Hi all, my notebook Aspire 5520 was repaired at this moment successful again. This is my 3rd atempt to repair my laptop.
Sorry i have nothing photo cause my digi compact is not working now, but i think not neadly photo for this solution.
Now come to repairing the pcb.
a) Turn Aspire On with the button but Aspire shutdown after 3 seconds or later what is dependent on pcb temperature untill the contact betwen BGA chip and PCB is disconnected owing to cold link.
b) Turn Aspire On with the button but Aspire not turn on and fan on the out way is stoped. POWER and HDD Led blink in 2 seconds interval and next nothing happend
This two symptoms had I.
You should do this easy steps if you have hotair station.
I use HotAir Station and I use maximal temperature 390°C.
First you should cut all like batery, plastic removable components, and push the tinfoil under the pcb and near the NVIDIA BGA Chip from the bottom. In result you will see only the alone chip bga.
Now if you all this have, you can start with 100°C and blow the chip and his environment around 3 minutes.
Be sure that PCB can not move and is absolutelly static.
After pre-blow you have blow with airbrush direct to BGA CHIP above 1-2cm and increment the temperature SLOW and SLOW to needly temperature. I recomendet for Aspire 5520 and relevant PCB's 390°C. Later i tell you why.
Also the progress from 100°C to 390°C have to been minimal 4 minutes. Be Patient and observe this time.
With 390°C you can blow to BGA CHIP around 1-2 minutes and next
subseqently you have slow decrement the temperature to the 130°C. After take off the airbrush and wait than the PCB is cold. Until this time you MUST NOT move with the PCB or you can damage the bga connection. Is very sensitive to anythink move.
And after this attempt try turn on PCB outside the laptop cover, connect the buttons panel and Woala, laptop boot on and is working.
I in my first attempt I was trying maximal 250°C and laptop was repaired too, but after one week the laptop had again the same failed issue. My second attempt was with maximal 300°C and the same result after 10 days. This is the reason why i recomende 390°C.
I hope that this my experience help you repair your Laptop if will not another way to revive him.