"Please help me locate the temperature sensor on this MacBook"に関する回答So, the sollution is pretty simple. Remove R8556 R8558 for board 820-00840. These are SMBUS_SMC_1_S0_SDA / SCL ALS Lines. since this laptop will fail because of the broken LCD Cable, display replacement makes zero sense.
"Internal hard drive disk not recognized"に関する回答I believe this problem is caused by dead capacitors in the power circuit. It explains all syptoms. I tried two replacement cables and it did work on low mAh hard drive i used for tests in computer service nearby. When i came home and tried my own wd black, it did not even started. I think it could be fixed by capacitor replacement but thats really tricky thing to do as there is no schematics availible.