Repair NVIDIA GTX 1070 *need help identifying smd*

[baymax9966]

Hi All,

I've been trying to get my video card repaired and stuck on this part/IC that I can't get my hands on, if any of you know please write a reply

PS : the picture is not mine since my phone can't get it focus, mine was "7J3G" if that makes any different

thanks!!

[gamalot]

Richtek RT8816B Dual-Phase PWM Controller with PWM-VID Reference

https://datasheetspdf.com/pdf-file/1425667/Richtek/RT8816B/1

[wraper]

It's a memory VRM controller. The last symbol varies. I never figured out what it is but it's pin compatible with uP1666Q (did not try to use it as replacement).
These cards usually fail with RAM VRM high side Mosfet going short and most of the Ram chips going short after that. GPU usually seems to survive. VRM controller may or may not fail.

[baymax9966]

Richtek RT8816B Dual-Phase PWM Controller with PWM-VID Reference

https://datasheetspdf.com/pdf-file/1425667/Richtek/RT8816B/1

does the A and B version is the same thing? I can only find the RT8816A here atm

It's a memory VRM controller. The last symbol varies. I never figured out what it is but it's pin compatible with uP1666Q (did not try to use it as replacement).
These cards usually fail with RAM VRM high side Mosfet going short and most of the Ram chips going short after that. GPU usually seems to survive. VRM controller may or may not fail.

thanks but I can't find uP1666Q here and have to order from aliexpress which will take forever to be delivered, so i'll go with the richtek
I have some spare GPU that I can pull the VRAM from but i've never attempt to do BGA rework before since the only tool I have is just heatgun/blower

[wraper]

does the A and B version is the same thing? I can only find the RT8816A here atm

RT8816B datasheet says that marking is 7J= and the last two symbols are a lot code. Listings selling RT8816A I found show IC with 7J= as well. So I checked a datasheet of RT8816A https://www.richtek.com/assets/product_file/RT8816A/DS8816A-05.pdf and yep, it's 7J= as well. So likely it's RT8816A on your graphics card to begin with. Also I did not find any differences in the datasheets whatsoever including specifications and application circuits, they seem to be exactly the same. So RT8816B could be simply a newer revision.

[wraper]

I have some spare GPU that I can pull the VRAM from but i've never attempt to do BGA rework before since the only tool I have is just heatgun/blower

You should measure resistance of RAM power rail to GND. IIRC it should be somewhere around 80 ohm or at least in about this ballpark. If VRM MOSFETS are removed (to prevent shorting to GND if they are faulty) and resistance is still very low, like in single digit Ohms or below, then either some of RAM or GPU should be bad.