"Ink System Failure" error, cleaning contacts didn't help

Hi,

I’ll appreciate any help with my HP 8600. The printer gets the “Ink System Failure” error after turning it on. I Looked at some YouTube videos: taking an ink cartridge out won’t change the error message and allow me to hard reset the printer.
The printhead does seems to partly work because it send info on what cartridges are connected since if I try to shut the printer off with a cartridge out, I’ll get a warning message with the right cartridge.

The sensor electronics look great, however the contacts on the board behind the T6 screws (that contact with the springs) aren’t in a good shape. I tried cleaning them with alcohol and an eraser and they’re not dirty, it seems like the springs scratched part of the gold out. Is there any way to fix it? Can I rebuild the gold squares? How can I do that?

Thanks!