L805 Printhead Pinout: How to Identify Pins Using an L1800 Conversion Board

Question:
I watched your video "About Good or Bad? Testing a L1800 Printhead with Multimeter Revealed!" and wanted to know if you have a pin diagram for the Epson L805 printhead.

Answer:

Regarding the Epson L805 printhead pin diagram, unfortunately I haven't created a dedicated pinout diagram specifically for the L805 head. However, there is still a practical way to work around this.

The Epson L805 and Epson L1800 printers share very similar printhead architecture, as both belong to Epson's MicroPiezo platform. Because of this similarity, technicians often refer to L1800 documentation or test procedures when diagnosing L805 printheads.

One helpful reference is the L1800-to-L805 conversion board used in DTF or modification setups. By examining this board, you can usually trace how the pins are mapped between the two models. The conversion board essentially acts as a translator between the wiring layouts, so it visually reveals which pins correspond between the L1800 head and the L805 head.

Here are some tips if you are trying to identify or test L805 printhead pins with a multimeter:

1. Understand the pin groupings
Most Epson printheads have pins divided into several groups, including:

• Nozzle drive pins - control firing of ink channels

• Ground pins - shared ground lines

• Temperature sensor pins - used by the printer to monitor head temperature

• ID or detection pins - identify the printhead type

These groups are often arranged in clusters on the FFC connector.

2. Use the L1800 as a reference
Since the L1800 and L805 heads are closely related, the L1800 pin test method demonstrated in the video can often be applied to the L805 as well. By comparing the traces on a conversion board or mainboard connector, you can determine which pins correspond.

3. Checking for short circuits
When testing with a multimeter in resistance mode:

• Check between adjacent nozzle driver pins

• Look for consistent resistance patterns across channels

• A reading close to 0 ohms may indicate a shorted driver circuit

• An open circuit where others show resistance could indicate a damaged firing line

These tests help determine whether the printhead electronics are intact.

4. Be careful during testing
Printhead circuits are extremely delicate. When probing:

• Avoid slipping with the multimeter probes

• Never apply voltage directly to the pins

• Always disconnect the head from the printer before measuring

Accidentally bridging pins can permanently damage the head or the mainboard.

5. Trace the conversion board
If you can access an L1800-to-L805 conversion board, you can follow the copper traces visually to map the pin relationships. This method often provides enough information to determine the correct pin positions even without a formal diagram.

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