Overview
In this blog I’ll be demonstrating how to repair a HP Envy D410a Scanner which has started producing black scans. I attempted to clean the existing scanner module to no avail so instead I opted to replace the unit. I couldn’t find a service manual for the printer and no tutorials were available online so I decided to create one for the benefit of anyone attempting a similar repair.
I found it very difficult to source the replacement part for this. I found it on just one website with a price tag greater than a replacement printer: http://www.partshere.com/online/detail.asp?partno=CN517A-Scanner. I was eventually lucky enough to find an eBay seller in the States willing to extract this part from his broken printer and ship it to me.
Please be aware that while these steps worked for me, your results may vary. I take no responsibility for any injury or damage resulting from following this guide. Always be as gentle as possible when disassembling electronics and take all necessary safety precautions.
Symptoms
The printer in question was fully functional and the HP Print and Scan Diagnostics did not produce any results to indicate any issues. It seems that the image quality produced by the scanner is not covered by the diagnostic tests, just whether the scanner powers on.
The exact symptoms the HP Envy D410a Scanner presented were:
- The scans produced were mostly black with slight vertical, multicolour lines
- The scanner bulb warms up and glows as normal
- The scanner unit moves from right to left across the scanner bed as normal
- The ribbon cable to the scanner has perfect continuity across all pins
- There are no blown capacitors on the main logic board
The Repair
Tools needed are the following:
- A thin, rigid pry tool
- A Torx T10 driver
- A Torx T5 driver
1. Remove the white cover
The first step is to remove the white plastic cover around the back of the scanner bed.
Credit: Ted Haug
Using the pry tool, remove the white cover by prying the tapered edges away from the scanner bed. There are six plastic snaps and the two near the tapered edges can be released by placing the pry tool on the hinge side and pushing the snap away from the hinge while pushing the white cover outward. When the sides are free, the pry tool can be used to detach the snaps on the back as well. The prying points are indicated with arrows on the image above.
To make the process easier, I’ve also indicated the plastic snaps on the image above to show their orientation and exact position.
2. Remove the ribbon cable covers
Next, the two plastic trenches hiding the ribbon cables to the scanner motor and module need to be uncovered.
The covers are both held on with plastic snaps which come out with some persuading.
I started near the scanner hinges and worked my way backwards.
Once finished removing the covers, the ribbon cables should be freed from under the notches which hold them in the trenches.
3. Disconnect the scanner hinges
The scanner hinges are attached with a notch at the back and a springy plastic tensioner button.
To release them, push the tensioner button and while it’s depressed, push the entire scanner bed downwards toward the base of the printer. Eventually, with enough persuasion, the buttons will disappear into the scanner bed releasing the plastic notches.
To make things easier, I’ve included a picture of the hinge above, pointing out the tension button on the left and the plastic notch on the right.
4. Remove screws from under the scanner bed
Next, lift the scanner bed from the printer and flip it up side down. With the ribbon cables free from their trenches, the scanner bed should be able to rotate in one direction and sit on top of the printer. There are 13 Torx T10 screws which need to be removed.
5. Remove the scanner lid
The scanner lid holds the entire scanner bed together with some tension clips located just behind where the hinges were attached. Look for two rectangular holes at the very edge of the scanner bed.
To remove the scanner lid hinges from the tension clips, simply close the scanner lid on your finger and insert a screwdriver into the rectangular hole on the edge along the outside of the scanner bed and gently push until the lid is released. Repeat for both hinges and take apart the scanner bed.
6. Remove the connectors and disassemble the scanner bed (optional)
The scanner module should now be visible. To separate the scanner bed from the printer it’s now possible to remove the ribbon cables completely. The scanner module is moved by the servo motor using a rubber guide.
It’s not necessary to remove anything apart from the scanner module though it makes the process a bit easier in my opinion.
7. Detach the plastic scanner module surround
The scanner module is clipped on to the rubber guide at one side and the ribbon cable is attached to it using some glue and a metal clip.
After removing the ribbon cable from its trench, remove the metal clip and gently pry it away from the scanner module surround.
After freeing the surround from the rubber guide and ribbon cable, find the small Torx screw on the other edge. I believe the screw is a Torx T5 but I must admit I did not look too closely when I removed it.
Once the screw is removed, the entire assembly comes apart into a number of components including the scanner module, the plastic surround, four springs and the aforementioned screw. The springs on both ends are different from each other so please note where they came from.
8. The part to replace…
Finally, we have the part which needs to be replaced. This small module contains both the lamp and the image sensor.
When this part is replaced, follow the guide in reverse order to put the printer back together.