Ricoh “SC672” — controller/engine communication error — field-proven fixes
Joe B.
Expert ★★★★★ 27,853 satisfied customers
Specialities: Ricoh MP/IM series, Laser printers, DC/BICU boards, Firmware, Network print
Fix Ricoh SC672 — controller/engine comms fault (BICU, IOB, harness, NVRAM, firmware)
Technician
Quick triage: Which model (e.g., MP C4503/MP 2555/IM C3000)? Does SC672 appear at power-on, right after a paper jam, or after a power outage/firmware update? Any recent moves, optional units (fax/finisher), or network changes?
Technician
We’ll do a clean power reset, reseat the engine cables, isolate options, and, if needed, update firmware or initialize NVRAM (safe method) before considering board replacement.
Technician
1) Power off with the main switch. Unplug for 2 minutes to discharge.
2) Disconnect non-critical options (fax, finisher/bridge, extra trays, HDD/SSD if modular). Boot with the base engine only. Many SC672 cases are caused by an option shorting the engine I/O bus.
3) If it boots, reconnect options one by one.
If SC672 persists, we’ll reseat controller & BICU connectors next.
Technician
• Remove left/rear covers to access the controller (main board/IOB) and engine/BICU boards.
• Unplug and firmly reseat the ribbon/LVDS and multi-pin engine harness between controller ↔ BICU. Look for bent pins, partially seated plugs, or toner dust/oil on contacts.
• Verify grounds: metal tabs/screws from BICU to frame must be tight; poor ground = intermittent engine communication.
• Check harnesses to the OP panel and PSU too; low 5V can trigger SC672 at panel init.
Technician
• Try a forced firmware update from USB/SD (engine + system packages). If the device won’t reach ready, many models still accept recovery firmware at early boot.
• If SC672 started after a power loss, the NVRAM may be inconsistent. Enter SP mode and run the NVRAM clear (engine only / partial) option — this resets comms tables without wiping counters. We’ll guide the exact SP path for your model in chat.
• If the panel cannot enter SP, recovery firmware is the safer next step.
Technician
• If the device boots further with options removed and harness reseated, the BICU/DC controller is often the culprit.
• If network/print works briefly then crashes at panel init, suspect the controller (IPU/IOB) or storage (HDD/SSD).
• Measure PSU rails (5V/24V) under load; drops cause random SC672 at warm-up.
• Tech tip: swapping in a known-good BICU is faster than replacing the controller first on MP/IM engines.
Technician
• Don’t hot-plug boards; always power off and unplug first.
• Avoid full NVRAM/engine data clears unless we’ve backed up necessary values (calibrations, counters).
• Don’t spray contact cleaner on ribbon cables — use a dry, lint-free wipe only.
• If the machine had a surge, inspect the PSU and fuses before repeatedly powering on.
Technician
• Update to the latest system/engine firmware for your model.
• Replace any chafed harness to the finisher/bridge; secure with cable ties so jams don’t tug the connector.
• Ensure fans spin freely and the low-voltage PSU outputs are stable (5V within spec).
• If you re-enable the option and the error returns, the option’s PCB is faulty — run without it or replace that unit.
Technician
Quick answer: the accepted fix
Accepted fix when Ricoh shows SC672: power off/unplug, remove optional units, reseat the controller–BICU cables, verify grounds and PSU voltages, then update engine/system firmware or run a partial NVRAM reset. If still present, replace the suspect BICU/DC controller or main controller board.
What causes Ricoh SC672 (controller ↔ engine comms)?
SC672 indicates the system controller can’t hand-shake with the engine/DC controller (BICU). Triggers include loose IOB harness after clearing a jam, oxidized connectors, failing low-voltage PSU, corrupted NVRAM after a power event, or firmware mismatch between engine and system. On MP/IM series, a faulty option (fax/finisher/extra tray) can also pull the bus low and generate the error.
How to verify the repair worked
Boot to ready state, print a configuration page, then several test prints from PC. Power-cycle the device to confirm the error doesn’t return. Reattach options one at a time. If SC672 reappears after adding a unit, that option’s PCB or harness is defective.
SC672 quick checklist
Most fixes involve reseating the controller–engine harness, updating firmware, or isolating a bad option.
Quick path: full power reset → boot base engine only → reseat BICU/IOB cables & grounds → check 5V/24V → recovery firmware or partial NVRAM init → swap test BICU or controller if needed.
Disclaimer: This information is AI-generated and intended for general guidance only. For advice specific to your environment, please consult a verified expert on Whizz-Tech before making decisions.
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FAQ
What does Ricoh SC672 actually mean?
It’s a controller–engine communication error: the system controller fails to initialize or maintain a link with the BICU/DC controller. Causes include loose harness, option faults, PSU voltage issues, corrupt NVRAM, or firmware mismatch.
How do I clear SC672 without replacing parts?
Power off/unplug → remove optional units → reseat controller/BICU cables and grounds → verify PSU rails → update engine/system firmware or perform a partial NVRAM reset in SP mode.
SC672 after a jam or move — what’s likely?
Harness partially pulled or oxidized connectors on the engine I/O bus. Reseating the cables and securing them usually restores communication.
Which board fails more often?
On many MP/IM models the BICU/DC controller is more commonly at fault than the system controller, but confirm with isolation and firmware/NVRAM steps first.
| Symptom | Likely cause | Quick fix |
|---|---|---|
| SC672 at power-on | Loose controller–BICU harness, bad PSU/NVRAM | Reseat harness, check 5V/24V, partial NVRAM init |
| SC672 after clearing a jam | Connector tugged, option short on I/O bus | Boot base engine only, reconnect options one by one |
| Random reboot then SC672 | Firmware corruption or storage fault | Recovery firmware via USB/SD; check HDD/SSD |
| Returns when finisher attached | Finisher PCB or cable | Run without finisher; replace harness/PCB |
Step-by-step (Ricoh MP/IM series)
- Power off and unplug; remove optional units (fax/finisher/extra trays).
- Reseat controller ↔ BICU harnesses and grounds; inspect pins/oxidation.
- Verify PSU rails (5V/24V) and fan operation; correct any drops.
- Apply recovery firmware; if needed, perform partial NVRAM initialization.
- If unresolved, swap-test BICU then controller; replace the failed board.
Note for network environments
- SC codes are local to the device; drivers or macOS/Windows clients don’t cause SC672.
- After repair, print a config page and re-add the printer queue if needed.
Sources
Filed under: Printers
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