def main(): parser = argparse.ArgumentParser(description="Epson EEPROM Dump Patcher + CRC Fix") parser.add_argument("input", help="Input EEPROM dump (.bin file)") parser.add_argument("-o", "--output", help="Output patched dump file") parser.add_argument("--model", default="generic_24c08", help="Printer model (L805, L3110, XP-4100)") parser.add_argument("--analyze", action="store_true", help="Only analyze, don't patch") parser.add_argument("--reset-waste", action="store_true", help="Reset waste ink counters to 0") parser.add_argument("--region-free", action="store_true", help="Patch region to free mode") parser.add_argument("--set-serial", help="Set new serial number (max 16 chars)") parser.add_argument("--force-crc", action="store_true", help="Fix CRC after patching")
args = parser.parse_args()
if not os.path.exists(args.input):
print(f"[-] File not found: args.input")
sys.exit(1)
with open(args.input, "rb") as f:
data = bytearray(f.read())
cfg = KNOWN_CONFIGS.get(args.model, KNOWN_CONFIGS["generic_24c08"])
if args.analyze:
analyze_dump(data, args.model)
return
# Apply patches
if args.reset_waste:
off, wlen = cfg["waste_ink_counter"]
data = reset_waste_ink(data, off, wlen)
if args.region_free and "region_offset" in cfg:
data = patch_region_free(data, cfg["region_offset"])
if args.set_serial and "serial_offset" in cfg:
data = patch_serial(data, cfg["serial_offset"], args.set_serial)
# Fix CRC if requested
if args.force_crc:
crc_start, crc_end = cfg["checksum_range"]
crc_pos = cfg["checksum_pos"]
data = fix_eeprom_checksum(data, crc_start, crc_end, crc_pos)
print(f"[+] CRC recalculated and written at 0xcrc_pos:X")
# Write output
out_file = args.output if args.output else args.input + ".patched"
with open(out_file, "wb") as f:
f.write(data)
print(f"\n[✔] Patched dump saved to: out_file")
print("[!] Warning: Use on hardware only if you understand the risks (warranty void).")
if name == "main": main()
Before understanding the "patch," you must understand the "dump" and the "chip."
EEPROM (Electrically Erasable Programmable Read-Only Memory) is a tiny, non-volatile memory chip found on your Epson printer’s main logic board. Unlike RAM, it retains data when the power is off. Unlike standard ROM, it can be rewritten (flashed) electronically. eeprom dump epson patched
def reset_waste_ink(data: bytearray, offset: int, word_len: int = 2) -> bytearray: """Zero out waste ink counters (main and backup).""" # Typically two words (main + backup copy) for i in range(word_len): data[offset + i2 : offset + i2 + 2] = b'\x00\x00' print(f"[+] Waste ink counters reset at 0xoffset:X") return data
def patch_region_free(data: bytearray, offset: int) -> bytearray: """Change region to 'FREE' (0x00) or 'WW' (worldwide).""" data[offset:offset+2] = b'\x00\x00' print(f"[+] Region patched at 0xoffset:X") return data
def patch_serial(data: bytearray, offset: int, new_serial: str) -> bytearray: """Inject custom serial number (padded to 16 bytes).""" serial_bytes = new_serial.encode('ascii')[:16] serial_bytes = serial_bytes.ljust(16, b'\x00') data[offset:offset+16] = serial_bytes print(f"[+] Serial changed to new_serial") return data def main(): parser = argparse
The patched EEPROM file was flashed back to the printer using the service utility's "EEPROM Restore" function.
Eson printers utilize non-volatile EEPROM (Electrically Erasable Programmable Read-Only Memory) to store configuration data, serial numbers, and usage counters. Unlike user-configurable settings, usage counters like the waste ink pad level are usually read-only or protected by the firmware to prevent tampering.
When the counter reaches a manufacturer-defined threshold, the printer enters a lockout state. Standard software reset tools (WIC tools) require a paid key to reset this. This write-up documents a manual patch of the EEPROM dump to bypass this requirement for diagnostic purposes. if name == " main ": main()
There are three legitimate (and two not-so-legitimate) reasons why someone would seek an EEPROM dump for an Epson printer.
The internet is flooded with broken printers due to bad patched dumps. Here is the reality: