taskalfa 250ci

[gdisc54]

I removed all the drums and devs in the machine to vacuum them when I put everything back in, the machine throws a c7903 code. I swapped the magenta drum unit to a different spot still get the same code. I tried the drum unit in another machine had no problems, I also tried the sub front pcb in another machine and it worked fine. I have unplugged all connections to the engine pwb and reconnected them still get the code. the machine does not start to cycle before the code throws and will for a second show ready to copy before the code returns also code will only clear if I run 906. Can anyone suggest what I did to cause this code. I have retraced all my steps to no avail. the machine has the current firmware installed,I have also checked continuity from pins 14,15,16,and 17 on sub front pcb to pins 1,2,3,and 4 of the engine pcb.

[blackcat4866]

You've certainly put a lot of thought into this.

I've had a few bad drum EEPROMs but only on new units, not after cleaning. Is it possible that you bent a connector pin on the sub-front PWB? Or maybe a loose wire in the drum EEPROM connector?

It seems like you've already ruled out the drum unit and the sub-front PWB ... and the harness. The only thing left is the engine PWB.

I don't see how you could have caused this problem ... let me ask you this: Did you keep the machine plugged in while vacuuming? It's important to have a good frame ground while vacuuming the main body of the machine. Otherwise any developer vacuumed up can build up "tribo-electric effect" aka static electricity. This could damage an EEPROM or board.
=^..^=

[Venom]

You say it has current firmware, did you try re flashing it again? I had same issue once when I put c3232e firmware on a c4035e.

[gdisc54]

Yes the machine was unplugged and turned off before I started the cleaning. I did reload the firmware, but the issue happened before I loaded current firmware. A new symptom that I am now seeing is all the drum serial numbers now match the transfer belt unit serial number and all drum counts and drive time are showing 0. I have also inspected the drum and dv unit connector wires and do not see any bare wires. The hotline is telling me to replace all 4 drums ,dev's and transfer belt unit because they say the drum numbers won't be correct w/out new units. The transfer belt unit was replaced recently so hopefully their suggestion will solve my problem. thanks to all who replied to this post because we all know the hotline does not always know what we see in the field as techs. If this solves my problem I will post a thread saying so. If until then anyone else has any suggestions please post and I will keep monitoring this site thanks again all.

[blackcat4866]

I don't see how you could have caused this problem ... let me ask you this: Did you keep the machine plugged in while vacuuming? It's important to have a good frame ground while vacuuming the main body of the machine. Otherwise any developer vacuumed up can build up "tribo-electric effect" aka static electricity. This could damage an EEPROM or board.
=^..^=

I think you missed the point. Off, yes sure. Unplugged, never! You need the frame ground. If you unplug the machine where will the frame ground come from? Your fingers? The plastic wheels? The moisture in the air? =^..^=