C7901 3252ci

[bush_tech]

Re: C7901 3252ci

Have the units been replaced before? Or are they the ones from the factory? If replaced and power was still on you will get this issue,and you must also run U952 at setup and any unit replacement for them to register properly

they are the machines original units

[Tonerkiller]

Re: C7901 3252ci

Did you ever fix this?

[Robbiep84]

Re: C7901 3252ci

Was this ever resolved? I am having the same issue as the original post. Exhausted all of the obvious and less obvious possible solutions. Anything "Outside of the box" I can try to get this machine running?

[PrintWhisperer]

Re: C7901 3252ci

Was this ever resolved? I am having the same issue as the original post. Exhausted all of the obvious and less obvious possible solutions. Anything "Outside of the box" I can try to get this machine running?

Failure of the EEPROM data system can come from disruption in 3.3v supply, or any connection in the serial data loop. Bent pins on the Unit connector, loosening/dmg to Relay PWB sockets, and failure of the Relay PWB serial data communications chip (on backside of PWB) have all been noted.

Front PWB (Drum/DV relay PWB) 302L794030 PARTS PWB DRUM DLP CONNECT ASSY SP (25/32ppm)
Feed Image PWB
Engine PWB

Check all +3.3v2 sources and EEPROM pulse signals. There is a set for EACH DRUM and DV, below is a sample set of signals from the Relay (Front) PWB to the Feed Image PWB. The pulse signals will be around 2v +/-.3 nominal depending on pulse rate at time of monitoring. Below 1.7-1.5v could be a comprimised (intermittent) signal.


YC1 Drum/DV Relay PWB
1 GND - - Ground
2 +3.3V2_FUSE O DC3.3V DC3.3V power output
3 DRM_EEP_SEL0 I DC0V/3.3V EEPROM select signal
4 DRM_EEP_SEL1 I DC0V/3.3V EEPROM select signal
5 EEP_SCL I DC0V/
3.3V(pulse)
EEPROM clock signal
6 EEP_SDA I/O DC0V/
3.3V(pulse)
EEPROM data I/O signal

[Fatmanpoop360]

Re: C7901 3252ci

Failure of the EEPROM data system can come from disruption in 3.3v supply, or any connection in the serial data loop. Bent pins on the Unit connector, loosening/dmg to Relay PWB sockets, and failure of the Relay PWB serial data communications chip (on backside of PWB) have all been noted.

Front PWB (Drum/DV relay PWB) 302L794030 PARTS PWB DRUM DLP CONNECT ASSY SP (25/32ppm)
Feed Image PWB
Engine PWB

Check all +3.3v2 sources and EEPROM pulse signals. There is a set for EACH DRUM and DV, below is a sample set of signals from the Relay (Front) PWB to the Feed Image PWB. The pulse signals will be around 2v +/-.3 nominal depending on pulse rate at time of monitoring. Below 1.7-1.5v could be a comprimised (intermittent) signal.


YC1 Drum/DV Relay PWB
1 GND - - Ground
2 +3.3V2_FUSE O DC3.3V DC3.3V power output
3 DRM_EEP_SEL0 I DC0V/3.3V EEPROM select signal
4 DRM_EEP_SEL1 I DC0V/3.3V EEPROM select signal
5 EEP_SCL I DC0V/
3.3V(pulse)
EEPROM clock signal
6 EEP_SDA I/O DC0V/
3.3V(pulse)
EEPROM data I/O signal

Just had this on a 4052Ci, low voltage power supply was at fault due to a toner build up on the psu.

Machine wasn't logging the error in 904. It wouldn't initialise the system in 021. So went digging and found the psu at fault

[tech07]

Re: C7901 3252ci

I am fighting this same C9701 code now. I have replaced the image pcb, the front pcb, the main drive unit and drum .I also noticed that the 117 and 984 are greyed out. Also it will not do a 021 or a 906. Engine pcb will be next, but not all that confident in it.
Anyone have fixes yet ?

