Sc.503

[Ltd]

I am unable to find solution to fix this sc.503 .I admitted. The LCT showed this code. It attached below Mpc.4500. The Lct had 2 paper trays, left and right. Please help !

[Llama God]

Check for paper behind tray 3, including any wedged into the connector on the back.

[Shadow1]

Also had a springs break in the feed assy so the pickup roller would never lift up when it was supposed to, but paper stuck in the connectors would be much more common

[Cipher]

Fairly common error on the LCT (tandem tray).
9 out 10 times it's down to poorly stacked paper, edges sticking out everywhere causing drag as the tray lifts.

Fan and re-stack, cycle the power off / on and test.

[Ltd]

Code can be reset

Fairly common error on the LCT (tandem tray).
9 out 10 times it's down to poorly stacked paper, edges sticking out everywhere causing drag as the tray lifts.

Fan and re-stack, cycle the power off / on and test.

My customer know howto reset the SC by turning power Off then On, when I arrive, I check left+right tray mechanism, all look fines, but in SMC report, there are several times the code 503 appeared in few days. I tested feeding is fine. I ran 150 pages no code. I am just do not know where else to look for.

[cobiray]

Check the drive for the shift lever. The inner race of the gears can round out and slip or not turn at all depending on the amount of paper in the shift tray.

[Ltd]

Check the drive for the shift lever. The inner race of the gears can round out and slip or not turn at all depending on the amount of paper in the shift tray.

You meaned left tray mechanism ? I will check it out, but since new the SC503 code had appeared, this made me wonder !

[cobiray]

You meaned left tray mechanism ? I will check it out, but since new the SC503 code had appeared, this made me wonder !

Yes the left side.

You might want to check the rear paper guide on the right side also. If it's bent or deformed the tray can have trouble lowering or raising.

[techshare]

sc 503

Check tray position sensor, one time I found it got knocked out just a tad. Good Luck!

[bonnie750]

i agree with techshare...had the same thing.I reckon if paper was over the back it wouldn't come to ready atall

[techspec]

I have found that the timing pulley (AB03 0787, located on page 11- item no:25) requires replacing when this fault appears.

The gear or timing pulley as it is called in the parts manual has a flat section on it where it sits on the shaft, through time this rounds and the paper isn't transported properly from the left hand side of the tandem tray to the right.

Hope this helps. It took me a bit of time to find this fault because if you remove the stepper motor and drive the belt and pulley by hand it moves freely and visually it looks okay. But I would definatelly check out this gear.

[Ollie1981]

I have found that the timing pulley (AB03 0787, located on page 11- item no:25) requires replacing when this fault appears.

The gear or timing pulley as it is called in the parts manual has a flat section on it where it sits on the shaft, through time this rounds and the paper isn't transported properly from the left hand side of the tandem tray to the right.

Hope this helps. It took me a bit of time to find this fault because if you remove the stepper motor and drive the belt and pulley by hand it moves freely and visually it looks okay. But I would definatelly check out this gear.

I have had this problem many a time on the MP7500 where it usually flags up SC515.

The quick indicator I always use before I get the screwdriver out is to see if I can move the tandem tray rear fence by hand. The stepper motor is geared down so much that it is impossible to move by hand under normal circumstances, if the pulley gear has rounded off then the fence will move and you will see the pulley spin on the motor shaft.

[techspec]

I have had this problem many a time on the MP7500 where it usually flags up SC515.

The quick indicator I always use before I get the screwdriver out is to see if I can move the tandem tray rear fence by hand. The stepper motor is geared down so much that it is impossible to move by hand under normal circumstances, if the pulley gear has rounded off then the fence will move and you will see the pulley spin on the motor shaft.

You would think that they would make the pulley of a stronger material.
Like you I have come across it in the larger machines

[cobiray]

It's a mechanical fuse. The gear breaks before the shift lever or drive belt or something more expensive than a $2 gear.

[gary]

check the lif up motor