I'm working on downgrading a CECHE-01 that had 4.11 on it when I got it. I've been able to use my solderless Progskeet to obtain valid dumps. I've even gone as far as upgrading to 4.21 to validate that I can get back to 4.11.
I've used the old NAND downgrading guide with the 1patchcos.bin files as well as the ultimate guide that includes the NAND-patch files. With each method, I'm able to create my flash files and write them to the PS3. Entering factory service mode fails every time.
The PS3 reacts as expected when I turn it on. There's no video, and it soon turns off. I remove the power, do the power and eject trick, and it stays on for around 10 seconds before shutting off. When I put in my jailbreak device (PSP, iPod Mini, or Arduino) as indicated by the guides, it still shuts off around 10 seconds. After putting in my USB stick and turning on the PS3, it soon shuts itself off after 10 seconds again. My assumption is that I'm not entering FSM.
The PSP shows the proper challenge and response. The serial monitor on the Arduino goes from saying "Ready" to rapidly repeating "Re" until the PS3 shuts off. The iPod... well, it's not designed to tell me anything
Can anyone provide some guidance as to how I can resolve this issue and get into FSM? I've validated my flashes using the online guides and by doing extensive hex comparisons among original files, patched files, and the patches.
Thank you for your time and for all of the wonderful information already posted in other threads,