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What This Error Means

The 390.TONER.ERROR indicates a problem with the installed toner cartridge, its communication with the printer, or the toner dispensing mechanism.

Detailed Explanation

The OKI 390.TONER.ERROR is a critical alert signaling that the printer is unable to properly detect, communicate with, or utilize the toner cartridge. This error typically means the printer cannot confirm the presence of a valid toner cartridge, or it's encountering an issue with the cartridge's internal chip, which tracks toner levels and authenticity. It can also point to a mechanical problem preventing toner from being dispensed correctly, or a sensor issue within the printer that monitors toner presence. Common causes include incorrectly seated toner cartridges, using non-genuine or refilled cartridges that the printer's firmware rejects, a faulty toner cartridge chip, or debris obstructing the connection points between the cartridge and the printer. Less frequently, it could be an internal printer component failure related to the toner detection system or the high-voltage transfer unit that charges the toner. This error will prevent printing until resolved, as the printer cannot operate without a functional toner supply.

DIY Troubleshooting Steps

Try these steps before calling a specialist

1
Turn off the printer completely and unplug it from the power source.
2
Open the front cover and carefully remove the toner cartridge from its slot. Inspect the cartridge for any physical damage, loose parts, or protective seals that might still be attached.
3
Gently wipe the metallic contacts on both the toner cartridge and inside the printer's toner slot with a clean, dry, lint-free cloth. Ensure no toner powder or debris is obstructing these contacts.
4
Reinsert the toner cartridge firmly into its designated slot until it clicks securely into place. Make sure it's seated correctly and not tilted.
5
Close the front cover, plug the printer back in, and power it on. Observe if the error clears during the startup sequence.
6
If the error persists, try installing a brand-new, genuine OKI toner cartridge. This helps rule out a faulty cartridge as the cause.
7
Perform a hard reset: With the printer on, unplug it from the wall outlet for at least 60 seconds, then plug it back in and power it on.
8
Consult your printer's user manual for specific instructions on toner cartridge installation and error code resolution for your model.
9
Check for any available firmware updates for your printer model on the OKI support website. Sometimes, firmware updates can resolve compatibility issues with newer toner cartridges.

When to Call a Specialist

You should call a specialist if you've tried all the DIY steps, including replacing the toner cartridge with a new, genuine one, and the 390.TONER.ERROR persists. This indicates a deeper hardware issue within the printer itself, such as a faulty toner sensor, a problem with the high-voltage power supply to the toner unit, or a defective main board. These internal components require specialized tools and expertise for diagnosis and repair, and attempting to fix them yourself could cause further damage or void your warranty.

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OKI Error Code 390.TONER.ERROR