Samsung Chromebook Pro is one of my favorite device. It just has the best form factor and resolution. Its weight and thickness is easily one of the lightest function laptop out there.
It originally comes with 32GB of EMMC storage and 4GB RAM.
I am upgrading my Samsung Chromebook Pro to 128GB EMMC and 16GB RAM.
I wanted to upgrade to 256GB EMMC, but the cost is just too high. Upgrading to 128GB is just around $10 USD while 256GB is almost $100.
I will update this post as I progress with the process.
First part is of course removing the write protect screw and installing the UEFI firmware. Removing the screw sounds easy enough but as a matter of fact it is kind of tricky. I’ve opened my chromebook and removing the main board so many times by now that I do not even need to think about it. But I will briefly talk about the most important part and the tricky part.
Samsung Chromebook Pro Caroline with Skylake removing
screw
I was trying to modify my Chromebook Pro to alternate os. The first step is to remove the fw lock screw. I checked the picture from mrchromebox site and thought it is simple. It is not! I had to open up and remove the main board 2 times to figure it out. So I think it may be helpful to someone in the future down this road if I document this since I can’t find anyone did.
I will start from after the cover was opened since that is straightforward. After you exposed the inside of the Chromebook, the goal is to completely remove and take out the main board. I start by removing all connectors. If not including the wireless connectors, there are 8 connectors to remove as marked on the picture. 8, and 5 is connector that you lift it up from the board. So it is not pulling but lifting. There is no locking mechanism. 8 is the battery so I would remove it first. 1,2, 6,7 is the normal connector that you lift up the black part and pull out the flex cable. Be careful not to break the black latch as it is much much harder to fix than you may think. I once render the whole board useless by breaking a simple latch. 3 is pulling away from connector. There is no lock. 4 is more tricky. There is a metal bar locking the cable. You need to lift up the metal locking bar then pull it away from the connector similar to 3. Don’t forget the wifi connector. Then you remove 3 silver and 2 black screw to lift the main board. Once you take the board out, flip it over and you will see 4 screws that lock the heat sink. Be careful about the latches of the connectors on the other side of the board. If the latch is up and you apply pressure, you can easily break it. Once the heat sink is removed, go back to the other side and look at the screw hole as marked in picture 2. People keep saying remove the screw, but in reality the real devil is a conductive sticky ring that stick on the circled screw. You need to remove that sticker. That sticker connect different pads on the screw hole together that lock the firmware. I removed that sticker ring and sticker an electrical tape on top of the screw hole. When I reinstall the heat sink, I omitted this screw. Putting it back together is simple. Just reverse what you did. Make sure you count the connectors you reconnect. And connect the battery last. It is easy to miss some connectors, so it is a good idea to count.
The second part is software part and there are plenty of helpful information in this site.
After you flashed the UEFI to the SPI Flash and checked it is working, it is time to move on the the fun part.
Replacing the internal storage EMMC
Warning: Flashing the firmware to UEFI is a risk to damage your machine, replacing the EMMC and RAM are another level. The risk of permanently damaging your machine is 100 times higher. There are just so many things can go wrong. If you never ever done BGA rework in your life, dont even try. It is almost certain you will damage the board. You’ve been warned.
EMMC is easier to replace than RAM in some sense as EMMC you just need to replace the chip, while for RAM you need to also modify the SPI flash to reflect the new memory. However, the pins in the EMMC are a lot smaller than that of the LPDDR3 chips. The EMMC uses FBGA153. It has 153 pins. However, only a few is used. Most of the pins are nc. So if you break a pin on the board when you are cleaning the pads. Dont panic just yet. Take a good look at the broken pad and see if there is any trace connecting to it. There is a good chance it is a nc pin. Also, you can check EMMC FBGA153 pinout to see what that pin is for. In my experience, the nc pins are a lot easier to break than those that are connected, but dont go crazy when cleaning the pins. The smaller the pins, the easier to break. Go light when cleaning the pads. I cannot stress that enough.
My original EMMC is SanDisk SDINADF4-32G as seen on the picture. I ordered a SanDisk SDINBDA4-128G. You can use Samsung if you want, but make sure you order the same package in FBGA153. I originally wanted to upgrade to 256GB, but when I see the price, I gave up on the idea as it is like 10 times the price of 128GB. I got my Chromebook Pro for like $25. So I am not ready to spend $100 for the EMMC. For me, upgrading from 32GB to 128GB is a huge improvement already. So I am satisfied.
There are 2 way to go about this, you can use work station hot air gun to remove this or use a heating plate. If you look at the bottom side, it is mostly empty, if you have a small heating plate, it should work. However, it is more risky since more component will come loose and have a chance to fall out of place. I go for the safer option to use the hot air rework station. Lead free solder melt at around 425F. I set my temperature to around 750F to 800F. You do not want to use too high a fan speed. Keep it low. The last thing you want is blowing the parts out of place and scramble to figure out where it is/was. Use lots of flux and dont inhale it. When you look at the EMMC chip, there are some capacitor and resistor around it, so be very careful when lifting it. That being said, the clearance for the EMMC is higher than that of the LPDDR3. Some people will lift the chip from the side, but I opened up my tweezer to wider than that of the EMMC and clamp it from both side to lift it. If you have to drag it since it is hard to clamp right in the middle, drag the lower side towards the middle of the BGA153 and lift it so that you are not going to slam the surrounding components out of place. Before you even start heating up the chip, have a plan on where are you going to hold the chip and lift it. Almost have a plan before heating anything up. Before you heating up, make sure you cover up the plastic connector around where you heat. The other components will likely be finem but those plastic connector will melt. If it melt, you can end your project early and donate it to recycle. I cover it with metal heat shield. After you started heating, when you see the flux smoking or bubbling like crazy, you can get ready to start trying to lift the chip. Do not force it to come out. You tap it lightly and see if it moves, if not, heat up more and try again. Keep repeating the process until it moves when you tap it from the side. Please just push it a little. Otherwise you will slamp the chip into surrounding components. When you lift the chip, be steady and keep calm. If you move the surrounding components, it is ok as long as you know where that component was and where it went. Most components are sand size so good luck finding it if you drop it somewhere far from where it was.
Once it is removed, use wick to clean the pads. Do not drag it hard with soldering iron. Do it lightly. Or even better, use the hot air to melt the solder and clean it with the wick. When I clean it lightly with the wick and soldering iron, I broken 3 pins. I cleaned it lightly but still 3 pads are gone. Luckily, those pins are NC so it still works. So if you break some pins in the process, dont panic just yet. There is still hope. If I do it again, I will use hot air and wick just to be safe.
Most of the EMMC you buy will come with pads pre balled. But do check the balls and make sure they are good. Ideally, you would want to replace the balls with low temperature solder, but I am just too lazy to do it. If you do not have the FBGA153 stencils, and you are not skills, it may do more harm than good to reball it.
The trick to make this work is to clean the pads on the board and leave the solder ball on the chip. Only one of these 2 components should have solder on it. This way, the chance of uneven soldering from any of the pins is lower. There are 2 marks on the PCB on 2 corners of where you should place the chip. It helps you to place it properly. Be use a high magnificating eye piece to check it when placing it. You want to place it as perfect to those 2 corners as possible. The rest is just luck. If it works, it works, if not, you repeat the process until it do. I was luck and it works on the first try.
From my understanding, there is no easy way to check if it works. You have to put the board back into the laptop and power it up. Since the storage is gone, you will need to boot with USB stick and reinstall Fedora to check if it is working properly. If it works, congratulations. You can now move on to another level; replacing the RAM. More fun coming.