820-02098 MagSafe cycling on/off

History: Board originally had a blown CD3217 chip. Replaced all 4 and all but U5500 is working as expected. When the MagSafe is connected, the light keeps cycling between green orange and off. PPDCIN_AON cycles between 5v and 0v, while PPBUS_AON cycles between 12.4v and 6.5v

Before i replace U5500 again, any suggestions and secondly, if i need to replace U5500, do i have to replace or 4 or can just U5500 be replaced alone?

First of all, welcome to the forum!

You can replace only U5500, but must get it from donor board, same model and position.
Just in case, reflash U5560 first; if you can get good working dump.

Thank you and that worked.

For future repairs, what flash tool would you recommend for reflashing of U5560. I was lucky this time around, i had a donor board that i could swap with. I currently have a TL866A minipro.

Any programmer works, even the cheapest CH341.
You just need to get a proper adapter board to solder such chip.