L805 Printhead Issues with BCH Conversion Board and Breakout Board: Common Problems and Fixes

Question:

I have an L805 printhead with the BCH conversion board & breakout board connected. The printhead only activates when you connect both boards. How do I fix this?

Answer:

As far as your issue with the L805 printhead, it’s a matter of closely examining the connection between your BCH conversion board/breakout board and the printhead. There are a couple of reasons that could be causing the problem you are facing:

Primary I/O pin: It's also possible that the primary I/O pin is tied to some other process on the breakout board, preventing the print head from sourcing the necessary voltage. Certain breakout boards modify the signal transfer between the printhead and the printer’s mainboard. Now, the printhead only works when the breakout board is used, as the board potentially corrects the proper signal and is removed.

Loose or faulty connection: Loose or misaligned connections can cause some printer functions to act erratically internally. Inspect all wiring and ribbon cables to be correctly seated and aligned. One common issue may be a cable that is simply not all the way plugged in or a ribbon cable displaced just a bit, causing the printhead to not get the signals it needs to work.

Firmware or Board Compatibility: You could also have a compatibility issue between the printer’s firmware and the conversion or breakout board. If the printer’s firmware is looking for a specific signal or connection, the printhead's lack of response might make it think it is non-functional unless the breakout board is attached. Make sure the firmware on your printer supports the setup you are using, and see if any firmware updates can help resolve compatibility problems.

Conversion Board Setup: The other area to check is the BCH conversion board. Confirm whether the board is appropriately installed and providing the correct power and signal output to the printhead. The same misconfigured conversion board would prevent the printhead from working at all unless both boards were physically plugged into the printhead.

Printhead dependent on breakout board: The breakout board may change the circuit so the printer needs it to make the printhead run. Trying a direct connection without the breakout board and seeing if the printhead reacts will also be helpful. This will help you determine whether the breakout board interrupts the operation or is needed for the correct operation.

Troubleshooting Steps:

Here are a few things you can do to troubleshoot the issue:

Test without breakout board: Take a different base if the Input pin shows an error.

Measuring voltage outputs: Measure the voltage outputs on the BCH conversion board and the breakout board. Ensure the printhead is getting the correct voltage to function correctly.

Check custom wiring: During your troubleshooting setup, look for any broken paralleled or destroyed connections in your custom wiring system.

Try another ribbon cable if a defective one can sometimes produce intermittent failures. Try swapping it out to eliminate a bad link.