Ricoh Copier SC665 Code Troubleshooting: Inter-Board Communication Error Troubleshooting Guide
When a Ricoh copier displays the SC665 error code, the core cause is a communication interruption between the various control boards within the machine. This involves key components such as the BCU board, imaging IOB board, paper transport IOB board, image board/IPU, and the flexible flat cable (FFC) and connectors connecting these boards. The following are specific troubleshooting steps and solutions:
Ⅰ. Core Logic of the SC665 Code
SC665 is an “inter-board communication error”, meaning signal transmission between the main control board (BCU) and other functional boards (such as the IOB board and image board) fails. The machine operates through multiple boards, and any failure or disconnection on any board will trigger this error.
II. Step-by-Step Troubleshooting and Solutions
1. Prioritize checking the flexible flat cable (FFC cable) and plug.
Poor contact in the connecting cables is the most common cause of communication errors. Key inspections include:
Locate the critical cables:
Open the side or rear cover of the machine and locate the flexible flat cable (typically a white or gray flat cable with black plugs at each end) that connects the BCU board to the imaging IOB board, paper transport IOB board, and image board.
Physical inspection of the cables:
Inspect the cables for creases, breaks, frayed edges, or oxidized pins (FFC cables are prone to internal breakage due to frequent removal or aging). If damaged, replace them with new cables of the same specification.
Check the plug for looseness: Gently unplug the plug, wipe the metal contacts with an eraser to remove any oxidation, and then re-insert (ensure the plug is fully engaged and not loose or skewed).
Check the cable routing:
Ensure the cables are not pinched or tangled by the machine casing, or rubbed against metal parts. Adjust the cable to a naturally relaxed position to avoid physical interference with signal transmission.
2. Troubleshooting the Imaging IOB Board and Paper Transport IOB Board
The IOB board (input/output board) is responsible for signal transmission between specific functional modules. Failure will directly interrupt communication:
Imaging IOB Board Inspection:
The imaging IOB board is typically located near the developing or fixing system and is responsible for transmitting imaging-related signals.
Appearance Inspection: Check for bulging onboard capacitors, burnt chips, or loose solder joints. If any physical damage is detected, replace the board.
Replacement Test: Replace the imaging IOB board with a functioning one from the same model machine. If the error code disappears after replacement, the original board is confirmed to be faulty.
Paper Transport IOB Board Inspection:
The paper transport IOB board is located near the paper path and controls the paper transport signals.
Cleaning and Connections: Unplug and unplug the board connector cables and use a brush to clean dust from the board surface (dust accumulation can cause short circuits or signal interference).
Functional Troubleshooting: If the error persists after replacement, eliminate the fault in that board and continue troubleshooting other components.
3. Image Board/IPU Troubleshooting
The image board (IPU) is responsible for image processing signal transmission and is directly related to scanning and printing functions.
Location and Inspection:
The image board is usually located in the middle or rear of the machine, connecting the scanning unit and the BCU board.
Check whether the heat sink on the board is loose and whether the chip is overheating (an abnormal temperature after powering on may be a sign of a fault).
Reseat the cable connecting the board and the BCU board to ensure tight contact.
Replacement Test:
If there are no visual abnormalities, replace the image board with a functioning one and test again. If the code disappears, the original image board is faulty and needs to be replaced.
4. BCU (Main Control Unit) Troubleshooting
The BCU board is the core control board of the machine. If other boards and cables are normal, inspect the BCU board:
Basic Inspection:
Check the BCU board for liquid leakage, insect damage, or damage to the connector (such as bent pins).
Power Supply and Signal Test:
Enter maintenance mode and use the “5990” code to check the inter-board communication status (this code may vary depending on the model). If the BCU indicates communication with other boards is interrupted, first check whether the BCU board’s power supply circuit is functioning properly.
Replacement Verification:
Due to the high cost of replacing a BCU board, it is recommended to confirm the fault by replacing it with a functioning BCU board of the same model. Once confirmed, replace the new board and reconfigure the machine parameters.
III. Troubleshooting Precautions
Power-off Operation: All boards and cables must be inspected with the power off to avoid electric shock or burns.
Static Electrostatic Discharge Protection: Before handling a board, touch the metal casing to release static electricity to prevent damage to the chip.
Model Matching: When replacing a board, ensure the model is identical (different models may have different interfaces or functions, which may cause new faults).
IV. Preventative Recommendations
Clean the interior of the machine regularly to prevent dust and paper debris from accumulating and causing short circuits on the boards.
When transporting or repairing, be careful when disassembling and loading to avoid pulling on the FFC cables, which could cause breakage.
Install a dehumidifier in humid environments to reduce the risk of board oxidation.
Summary:
The root cause of SC665 communication errors can be effectively identified by troubleshooting in the following order: cable → IOB board → graphics board → BCU board. In most cases, cleaning the cable connector or replacing a damaged cable can resolve the issue, minimizing the likelihood of board failure.
If the problem is still not solved after referring to the above, you can leave a message in the comment area.
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