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Zesti
11-27-2017, 08:10 AM
Looking for attention of senior Bizhub techs.
Have that older and my favorite C652. It started creating digital noise like sequential lines and boxes on copies, prints and internal test prints. Tried all the adjustments first and all the internal tests like RAM were OK. The problem grew up over time and last print is attached.
I tried replacing available PH unit and drive board with no good effect. I suspected the MFP board part no. A0P0-H021 found one, received, installed but no display. The engine initializes but panel is blank, no keys responding. I tried flash the machine and it seems that the USB was detected by machine on service port as engine does not initialize but no display whatsoever.
I noticed some difference of writing on boards regarding part nos. Images attached for new and old board. Kindly shed some light on what could be wrong.382623826338265ng.

srvctec
11-27-2017, 09:37 PM
Is the new MFP board actually new or from another machine? If the machine's display was working before the MFP board swap, then the "new" MFP board is bad or a connector isn't seated properly somewhere. Have you tried to put the original board back in to make sure the panel still works with it? Also, for the initial problem, swap out the memory board(s) to see if anything changes. I had something similar happen on a C552 and it turned out to be the MFP board.

EarthKmTech
11-27-2017, 10:58 PM
you could try getting someone handy with a hot air soldering station to replace the soldered down ram chips on the working but image defecting mfp board. Its not actually that hard. I've long expected this to be the problem but have not tried personally as we just change whole boards.

I just threw out a 1 foot pile of good used mfp boards for this series and others similar we don't service them anymore.

Zesti
11-28-2017, 05:53 AM
Thanks Srvctec and Earthkmtech,
The board I got was new as mentioned by seller. The seller said he only sell boxes no technical know how:confused:...
The old board is still working with faulty image.
Unfortunately I don't have another C652 to cross check the fault.

I'm inline with advice from earthkmtech, the old board is already with me and I have to visit an electronic board geek to do the same.

Any advise regarding marking of boards I posted.

EarthKmTech
11-28-2017, 06:47 AM
both boards are a0p0h021 mfp boards it must be defective. did you remember to plug in the control panel in and are there led's lit up on the board (indicating it is powered)?

Zesti
11-28-2017, 10:16 AM
both boards are a0p0h021 mfp boards it must be defective. did you remember to plug in the control panel in and are there led's lit up on the board (indicating it is powered)?Yup the panel connector is well checked. Good point about LED's on of board. The non working board has few LEDs not glowing while these glow on old board. Any info about LEDs on mfp board, couldn't find in sm.

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