I assume you put the dongle firmware on the FSM dongle? what dongle are you using? what guide are you following? you probably aren't getting help through lack of details given. do you get a blue light come on? I think from memory there is a FSM dongle firmware that does that (E3).
It had a modded firmware to stop the loss of bluray and doesn't show the factory screen. I can't remember if it just turns off again or goes to "Connect the controller using a USB cabl, and then press the PS button" screen. I think you switch your power off from there. Find a different guide.
Are you using an E3? If so, check that you have the correct firmware for it. I believe there was an updated one that would boot the PS3 into FSM while the original would go into the regular XMB and you would have to power it off and on.
OK that's weird. So how do I downgrade from 4.21 with an e3? Can some one point me in the right direction. I've so far followed the guide as well as numerous videos on youtube and they all go thru the same steps...
1. You need the E3 Flasher NOT the Cardreader
2. you must make an Dump of your NOR-Flash (E3 or Progskeet...)
3. You need the Patchfile for your Dump to bring your System in the FSM.
4. You must Flash your Dump back to your NOR.