you cant enter service mode on all firmwares plus you need a dongle and all that crap
try these steps
1. Turn off Playstation 3 duh
2. Hold The power button down; The system will turn on and turn off once again.
3. Once the System has been shutdown hold the power button down again until you hear 2 consecutive beeps
4. When you hear the 2 beeps take finger off power button.
5. You will be promted to plug in your controller via usb and then hit the PS button
6. The Recovery menu will pop up.
edit: ahh its screwed because if it was a failed update itll give u a red screen of death that sounds like a hardware issue since itll auto kick the fans when power is applied with no push of any buttons
edit 5/5/12
sure the power/eject button isnt messed up?
after reading this thread again sober lmao sounds like its doing a force eject/fan test
when you power on the ps3 while holding the eject button itll force the blu ray drive to eject anything in the drive great method for ylod with games stuck in the drive
itll also run the fan test which is basically what your describing itll kick the fan from silent medium high and full blown fan speed youll hear it in series
try replacing the power eject button remember not all slims are part interchangeable trust me there not lmao i learned the hard way once use the cech etc on the slim to find replacement parts
edit:sorry i was trying to help guess i forgot to click the modify button sue me
please do not double post you should know the rules 3D0