Remove Epson WorkForce WF-3640 / WF-3620 Motherboard (Main Formatter Board)

Today, we will look at installing and uninstalling the motherboard from your Epson Workforce WF-3640 printer. We’ll start by removing the two screws on the cover of the fax machine. Next, we’re going to work on the scanner square.

You’ll see a cluster of wires. Carefully start pulling them from the motherboard. There will also be two black ground wires secured by a screw. Go ahead and unscrew that to remove those as well. You’ll see a wide cord called the FFC cord attached to the motherboard via an iron core. This iron core is attached to the motherboard using double-sided tape, so you can go ahead and pry that off. Remove the iron core.

On the top of the scanner, you will find two screws. Remove those and press the tab holding the scanner in place to the right to take it out. Once you have removed the scanner, there will be seven screws to remove. One is going to be what’s holding a hinge in place. Remove that, as well as the hinge itself.

The second screw is going to be underneath where that hinge was. Number three will be inside a hole on the other side of the printer, and the fourth screw will be right next to it. In the center front of the top of the printer, there will be two screws. You want to remove the one towards the front. The sixth screw is on the top to the right, and the seventh is in the hole next to it.

Do not attempt to remove the cover until you remove all seven screws. After you have done so, the cover will be fairly loose, and you should be able to remove it easily. Use your hand to lift a little bit around the edges until it comes off.

Now we’re going to be working on the bottom of the main board. Unplug the wires from this as well. The thick blue wire is the one that provides power. If you need to remove the power supply, take out the screw to the left, and the power supply will slide right out. Next, remove the screen and front panel and the wires connecting it. Set that aside for now.

Remove Side Cover

Now, move to the side cover. This won’t be necessary for what we’re doing today, but it’s good to know how to do this in case you need to in the future. If you look straight down into it, you’ll see where the screw is. Remove that and lift the tab next to it with your finger. The cover should now be loose, and you can remove it by twisting it a little horizontally.

Now you’ll see three FFC cables with iron cores and a fourth 9really thin) FFC cable. Carefully untangle and remove those. Four screws secure the motherboard in place. Go ahead and remove those. Remove the front ones first. One of the screws you need to remove will be deeper and harder to reach, so be careful not to break anything. The main board should be loose now, only held by a small cable. Figure out where it’s connecting and disconnect it. Carefully pull the worse down to the slot in the middle.

Holding the two FFC cables away and the other wires in the middle, push the fax unit holding it in place back and jiggle it out. There will be four screws, one on each corner of the piece you’ve just removed. Take those out and remove the top cover. Remove the screws by the USB ports.


We hope you enjoyed this blog post! If you'd like a visual walkthrough of this process, you can find one on my YouTube channel. I also offer a worksheet to help you with this process on my website. You can watch this video for more detailed instructions on installing a motherboard. Happy printing! 

Apr 25th 2022

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