Here’s a neat little tool that you can use to check the base firmware on your PS3–just in case you want to know how low your firmware downgrade can go.

Below is a list of PS3 models (for fat and slim) and their base firmware (credit tito1):

Base Firmware for fat PS3 model

  • 40GB CECHG04 Fat OFW 1.90 (Max. Downgrade)
  • 40GB CECHG04 Fat OFW 1.90 (Max. Downgrade)
  • 60GB CECHC04 Fat OFW 1.0 (Max. Downgrade)
  • 60GB CECHC04 Fat OFW 1.1 (Max. Downgrade)
  • 80GB CECHK04 Fat OFW 2.16 (Max. Downgrade)
  • CHECHE11 80GB —- Fat OFW 2.40 (Max. Downgrade)
  • Fat DECR1400A —– FWD 2.60 (Max. Downgrade)
  • 80GB CECHE01 Fat OFW 1.00 (Max. Downgrade)
  • 160 GB CECHP04 —- Fat OFW 2.45 (Max. Downgrade)

Base Firmware for slim PS3 model

  • 120Gb SLIM OFW CECH2004A —— 2.70 (Max.Downgrade)
  • 120GB SLIM OFW CECH2001A 2.70 (Max.Downgrade)
  • 250GB SLIM OFW CECH2004B 2.70 (Max.Downgrade)
  • 320GB SLIM OFW CECH2504B 3.40 (Max.Downgrade)

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The tutorial below is an excerpt from the PDF file created by DeathHades (roughly translated).

Minimum Version Checker tutorial:
This tutorial will teach you to how to know the base firmware of your PS3 with a few steps and images.

The first thing you have to [have]:

  • A PS3
  • MinVerChk [file]

The steps:

  1. Transfer the MinVerChk file to a USB flash drive, as if it were an upgrade (e.g. x:/PS3/UPDATE/PS3UPDAT.PUP)
  2. Insert the USB flash drive into the PS3′s USB port.
  3. Install the update from XMB (This will fail and display the base firmware).

Download Minimum Version Checker »

The photos:

min ver check (4)
min ver check (3)
min ver check (2)
min ver check (1)

source Demonhades