beeps, then flashing red resulting in the dreaded YLOD.
Now I know for sure this is NOT an overheating issue, it has a fan mod installed and the CPU temperature is only between 40 - 44c, no way to cause YLOD from an overheating issue.
I have also tried a different hdd, still ylod. I have also tried booting up the console without a hdd inserted, and stil get the same result.
I have been doing alot of reading on the net, and I have found something about inserting a downgrade dongle, then pressing the power and eject buttons quickly will get the ps3 to boot in to Factory Service Mode and being able to reinstall firmware from there.
Has anyone heard about this?

I'm thinking it's definitely from a bad flash, but because of of the ylod, the console doesn't stay on long enough for me to get into recovery or safe mode.
So my question is am i dealing with a potential brick here? Any input or advice would be greatly appreciated. I would love to solve this!
Cheers