ProBook 6470b

Test Clip that I used

The HP ProBook 6470b models that I have encountered have used a MX25L6406E 64M-BIT CMOS SERIAL FLASH BIOS chip. It is a SOIC8 package and the lower plastic chassis of the laptop must be removed to access it easily using the SOIC8 test clip

Lets just assume that if you use any of these instructions on any of your own (or someone elses) equipment that you do so at your own demise. Kittens will die and babies will go hungry if you screw anything up. DO SO AT YOUR OWN RISK!!

I have found that you do not need to connect the Vcc lines on any of the pins indicated if you let the laptop power brick provide the proper regulated voltage. If you use a genuine HP power supply and do not have the battery connected, it may detect the absence of the battery and turn off. Also, if you use an aftermarket supply with poor regulation, you may experience poor consistency in your reads and SHOULD NOT flash your BIOS over SPI if this is the case. If you cannot get consistent reads.... DO NOT WRITE!! You have been warned My suggestion is to make sure you can get, at a minimum, THREE full binary reads that have the same checksum. If you cannot do this, you may have to resort to supplying the proper Vcc to the chip externally with proper regulation. DO SO AT YOUR OWN RISK.

Below are the connections that I made. Factory HP Power Supply Brick and the laptop battery installed for Vcc.

Bus Pirate <----> MX25L6406E
  CS<-------------->CS#
MISO<-------------->SO/SIO1
 nc <-------------->WP#
 GND<-------------->Vss(GND)
MOSI<-------------->SI/SIO1
 CLK<-------------->SCLK
 nc <-------------->HOLD#
 nc <-------------->Vcc

BIN Dumping Ground

• CNU3419FKT.bin
• CNU3419FKT.NoPassword.bin