Don't ask how to hack password. (BIOS Passwords)
#59554 by Th3_uN1Qu3
Sun Feb 10, 2013 2:20 am
Bought this notebook a couple days ago to fix and keep for myself, or maybe resell, we'll see.

Trouble: No power absolutely. No LEDs no nothing. Not even battery charging LED. I have confirmed the presence of 3.3v and 5v standby, there is 3.3v on the power button as well, but when pressing power nothing happens.

I don't have a schematic for this mainboard (Wistron LA56). However, i found a schematic for a LA46, which is the same in many areas, except the PWM controller for the 5v and 3.3v main rails. I've also found on a Polish forum that the flash for the KBC frequently goes bad on this model. I downloaded two dump files from there, from two different configurations of this mainboard, Lenovo B560/G560 with integrated graphics (like mine is) and V560 with discrete nVidia GPU. The content is the same and the CRCs match, and the place i got it from says the dumps are tested. So i'm fairly sure the content of the KBC flash is the same on all versions of this mainboard, and they are going to work in my V570 as well.

Judging by the amount of stuff that the "keyboard controller" is actually responsible for as the LA46 board schematic shows, no wonder it doesn't power up at all if its flash is bad. On this mainboard, not even the main BIOS receives power right now (it's on the main 3v3 which is controlled by the KBC), so no way in hell is this going to boot.

Trouble is, i don't have anything to program the SPI EEPROM with. I phoned a friend who said he can borrow me his Bus Pirate, i think that will work. I'll first dump the contents of the existing EEPROM and compare with the dumps i downloaded, to see if it is truly corrupted. Then i'll reflash (swap in another EEPROM if necessary). If that doesn't fix it, i'll be ordering a KBC as they are available on ebay for $7. No luck on the datasheet for that either, so i'm lucky i got the schematic of the LA46 board, which has the pinout of this particular KBC (Nuvoton NPCE781EA0).