Went through the process of upgrading from rebug to cobra on my PS3 fat (Model: CECHK01) and after completing the process and installing multiman, the system now won't boot. When I turn the power switch on, the power button shows a red light as normal. When I press the power button, the system beeps, led turns green for a split second, I hear a click and the led off and nothing happens. The system goes dead. Here's a full breakdown of what happened:

• Previously had rebug installed, but accidentally filled up the internal storage

• Did a full system restore and quick formatted the internal drive

• I wanted to redo the mod process from scratch, so I followed this tutorial: https://www.youtube.com/watch?v=suM4dUAYUPE

• No issues were encountered throughout the process and I flashed EvilNAT CEX (4.90 from here: https://www.psx-place.com/threads/cfw-4-90-evilnat-cobra-8-4-cex-dex-pex-d-pex.39743/)

• The system shuts off after the firmware update (doesn't reboot). When I try to turn it on, I get the failure for the first time. Turn power switch off, turn switch on, press button, brief green light, then nothing. I leave the power switch off for a few seconds and try again, then the system boots. I think nothing of it

• I continue the process following the video above and attempt to open multiman for the fist time. The screen goes black, my display goes into sleep mode stating there's no video signal. The PS3 power button doesn't appear to do anything. Controller doesn't either. After some time, I flip the power switch on the PS3 to power it off.

• Flip the power switch back on and now I cannot get the system to boot. When I turn the power on, the LED is red, when I press the power button, the system beeps, the LED turns green briefly, I can hear a click which I assume is the HDD or PSU switching on briefly, then the LED goes black and there's nothing. I never hear the fans spin up or anything like that. It almost instantaneously goes from green LED to click and then nothing.

I tried removing the internal HDD and the system still does this. Any thoughts what the issue can be? Did the firmware brick itself or did I have a hardware failure in the middle of updating the firmware?

My initial guess would be a FW brick, but I'm puzzled why the system booted initially and then gave me this problem AFTER successfully launching the FW and then attempting to launch multi-man.

Thanks!