Swapping the CM4 Module & Restoration from backup – Upgrading Homey Pro to 8GB RAM – part 3

Introduction part 3

This is it. The point of no return. We have the new hardware delivered, and we have a safe “Golden Image” backup of your system from Part 2. Now, it’s time to perform surgery.

I’ll be honest with you: the first time I looked at the seamless casing of my new Homey, I hesitated. It feels wrong to cut into a device that costs this much. But trust me, the build quality is solid, and as long as you are patient, this is a very straightforward swap. Grab a coffee, clear your desk, and let’s get to work.

Part 3 takes about 30 minutes (including restoring backup).

Step 1: Breach the Hull (The Surgical Way)

The Homey Pro 2023 is a sleek puck with no visible screws. Most guides tell you to rip off the entire rubber ring on the bottom. Don’t do that. The glue is messy, and it never sticks quite right again.

Instead, we are going to be precise. Place the Homey upside down on a soft surface (like a mousepad) to protect the top.

1. Locate the Screws: Run your finger along the rubber ring on the bottom. You will feel four distinct soft spots or indentations. These are the hiding spots for the screws.
2. The Incision: Take a small, sharp knife (an X-Acto knife is perfect) or the tip of a pair of fine scissors. Carefully cut away only the small circle of rubber covering each screw hole.
3. Unscrew: Now that the screw heads are exposed, grab your Torx T9 screwdriver and remove them. Put them in a small bowl – they are tiny, and they love to roll onto the floor, never to be seen again.
4. Pull apart: Now comes the part that feels scary. Separate the bottom plate from the rest of the body. Work your way around the rim.

Step 2: The Heart Transplant

With the bottom cover off, the motherboard is revealed. You are looking at the brain of your smart home. In the center, you’ll see a heat sink and under that a smaller circuit board clipped onto the main motherboard. That is the Raspberry Pi Compute Module 4 (CM4). You must remove the heatsink in order to get to the CM4. Remove the four screws as shown in the picture.

Warning regarding Thermal Pads

Before you rip out the heatsink, notice that there is likely thermal pads (a soft, squishy square) connecting the chip to the heatsink. This is crucial for keeping the Homey cool. If it sticks to the old module, carefully peel it off and place it back on the heatsink, so it’s ready for the new module. There are more picture later on.

The Removal

• After you removed the heatsink and carefully storing the nuts and bolts and small spacers (in plastic), that are below the heatsink, you are ready to continue.
• The CM4 is connected via two high-density connectors on its underside. It doesn’t slide out like RAM in a laptop; it pops straight up.
• Gently grip the edges of the old CM4 module. Pull it straight up with even pressure. It will release with a firm “click.” Set the old module aside safely – this is your ultimate backup if everything goes wrong.

The Installation

• Take your new 8GB/32GB CM4 Module. Align it perfectly over the connectors on the motherboard. This is a “feel” thing. You want it to sit flat before you push. Make sure that you orientate it the same ways as the one you just removed.
• Once aligned, press down firmly on the edges of the module (directly over the connectors) until you hear and feel a satisfying snap. It should sit completely flush and parallel to the main board.
• Slide the plastic spacers back onto the bolts. If the thermal pads stuck to the old CM4, transfer them to the new one (or place them back on the heatsink). Finally, place the heatsink on top and secure it with the nuts. Do NOT tighten too much.

Step 3: Reassembly & The “Dead” Device

Put the bottom cover back on. Because we used the “surgical” method, you don’t have to mess around with glue. Just insert the Torx screws through the holes you made in the rubber and tighten them. Remember, you are screwing into plastic, so stop when you feel resistance – don’t overtighten.

Now, here is the moment that stops people’s hearts: If you plug in your Homey now, absolutely nothing will happen. No lights, no spinning rainbow. Nothing.

Why? Because the new brain is completely empty. It doesn’t even know it’s a Homey yet.

Step 4: Breathing Life into the Machine

We need to restore the soul we saved in Part 2.

1. DFU Mode: Perform the acrobatic move again: Paperclip in the pinhole -> Hold button -> Plug in USB (connected to your computer) -> Wait for the Orange light.
2. Browser Tool: Go back to usb.homey.app on your computer and connect.
3. Restore: This time, select Restore Backup. Point it to the file you saved in Part 2.

The upload might take a while depending on your USB connection. Once it reaches 100%, the Homey will reboot. When you see that LED ring light up with the familiar animation, you can high-five yourself. You are now running on 8GB of RAM but storage remains the same…

Don’t worry, you haven’t been scammed. We just have one final software hurdle to clear in Part 4.

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Comments and questions??

You are always welcome to leave a comment or share similar experiences in the comment section below (go there).
Have a great day. 🍀

Gallery

The Roadmap

We are still going to take this step-by-step to ensure you don’t end up with a bricked device. I’ll have this paragraph in each post in order to easily go back and forth:

• Part 1: The Strategy & Shopping List

• Part 2: Backing up the Homey OS

• Part 3: Swapping the CM4 Module & Restoration from backup

• Part 4: Unlocking Potential – Jailbreak & Storage Expansion

Want to help?