Troubleshooting information on the Kyocera FS2000D Error Code C6030 Fuser Fault
Really, there isn’t a whole lot to say on the  Kyocera FS2000D Error Code C6030 Fuser Fault. The error means that the fuser detected a problem with the thermistor M wire. If you decide you want to purchase a replacement fusing assembly you can find a link to order it below. If you need the illustrated replacement instructions then you can find those at the bottom of the article.
Kyocera FS2000D FK-310 Fuser Unit – 120 Volt
Kyocera FS2000D Error Code C6030 Description
Broken fuser thermistor M wire
30/31 ppm printer (EUR/USA model):
Input from fuser thermistor M is less than 1 (A/D value) for more than 1 s.
–
Service Manual Troubleshooting Information for the Error Code C6030
1. Poor contact in the fuser thermistor M connector terminals.
Reinsert the connector.
2. Broken fuser thermistor M wire.
Measure the resistance. If it is ∞ Ω, replace the fuser thermistor M.
3. Fuser thermistor M installed incorrectly.
Check and reinstall if necessary
4. Thermal cutout triggered.
Check for continuity. If none, replace the thermal cutout.
5. Fuser heater lamp installed incorrectly.
Check and reinstall if necessary
7. Broken fuser
heater lamp wire.
8. Check for continuity. If none, replace the fuser heater lamp.
If you feel the need to replace the fusing assembly or if you want to remove it to test various parts of it then click on the link below for the removal instructions.
—  Kyocera FS2000, FS3900, FS4000 Fuser Replacement  —
Lexmark MS810dn MonochromeLaser Printer, Network Ready, Duplex Printing and Professional Features
Price: $1,499.99
10 used & new available from $478.99
Lexmark MS610dn Monochrome Laser Printer, Network Ready, Duplex Printing and Professional Features
Price: $1,099.00
9 used & new available from $299.99