BizHub Pro C500 SC28-01 after PM

[Desert Rat]

,
Here is the back round. This machine has 35K on the meter and on the
internal counters. The condition of the drums, chargers, dev, and
transfer belt look like they have closer to 100K. The copy also looked
that way. Not good.
This machine is one of three in the shop. I need to get it ready for next
week, it has been sold. The other two units have much higher meters
700K and 900K. The counters on these parts read about 6-8K and the
parts look like that is all is on them. So I put them in the unit with the
low meter, all at once. All from the same machine. I was doing the
adjustments when the code appeared. First I ran Initial drum rotation,
then auto color registration. That's when the code popped up.
I tried putting the old drum and charger back, but that was no help.
I also put another drum from the other unit in, no help.
I noticed that the drums were coated with toner on the transfer side.
I did clean the machine with compressed air. Just lite puffs from about
12-18 inches away, then wipe.
If I let this unit power up to copy it also gives the code.
The machine with the old looking parts stills fires up and make a copy.
A bad copy but no codes.

I'm still green on this model and could use some pointers.

Thanks

DR

[laserman06]

Every time I have had that code it turned out to be the drum potential sensor.
Swap the yellow drum potential sensor(both sensor and board) with another color's. You mentioned that you cleaned the machine with compressed air. Did you clean the drum potential sensors? I have blown a couple of them, before switching to a small blower brush. Gentle puff. No more blown sensors.

Hope this helps.

SC28-01, SC28-02, SC28-03 or SC28-04 code.
Solution
CAUSE: Abnormal charge. Related codes to colorsare as follows:
28-01 = yellow
28-02 = magenta

28-03 = cyan

hub PRO C500 Warm-up, wrong display, incorrect operation, lock-up

28-04 = black
SOLUTION: In order, perform the following:
Switch Charge Corona with one of another color.
Change indicated color Charge Corona wire.
Switch Drum Potential Sensor (p/n 65AA-2282) with one of another color.
If the problem persists, replace HV-1 (p/n 65AA 8401 0).
Note : The Parts Catalog (page 99, REF NO. 9) lists the Drum Potential Sensor as the HV detecting sensor assembly. The assembly comes with the board,
rail, sensor and wiring.

[Desert Rat]

, Thanks for the reply Laserman06,
I almost did that yesterday but was not sure if the top of the process unit
would come off the top rail. I will look into just removing the plastic piece
under it.

Thanks again, and if anything else comes to mind please post

DR