Replaced SMC On 820-4924 Now Fan Spins Fast

[NHitchcock1]

Received an A1502 820-4924 for no power. There was some liquid damage around the SMC. Replaced all the components including pne of the transistors. Afterwards the device was turning all the way on but the fan would not spin. I ordered and tried a new fan. Still same result. Was able to diagnose that SMC_FAN_0_CTL was 0 volts. All the other lines on the fan connector were fine. I tried reflowing the SMC which did not change anything, still booting with no fan spin. So I ordered another SMC from Group Vertical on Ebay. After installing the SMC the fan now spins very fast, the laptop boots very slowly, and the screen resolution is small on the laptop (none of these were issues even after I reflowed the old SMC). Any help would be appreciated.

 

[2informaticos]

First of all, welcome to the forum!

I bet for incompatible SMC.
They probably sent you 3476 model.
Buy 4924 scrap board on Aliexpress and get original SMC...

 

[NHitchcock1]

Personally I think you're right, especially considering I didn't have these issues with the original SMC, even after trying to reflow. But let me ask a stupid question. This is the listing - https://www.ebay.com/itm/292388850926 and here is a picture of my original chip. The numbers appear to be the same on the chips. Do you think there's still a strong possibility of it being for the 3476 and being wrong? Like, can the numbers be the same but the programming of the chips be different? Again, almost positive you're completely right. Just asking to clarify

 

[SoloHarty]

Yes the programming is different for each board but the SMC chip is the same. Also you cannot buy brand new SMC’s, they have to come from donor boards as they cannot be programmed once out of the factory.

On the 4924 boards the fan doesn’t spin until it gets past a certain temperature.

Did you let it run for a while? Maybe reball and put your original SMC back on and test it out.