[fishleg]

Re: C7901 3252ci

I am fighting this same C9701 code now. I have replaced the image pcb, the front pcb, the main drive unit and drum .I also noticed that the 117 and 984 are greyed out. Also it will not do a 021 or a 906. Engine pcb will be next, but not all that confident in it.
Anyone have fixes yet ?

We had a similar fault and to narrow it down we would just install say dev drums without belt then go into maintenance mode and see if the sn's of drum and dev would show up. We realised when ever the transfer belt was inserted it would give 7901... I've had a short on the transfer belt cause it and the connector between belt and frame on the front.

I do think kyo needs to make it easier to find shorts on these machines as it's so hard to check voltage internally with covers open. You can trace it at the back but since usually one connector splits off into about 10 it's almost impossible to work out. They could maybe add a mode that ignores all codes but supplies 24v 12v 5.5v 3.3v to everything even with door open so you can quickly find what's missing.

[PrintWhisperer]

Re: C7901 3252ci

We had a similar fault and to narrow it down we would just install say dev drums without belt then go into maintenance mode and see if the sn's of drum and dev would show up. We realised when ever the transfer belt was inserted it would give 7901... I've had a short on the transfer belt cause it and the connector between belt and frame on the front.

I do think kyo needs to make it easier to find shorts on these machines as it's so hard to check voltage internally with covers open. You can trace it at the back but since usually one connector splits off into about 10 it's almost impossible to work out. They could maybe add a mode that ignores all codes but supplies 24v 12v 5.5v 3.3v to everything even with door open so you can quickly find what's missing.

You are on the right track there, especially with the 24V supply and distribution. Usually you will have lost 24V coming off of the Image Drive PWB or Feed Drive PWB. You will find the 24V2 or 24v3 rail is missing somewhere. I have traced it to the interlock switch failure (24V2_IL) (mechnical, failure to fully actuate) or a failure in one of the PWBs.

24V2_IL becomes a distributed voltage to power much of the container area as well as the Front PWB (Drum Developer PWB).

Generally after restoring the 24v failure, you then have a TX belt or other MK part whose UART for the EEPROM data system has been blown. (Pulling the unit and looking for the MK part SN's to return in MM is the key there) Since the EEPROM data system is a serial data loop, one failure takes the whole system down. This shows up as a C7901 probably because it is the first thing the system checks. (but rarely the actual failure)

I agree tracing the 24v distribution can be tricky. There are some typo's in the manual as far as the I/O column in the PWB charts is concerned but that is still the best way.

THIS CAN HAPPEN FROM REPLACING PARTS WITH THE POWER ON, PLEASE AVOID IT! (not u Fishleg, you know better)

[bush_tech]

Re: C7901 3252ci

Was this ever resolved? I am having the same issue as the original post. Exhausted all of the obvious and less obvious possible solutions. Anything "Outside of the box" I can try to get this machine running?

Extremely late reply, but no we ended up scrapping this machine once Kyocera just told me there's nothing left I can do and they have no idea what it is.
Still irks me to this day even though the machine is long gone

[Peter Adiema Amukoa]

Good precious technicians have Kyocera 3252ci color with error c7901 should I replace the board as I have seen from your post, am planning to buy a new PWB DRUM DLP CONNECT ASSY SP. Please advise

[KYO_OEM]

Have had similar case yesterday.
No counters and serialnumbers at all. No DK, no DV, no belt and no fk unit visible
After i removed ALL LLU parts i reassembled the LLU parts step by step
startet with fk unit only (FK not connected to drum developer relay pwb) and U167 data visible again
connected transfer belt and U167 was gone again.
Disassembled belt again and reassembled dks and dvs step by step.
1 by 1, each time i removed the previous installed parts and checked data.
All counters visible without transfer belt.
Checked transfer belt connection pwb for harness --> NO harness
After assembling from new belt, system works well again.
4h working time....

[blackcat4866]

Nice troubleshooting. =^..^=