Error message 993, what is this?

That is a fuser drive error on printers. it is the part that fixes the ink to the paper.
i have a check for you but is not an easy fix.
if fuser drive is gone will cost approx £12 to replace.

Fuser Drive and Contact Cam System Service Check
Error Code 993: Indicates the cam sensor has not been activated.
The sensor activates when the fuser drive motor turns the cam disk.
If the fuser drive motor does not turn on, or the drive parts are not
operating, go to A.
If the fuser drive motor turns and appears to be operating properly,
and the cam is turning, go to B.
If the fuser drive motor turns and appears to be operating properly,
and the cam is not turning, go to C.

A The fuser drive system is not operating properly.
FRU Action
1 Fuser Assembly
Fuser Drive Motor
Fuser Motor/Paper
Feed Motor Carriage
Unit Motor Cable
Engine Board
Check the fuser assembly internal drive gears
for binding, or broken or worn teeth. If a
problem exists, repair or replace the fuser
assembly.
Remove the fuser drive motor from the stay
assembly, leaving the motor cable connected
to the motor. Turn the printer on, but do not
allow the motor to touch other areas of the
printer. Verify the motor turns during POR. If it
does, the problem is most likely in the motor
mounting stay assembly. Go to step 2.
Check the motor for shorts between the case
and each motor winding. If a short is found,
replace the motor.
Note: Damage to the engine board may result
from a shorted motor.
Check the motor for open windings. If found,
replace the motor.
Check continuity of the fuser motor/paper feed
motor/carriage unit motor cable.
• If incorrect, replace the cable.
• If correct, replace the engine board.
2 Motor Mounting Stay
Assembly
(Fuser Drive Parts)
Check the fuser drive gears, gears C3-1, C3-
2, the clutch spring, motor drive gear, gear C2
and C4 for signs of chipped gear teeth, worn
parts, or improper operation. If problems are
found, repair as necessary.
Check the cam gears and solenoid for proper
operation and signs of broken or worn gear
teeth or damaged parts. If found, repair or
replace the motor mounting stay assembly.

B The fuser drive system is operating properly and the cam disk is
turning.
FRU Action
1 Cam Sensor (PH16)
Engine Board (M4)
SN Cable
Be sure the cam sensor is mounted correctly
and locked into place.
Check the following voltages on the cam
sensor:
Pin # Signal Voltage Voltage
Voltage Disc in Disc Out
1 (Orange) +5 V dc +5 V dc +5 V dc
2 (Brown) -CCSENS +5 V dc 0 V dc
3 (Green) GND 0 V dc 0 V dc
Note: The voltage on pin 2 should vary, as the
cam turns from approximately 0 V to +5 V dc.
• If the voltage on Pin 1 is incorrect, check
the cable. If incorrect, replace the cable.
• If the cable is good, replace the following
FRU's in the order shown:
1.Cam sensor
2.Engine board
3.SN cable

C The fuser drive system is operating properly and the cam disk is
not turning.
FRU Action
1 ContactCam
Solenoid
CRF Cable
Engine Board
Check the solenoid for proper operation,
making sure it picks during POR cycle.
Disconnect the solenoid and check the
resistance on the solenoid cable. It should
measure approximately 65 ohms. If incorrect,
replace the solenoid.
Check the voltages on the solenoid cable
connector.
Check the following voltages on the contact
cam solenoid cable connector:
Pin # Signal Voltage Voltage
Voltage Static Picked
1 (Red) +24 V dc +24 V dc +24 V dc
2 (Black) -SL2ON +24 V dc 0 V - +24 V dc
Note: All voltages are approximate.
If the voltage on Pin 1 is incorrect, check
continuity of the CRF cable to the cam
solenoid.
• If incorrect, replace the cable.
• If correct, replace the engine board.
2 Motor Mounting Stay
Assembly
Check the clutch spring, clutch boss, clutch
disk and gear C4 for signs of wear, broken
teeth or binds. Repair or replace the motor
mounting stay assembly if a problem is found.

Normaly the fuser is not turning - check the cleaner pad is not jammed in too tight. Then replace the fuser drive block 12G1348.