I soldered the teensy and placed it permanently inside the PS3 slim like explained. Now, if you look at the screenshot you will notice that I was able to dump/patch/write/verify the nor without issues thanks to the developers of the tools used.
I have an old psgrade_teensy_at90usb1286_16.hex so I programmed my 2nd teensy with that hex file and tried to boot the console in to service mode... but it seems that does not work, the screen is blank as if the video source is not available or perhaps the PS3 is not booting at all. The BD drive and HDD is already attached, the only missing piece is the upper plastic cover... Any clues?
Attached are 3 screens... One showing the whole process of dumping/patching/writing/verifying the flash using python and cmd tools. 2nd showing the integrity of the dumped flash using PS3 Flash Tool. 3rd is a comparison between two patched images, one using the cmd tools and the other using PS3 flash tool. They differ so I tried both, yet booting the console leads to blank screen as if no video source or hanged system.