well the original problem started when stuck on firmware 3.6, when upgrading harddrive I got Data is corrupted, was unable to load any firmware version on any harddrive. they told me the only way to fix it was to install the old harddrive using the original data, But i lost the old hard drive... so was stuck.
So now then i tried different things like inserting PS3 jailbreak and PS3 yes while the ps3 was trying to load a firmware. hoping something different would happen.
next thing was bricking the ps3... turns it self off now? no video, no recovery menu.
nope it sounds like the firmware bug thats been in every update since 3.50 i think, it only affects it if you try and change the hard drive (won't accept the new drive) and had installed the firmware updates within the first few days of release. Only fix I know of is to send it to Sony and have them send you a refurb.
If it happened both of you after trying to upgrade the hard drive I'd be 99% sure it's the same issue for both systems.
reza684 its not the fan because even with no fan or heatsink attached it'll boot then give a warning about temps and shut itself down, if it had previously overheated and melted the solder it'd be a YLOD and would be shutting itself down after 5-10 seconds to a yellow then red blinking light.
Did you swap your hard drive? why did you format the hard drive in the PC?