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

Last time we looked at how to uninstall the motherboard of your Epson Workforce WF-3640 correctly. So today, we’ll look at how to install a new motherboard. For the most part, I will be working off of this worksheet.

We’re going to start by putting the screws back in the motherboard. Then we’re going to put the cover with the wifi chip back on top and put the four big screws back in their places at each corner. Now we can put the motherboard back on the printer.

When putting the motherboard into your printer, there are three things to watch out for.

1. The black piece must be behind the optical sensor.
2. Make sure none of the wires, especially the ground wires, are blocked by the motherboard.
3. You’ll have to push the fax unit back.

Step 1

Bend the wires forward, making sure you can see the ground wire. You can move the fax unit back a bit, making certain the black piece is between the fax unit and the optical sensor.

Step 2

Now, replace the screws that attach the motherboard to their original positions. There should be a total of five screws to install. The shorter screws will be for screwing metal to metal, while the longer screws connect metal to plastic. Once those screws are in place, you'll have to work toward the back on the top of the mainboard.

Step 3

Look for a GGW wire (gray, gray, and white). There’s also a small “W” which means the head will be white. You'll need to plug it into the port at the top right corner of the motherboard. Now, locate the three FFCs from the paper feed, the WIC, and the fax unit. Remember which one is the small, which is the medium, and which is the large. The paper feed will be the smallest, so you'll want to put that down first.

The blue sides of all three FFCs should be facing the front. The thinnest FFC goes all the way to the back of the motherboard, toward the top. Then you’ll find three wider FFCs with ironcore holding them in place. Plug those in, and then we’ll install the side cover.

Step 4

To install the side cover, put the bottom tab in first. Then you can turn it gently into place until you hear it click. There will be one screw for the side cover that you need to install. After you’ve put the cover in place, we’ll do the LCD panel.

You’ll see that the LCD panel has an FFC cable. There will be a black KRK wire and a black and red wire. If one of the wire descriptions has a lower case “y,” the wire you’re looking for will have a yellow head. You’ll also need to find the ground wire.

Step 5

You will need to install two screws to secure the front LCD panel into place. Now you’re going to attach the ground wire. You’ll notice that the 3640 model will have a red socket and an FCC socket, whereas the 3620 model doesn’t. You’ll need to attach the power cable.

If you are using the worksheet I recommended, you’ll notice a diagram with numbers corresponding to where each wire goes. In the spot indicated as number four, you will insert a black wire with a red head. Number five is a clear wire with a white head. Number six is a black and red wire with a black head. Number seven is a black wire with a black head. Number eight is a black and red wire with a red head.

Step 6

Put the cover back on and secure it in place with seven screws. You’ll have to work with the scanner's hinge before installing the seventh screw, the one secured at the scanner’s hinge. The top of this hinge should fit into a place just to the left of the wires. Practice putting it in and taking it out until you get used to it. Close the scanner, and it should lock in place. If it doesn’t, you might need to bend it back slightly.

Step 7

Now we get to go back to working with the wires. You’re going to need a black, gray, and white wire with a white head and plug it into the number two spot. Number three is a black and red wire with a white head.

Next are four colorful wires with a white head, followed by a black and red wire with a yellow head. Make sure the iron core is connected to the FFC before installing it. Lastly, two ground wires share a screw.

Now you can put the fax cover back and secure it by putting two screws in the scanner and two more into the fax cover.

For a detailed video guide for this article, you can watch my video here. We hope you enjoyed this article and found it helpful!