Nbsss Posted December 18, 2012 Share Posted December 18, 2012 Hi, so i'm trying to resurrect my bricked asus g74sx laptop using ISP with a bus pirate.I desperately need help with the connections though, as flashrom does not detect the bios chip.I've connected the following signals:(Buspirate) MISO to DO (Bios chip)Buspirate) CS to CS (Bios chip)Buspirate) MOSI to DI (Bios chip)Buspirate) CLK to CLK (Bios chip)Buspirate) GND to GND (Bios chip)What other connections do i need? 3.3v pin from bus pirate? what do i connect this to?Let me know if you need more info.Much appreciated, Nabs Quote Link to comment Share on other sites More sharing options...
svl7 Posted December 18, 2012 Share Posted December 18, 2012 You'll most likely need to connect the write protection pin and hold pin to V+, as well as the VCC pin of the eeprom. You will need to look at the datasheet of your bios chip in order to make it work with the buspirate, there should be a list of commands which the chip supports, also the different modes. It will also tell you the exact write and read procedure. Quote Link to comment Share on other sites More sharing options...
Nbsss Posted December 18, 2012 Author Share Posted December 18, 2012 You'll most likely need to connect the write protection pin and hold pin to V+, as well as the VCC pin of the eeprom. You will need to look at the datasheet of your bios chip in order to make it work with the buspirate, there should be a list of commands which the chip supports, also the different modes. It will also tell you the exact write and read procedure. I'm a bit confused as to what "V+" is, is it the 3V3 pin on the bus pirate? Let me check if ive understood. (see attachment also) 1) Connect /WP (on eeprom) to /Hold (on eeprom) 2) Connect that wire (joining WP + Hold) to the 3V3 (on bus pirate) 3) Connect that same wire to VCC (on eeprom) Let me know if i've understood wrongly, also I'm powering the motherboard/bios chip with the PSU of the laptop. Here's the link to what the pins look like on my bus pirate: Bus Pirate I/O Pin Descriptions - DP Here's the link to the datasheet: Winbond - Serial Flash Thanks so much for your help Quote Link to comment Share on other sites More sharing options...
svl7 Posted December 18, 2012 Share Posted December 18, 2012 You don't need to power the chip with your motherboard PSU, the bus pirate will suffice. I doubt you would even get it working when the motherboard is plugged in.Just follow the description in the datasheet, it's all explained in there. Quote Link to comment Share on other sites More sharing options...
Nbsss Posted December 19, 2012 Author Share Posted December 19, 2012 You don't need to power the chip with your motherboard PSU, the bus pirate will suffice. I doubt you would even get it working when the motherboard is plugged in.Just follow the description in the datasheet, it's all explained in there. Hi mate, just letting you know i'm typing this from my fixed laptop You were right, i disconnected the AC power + battery, and connected Vcc to 3V3, and....it worked! Thanks so much Quote Link to comment Share on other sites More sharing options...
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