Based on the model numbers given, you have an imageCLASS MF4350d. If the error light is solid, you'll want to first confirm if an error message or code is displayed in the LCD that requires attention or any steps to be taken (Ex: Paper Jam; Low Toner).
However, if an error message or code is not displayed, a process of elimination will need to be performed to determine the cause of the error light:
1. Try pressing the <Stop/Reset> button and wait 1-3 minutes without pressing any additional buttons. This will allow your laser product to adjust and then respond.
2. Check all areas of your machine to remove any jammed paper: Automatic Document Feeder, inside and under toner cartridge; Cassette or Multi-purpose Tray, Rear Panel. If an obstruction is removed, reset the machine's power for 30 seconds to clear the error.
3. Disconnect the USB cable, telephone cord(s) and power cord from your machine. Wait 1 minute. Then, only reconnect the power cord. Check to see if the error light returns.
4. If the menu is accessible, please try the following to check and clear the Status Monitor of any pending jobs in memory on the unit to further isolate the cause of the issue. Check the following: TX/RX Status, TX/RX Log, Print Status, Report Status. To access: Press <Status Monitor/Job Cancel>; then use < or > to scroll to each status area, make selection to cancel job, and press <OK>.
5. Unplug the unit again for 10 - 30 mins. to fully reset. If your product is plugged into a surge strip, please connect directly to a known working wall outlet to confirm full power is being received.
Note: If the unit is in a room that is very cool, cold or has humidity, please try testing the unit in a different room.
If unresolved or a specific error code is being displayed, please Contact Us for further assistance.