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Tutorial - Hardware Needed for PS3 Downgrade | Se7enSins Gaming Community
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How to bypass update 4.86 on ps3 fat? Has firmware: Cobra 8.01, and mmCM Version 4.85.01 : r/ps3hacks
I purchased a PS3 backward compatible from ebay for a good price and I'm impressed how clean it is. However... It's still on firmware 2.50. Should I update the firmware? : r/PS3
How To] Downgrade Fat PS3 From 4.66 to 3.55 Firmware Using E3 Flasher Tutorial (Part 3 of 3) - YouTube