This is part 2 of the Samsung Chromebook Pro Upgrade.
If you read the first post, you have probably upgraded the EMMC storage. Now you can level up and go even harder and replace RAM. If you havent, then you really should read it first.
Samsung Chromebook Pro Storage EMMC upgrade - ep1
Upgrading the RAM LPDDR3
Programming new SPD data
You do the same thing before. Once you have the PCB out. The RAM is covered by a metal shield. It is not soldered on, you just need to pry it open from the corner. Be careful and be gentle. You dont want to have any flying resistor or capacitor that you will never find. Once it is opened, you can see the 4 memory chips inside.
To replace the RAM, there are 2 parts to this. First you need to modify the SPD saved in the SPI flash so that the system know the spec of the new ram. The data is saved in the 8 pin chip 25q127cs1g. It is located on the right bottom corner below the RAM. It is easy to find. You are going to need a CH341 programmer as seen in one of the picture. You can clamp onto the chip so that you dont need to remove it from the pcb to read. Macbook has surface mount chip that you need to desolder to read. So consider yourself lucky. After you read the data from the chip. Save a backup. And then read again to save another backup. The reason is to be double safe. Also when you modify the data, it is very easy to make a mistake and save the new data onto the original backup. Anyway, it is a good idea to save 2 original backup. Just do it. Dont ask! You can buy the CH341 programmer fairly cheap. Just make sure you get the clamper to clamp on the chip. If you look at the data, search for 91 20 F1 03 05 in hex. 20 is the version number, so it may or may not be different for you, if you cannot find that, try searching for F1 03 05 and see if you can find it. On the right hand side, you will see the words as seen in the picture. There are 3 different SPD value saved in the EEPROM. It is for 3 different LPDDR3 chips. K4E8E324EB-EGCF, K4E6E304EB-EGCF, K4EBE304EB-EGCG. It is 8Gb, 16Gb and 32Gb respectively. It is in Gb, so for 4 chips, it will be for 4GB, 8GB and 16GB respectively. Anyway, since all Chromebook pro comes with only 4GB of RAM, I suspect this data is for different chromebooks. In theory, we only need to change the first SPD data as that is the chip we are having. However, for simplicity, I modified all 3 SPD to the same, as the last chip K4EBE304EB-EGCG. The data should be
91 20 F1 03 05 1A 05 0A 03 11 01 08 08 00 50 15
78 78 90 50 90 11 50 E0 90 06 3C 3C 01 90
and this is the only part we need to copy and paste. The rest are for information only and is not needed. So if you copy the last set of SPD to the first and second you found, you are done. Save it and write it to the SPI chip.
Replacing the chips
Now it is the time to come to the hardest part yet. If you look at the chip, you will see it is closely surrounded by small components. Plan and practice where are you going to lift the chips when you remove it. Use the same techni to lift the chip to avoid hitting other componetnts out of place. The solder balls on this chips is bigger than that of the EMMC, but that also mean cleaning up the pads on the PCB properly is more important. Put in flux and place the new chips on and aligh it with the corner marking on the board. Pay attention to the pin 1 dot on the chip to avoid putting it the wrong way. Again, when you see the flux bubbling and smoking like crazy, it means it is almost done. But keep heating it up for a bit more to make sure.In theory, the chip should slide in place when the solder melt if it is not too out of alignment. Let it cool down more before touching the chips to make sure it is soldered on and does not move. Good job. But you are not done. Check the surrounding components carefully to see if any is out of alignment. Keep in mind those capacitor are sand size. So do use a good magnificating eye piece. If any is out of place, you need to put it back. If everything looks ok. Time to plug it back in and test.
You should check the EMMC before doing the RAM. That way, you know it is the RAM, not EMMC. Otherwise you will have no clue and do everything over again. Slow is fast. Keep in mind.
Have fun.