Tools Featured in this Teardown

Introduction

As a continuation of the Epson Stylus Photo 820 teardown, this is a teardown of the printer's printhead.

This teardown is not a repair guide. To repair your Epson Stylus Photo 820, use our service manual.

Image 1/1:
  • Here it is - the Epson Stylus Photo 820's printhead assembly.

Add Comment

Image 1/3: The dual ribbon cable connector can be seen hiding in the back of the printhead. Image 2/3: The dual ribbon cable connector can be seen hiding in the back of the printhead. Image 3/3: The dual ribbon cable connector can be seen hiding in the back of the printhead.
  • The ink cartridges can easily be removed after opening up the cover. +10 for repairability as this is the only part that will need to be replaced.

  • The dual ribbon cable connector can be seen hiding in the back of the printhead.

Add Comment

Image 1/2: On the other side of the board is a resin blob hiding a chip. Image 2/2: On the other side of the board is a resin blob hiding a chip.
  • Each ink cartridge has a tiny circuit board with 5 contacts which can easily be removed with a metal spudger or similar tool.

  • On the other side of the board is a resin blob hiding a chip.

Add Comment

Image 1/2: And... The circuit board comes out! Image 2/2: And... The circuit board comes out!
  • Only one screw holds the printhead assembly together.

  • And... The circuit board comes out!

Add Comment

Image 1/1: 3 very dense ribbon cables ripped off whatever they were attached too when the logic board was removed.
  • Houston, we have a problem.

  • 3 very dense ribbon cables ripped off whatever they were attached too when the logic board was removed.

  • Hopefully, no one will have to repair one of these.

Add Comment

Image 1/1:
  • All that is left in the plastic block is the 10 spring contacts that connect the ink cartridge chips to the main board.

Add Comment

Image 1/2: This flexible circuit connects the actual print head to the circuit board. Image 2/2: The dual ribbon cable connector
  • Let's take a look at the circuit board.

  • This flexible circuit connects the actual print head to the circuit board.

  • The dual ribbon cable connector

  • The contacts for the ink cartridge chips

  • This appears to be a test point of some kind.

  • This decoder/multiplexer chip on the flexible circuit appears to take 16 inputs and provides over 240 outputs for the print head.

Add Comment

Image 1/3: The print head is held in place by a metal cover that is held in place with blobs of melted plastic. Image 2/3: This colorful assembly is the ''actual'' print head. Image 3/3: This colorful assembly is the ''actual'' print head.
  • Finally. Time to get inside the print head.

  • The print head is held in place by a metal cover that is held in place with blobs of melted plastic.

  • This colorful assembly is the actual print head.

Add Comment

Image 1/2: Here you can see the contacts for the cartridge chips. Image 2/2: Here you can see the contacts for the cartridge chips.
  • This row of 6 holes is the end of the tubes that transfer ink from the cartridges to the print head.

  • Here you can see the contacts for the cartridge chips.

Add Comment

Image 1/2: Penny for scale Image 2/2: 10 Euro Cent coin for scale
  • This is a close-up view of the most important part in any inkjet printer.

  • Penny for scale

  • 10 Euro Cent coin for scale

  • For scale in the third dimension, the printhead is 0.3 mm (0.01 inches) thick.

Add Comment

Image 1/1: Time for Science with jBot-42!
  • So, you may ask, how does this wafer-thin piece of metal that I call the printhead actually print?

  • Time for Science with jBot-42!

Add Comment

Image 1/2: Ink flows from the cartridge into the printhead through the red circles. Image 2/2: Ink flows into chambers underneath the piezo elements (marked by orange lines).
  • Here is a color-coded diagram of how the printhead is built. The only difference is that there 3 ink nozzles in a row instead of over 40.

  • Ink flows from the cartridge into the printhead through the red circles.

  • Ink flows into chambers underneath the piezo elements (marked by orange lines).

  • Individually addressable piezo elements for each nozzle cover the ink chambers.

  • The piezo elements are connected to a common ground by metal strips.

  • (Second image) The ribbon cable (shown as a blue overlay) connects the other terminal of all the piezo elements to the multiplexer.

Add Comment

Image 1/1: The red rectangle (behind the orange) is the ink inlet.
  • Here is another view. The gray area in the middle is the ink chamber.

  • The red rectangle (behind the orange) is the ink inlet.

  • The orange rectangle is the piezo element.

  • The green rectangle is the opening in the bottom that acts as the nozzle.

Add Comment

Image 1/3: The action starts in the second picture. Image 2/3: The ink inlet fills the chamber with ink (yellow). Image 3/3: The ink is prevented from exiting the nozzle by surface tension.
  • Let's answer your last question about the printhead now: How does it print?

  • The action starts in the second picture.

  • The ink inlet fills the chamber with ink (yellow).

  • The ink is prevented from exiting the nozzle by surface tension.

  • (Third image) When the printer needs to print, electrical current is applied to the piezo element which expands, creates pressure, and forces a single drop of ink out of the nozzle.

  • The (microscopic) drop of ink falls on the paper.

  • The contraction of the piezo element causes the remaining ink in the nozzle opening to be sucked back into the chamber.

  • Keep in mind that this printer has to control over 240 piezo elements which move over the paper many times in the time it takes to print a single page.

Add Comment

Image 1/1: The ink cartridges are very easy to replace (as they should be).
  • It is hard to give a bad repairability score to this device, because only one part of it will need to be replaced.

  • The ink cartridges are very easy to replace (as they should be).

  • The entire assembly is held together by one screw.

  • The actual print head is very delicate and is too small to be repaired, so if it breaks the entire printer will have to be replaced.

  • Update: I have now granted a repairability score to the Epson Stylus 820 Photo printer.

Add Comment

jrw01

Member since: 08/22/2013

825 Reputation

23 Guides authored

One Comment

Wow THIS IS A VERY GOOD ARTICLE. MUCH LOVE

free2rhyme17 - Reply

Add Comment

View Statistics:

Past 24 Hours: 1

Past 7 Days: 18

Past 30 Days: 105

All Time: 4,166