For $29/mo, we provide access to advanced level technicians who will answer your questions on any Macbook board related matter to the best of their knowledge promptly & walk you through how to solve your problem so you can deliver a working board to your customer.
Didn't see two Si dies on the CPU?
Guess which is which?
If you follow PCH lines in schematic, where they go?
Boardview should help better.
We discussed so many times about heating BGAs on the forum.
I gave you some temp/time values; you should use 20-30% of air flow.
As I said, the temp refers to chip, not to hot air station.
To achive 200 degrees on the board, the station must be set at 350-400 degress; depends the model and every unit has also its tollerance.
Distance hot air nozzle to board also must be considered.
You should practice with scrap boards.
Is all about practice, we all do it at "the eyes" (only one in my case).
The goal is to burn eventually accumulated crap underneath, not to melt the balls.
Once the (good quality) flux starts to boil, shouldn't increase the temp too much; don't exceed the time.
BTW, the role of the forum is to assist on the repair process.
For personal training, contact Rossmann staff...