Epson CSIC Board Replacement Guide: 41-42V on Pin 1, "Ink Out" Errors, and When You Need an Overwrite Board vs OEM

Question: I'm trying to replace my CSIC board, but I want to confirm whether I also need to replace the motherboard. I'm measuring about 41 volts going to pin 1 on the CSIC board, and I believe it fried my current CSIC board because the CSIC LED won't turn on and I'm getting an "ink out" error. I tested the motherboard by itself (only power supply and power button connected), and the pin that matches the ribbon cable (I think pin 13 on the motherboard) still reads about 41 volts. Does that mean my motherboard is bad too, and what parts do I actually need?

Answer:

1) First: 41-42 volts on the CSIC power line is common (and it can fry boards)

What you're seeing-~41V to pin 1 of the CSIC board-is typically not "random voltage leakage." On many Epson-style DTF/DTG conversions and certain Epson platforms, the CSIC circuit is fed by a high-voltage rail (commonly ~42V). Depending on your meter, load, and the power supply's regulation, it may read anywhere around 40-42V.

So yes:

• Seeing ~41-42V on the CSIC feed can be normal for the system design.

• It also absolutely can fry CSIC boards (OEM or third-party) if there's a short, a bad connection, reversed orientation, bent pins, conductive ink residue, or a weak component on the board.

That matches your symptom: CSIC LED not lighting + "ink out" error. When the printer can't communicate with the chip system, many Epson-based platforms interpret it as missing/invalid cartridges and throw an ink-related fault.

2) Do you need an OEM CSIC board or a third-party overwrite board?

This is the most important decision, because the parts you need depend on which route you choose.

Option A: OEM CSIC board route (traditional chip-reading system)

If you want the printer to behave like a more stock configuration:

• You'll need an OEM CSIC board

• You'll need the CSIC pins (the spring contact pins that read the chip)

• You'll need cartridges that have valid chips, either:

  • OEM cartridges, or

  • third-party cartridges that include proper chips

If any one of those pieces is missing or not making good contact, you can get:

• Ink out / cartridge not recognized errors

• No CSIC LED activity

• Intermittent cartridge detection issues

Option B: Third-party CSIC overwrite board route (bypass chip-reading)

If you use a CSIC overwrite board, the goal is to eliminate the need for the CSIC chip-reading hardware entirely. In that setup:

• You typically do not need the OEM CSIC board

• You typically do not need CSIC pins

• You typically do not need cartridges with functional chips

• The overwrite board "reports" cartridge/chip presence back to the mainboard

Here's an example of the type of overwrite board you referenced:

• Epson R1390 Cartridge Chip CSIC Overwrite Board (https://bchtechnologies.com/products/epson-r1390-cartridge-chip-csic-overwrite-board-for-dtf-uv-and-dtg-printers-auto-reset-ink-level?_pos=6&_sid=ef63cb7d0&_ss=r)

Why this matters for your case:
If you're repeatedly losing CSIC boards, the overwrite approach can reduce the number of failure points in the "chip detection" chain. That said, the overwrite board is still exposed to that same ~42V environment, so good wiring and clean, dry, properly-seated connectors still matter.

3) Does measuring 41V on the motherboard pin mean the motherboard is faulty?

Not necessarily.

Here's the key concept: Voltage present ≠ motherboard is bad.
That 41-42V rail can be generated by the power supply and routed through the motherboard to the CSIC connector. If you measure it at the motherboard connector with the CSIC disconnected, you may still see the full voltage because:

• There's no load pulling it down

• The rail is simply "available" at the connector

So your reading of ~41V at the motherboard side (your pin 13 estimate) does not automatically prove the motherboard is defective. It can simply confirm the board is still receiving and distributing the HV rail.

What would more strongly suggest a motherboard problem is if you see:

• Burn marks, carbon tracking, or melted connector housing near the CSIC header

• A short-to-ground on the CSIC power rail (very low resistance) that remains even with everything unplugged

• The printer failing to boot or failing self-checks even when the chip system is bypassed correctly

• Unstable voltage (wild fluctuation) under load or signs of the rail collapsing when connected

4) Why CSIC boards commonly fail in these setups

Since you already suspect the 41-42V fried the board, here are common real-world reasons CSIC boards die repeatedly:

• Pin misalignment / bent CSIC pins causing shorting

• Conductive ink mist or cleaning fluid residue bridging pads or pins

• Ribbon cable damage (cracked traces, exposed conductors)

• Loose connector fit causing arcing or intermittent contact

• Grounding issues (static discharge is brutal on small boards)

• Shorts inside the cartridge bay area (especially in conversions)

The frustrating part is: the system can run for a while and then fail suddenly, because contamination or a slightly loose connector gradually worsens until it crosses the line.

5) What you likely need next (based on your goals)

• If you want to stay OEM-style: plan on OEM CSIC board + CSIC pins + chipped cartridges (OEM or compatible).

• If you want to simplify and avoid chip hardware: consider a CSIC overwrite board, which generally eliminates the need for an OEM CSIC board, pins, and chipped cartridges.

And yes-~42V in that circuit is a known reality, and it does fry boards more often than people expect, especially when there's any contamination or connector issue.

Addressing printer issues can be a complicated affair due to the hands-on nature of the problems, especially when electrical readings and board-level failures are involved. For that reason, we're not able to provide remote troubleshooting, suggestions, or support for printer repairs. We do offer an in-person evaluation and repair service via our local diagnostic facility: printer repair service (https://bchtechnologies.com/printer-repair-service). Due to high demand, we operate on a first-come, first-served basis, so it may take a few weeks before we can schedule time for you to drop the printer off. Our services are structured to repair either a full printer or specific parts, with clear instructions on how to proceed. That said, we recognize our rates aren't the most economical. Therefore, we strongly recommend self-help through online research. You can start by checking out YouTube-especially our channel homepage here: BCH Technologies on YouTube (https://youtube.com/@bchtechnologies). To find the most relevant content, use the search icon next to "About" on the right-hand side of the menu bar. I receive dozens of requests daily asking which video covers a specific issue, and after creating videos over the past nine years, it's hard to remember every single one-so YouTube's search tool is the quickest way to locate the best match. It may also recommend helpful videos from other creators based on the same symptoms.

Thank you again for reaching out and for supporting BCH Technologies. I hope this clears up why you're seeing ~41-42V, what it does (and doesn't) imply about the motherboard, and how to choose between an OEM CSIC setup versus an overwrite solution.