Playstation 3 BRICK SUR-001

Some guy from my area tried to downgrade his ps3 and bricked it . He gave me his dump which is valid. He also soldered tristate to gnd as I told him so that he can just flash fun it. The problem is that the Ps3 runs for like 3 seconds then turns off with a blinking red light even though it it tristate to gnd. Is there anything I can do like resolder the points again to fix the issue. He also told me that he used a wire from a usb cable (Black) to tristate to gnd. Is the problem the cable so I can go ahead and use a copper wire to do that or is something else like the Southbridge dead???