MX2600 L4-16 error

**harps05** · 03-02-2015

Currently have a client with a MX2600 that is displaying a L4-16 error.

Now I understand this is related to the fuser pressure release. I have had this in the past where I have replaced the sensor but this time I have tried a number of things with no result.

I have, so far, did the following:

• Replaced complete fuser pressure release motor assembly, which also contains the pressure release sensor
• Replaced the pressure release sensor in that also
• Replaced complete fuser unit with a known working one
• Checked Transfer belt for blade flip
• Checked all drum units for blade flip
• Check Transfer belt drive gear
• Replaced PCU PWB with a known working item
• Removed complete inner finisher unit

When sim6-6 is performed there doesn’t seem to be any power to the pressure release motor. If I manually close and open the fuser pressure release gear on the fuser, it is recognised in sim6-6. So it doesn’t seem to be a sensor issue.

If you could give me any pointers, it would be greatly appreciated

**ruben** · 03-02-2015

Looks like the sensor is working, so I would look at the motor side.

**igi** · 03-02-2015

If motor is not turning , Check Motor , and drive signal from Toner Motor Control PWB
clean or replace.
fuses on dc-power/check too

**blackcat4866** · 03-02-2015

I don't see Sharp very often any more, but I have it on very good authority that you need to replace the Toner Motor Driver board. This board is located above the Main Drive Unit and has a direct harness to the Fuser Pressure Drive release motor.

Parts Guide section 41, item 48.

"Have had this many times. Usually occurs when the motor harness is plugged in while the main switch is turned on (machine off at sub-power switch). Happens to the techs a lot!
Have seen it, had it myself and traced the circuit diagram to that board."

I hope this helps. =^..^=