MX-4101N - black display

[Toner Boy]

Ruled out MFP controller and RAM, scanner controller, PCU. Going for the DC power supply next unless someone has a new direction to point towards...
Machine sits with controller box fan running, power indicator lights on all boards and on front panel on/off switch. Have seen a couple milliseconds of flicker in the black/color copy buttons and can hear the HDD clicking briefly when power switch turns on. 125K on engine. Pulled fuser, finisher, doc feeder peripherals- no change.

[igi]

Re: MX-4101N - black display

hi
did the customer adjusted display density too dark?
scanner control pwb,

[bilyahn]

Re: MX-4101N - black display

We have had the connector to the LCD display on the op panel cause this. Took the op panel apart and reseated the connector and started working again. Also might want to check out the LCD converter PWB CPWBF1829FC31
There's a TT-20120 about this causing blank displays.

Good luck.

Bil

[Akitu]

Re: MX-4101N - black display

Some of the other techs in my company have reported that the USB converter PWB was the cause of their screen issues, problems ranged from flickering, to unresponsiveness and even a totally black screen.

CPWBN1817FCE1

[Toner Boy]

Re: MX-4101N - black display

There is no boot up. No engine rotation, no fuser warmup etc. But I'm gonna grab a display off another machine to bring with, will update. Thanks for suggestions.

[Akitu]

Re: MX-4101N - black display

There is no boot up. No engine rotation, no fuser warmup etc. But I'm gonna grab a display off another machine to bring with, will update. Thanks for suggestions.

Do the fans fire up at least? I had a faulty boot ROM in an MXM363 that displayed similar symptoms, only the fans would fire up.

[Gadget29]

Re: MX-4101N - black display

I had one do the same thing and it was DC power board, try testing voltages

[Toner Boy]

Re: MX-4101N - black display

It was the DC power supply, all fuses are good. I've never had an MX-series DCPS go bad but this one is hopscotched on extension cords due to distance from wall outlets probably not getting enough power; which we will try to remedy. A strange symptom (probably from all the board and chip swapping) was that when it would try and print a counter page or 22-6 paper would start to feed and machine would immediately reboot, but after testing all trays with copy and a couple reboots everything seems to have sorted itself out...I hope.

[Toner Boy]

Re: MX-4101N - black display

Well, not too happy 'cause it burned out the second DCPS within 6 hours or so. Had to pull machine and put in a replacement, hard to diagnose any motor or other board causing the issue since I've got no power again. Now we've got 2 useless machines in our shop, 1 we can fix w/ new DCPS, the other may become a parts machine at this point. The Scanner control PWB, MFC controller and PCU boards (from the trouble machine) all worked in our shop machine, granted we did not leave it on for a long time.

P.S: If anyone knows why the fuser units on these models wrinkle paper (even letter size) within 100K I sure would like to know. There are no Sharp updates or part changes other than the upper fuser bushings that I know of, and it does it with those as well. You can change FSM (fuser speed) to compensate a bit and get a bit more life out of them but there has got to be a better way.

[Gadget29]

Re: MX-4101N - black display

Sucks to hear about the dc controller... I'm not certain about this but wasn't there some problem with clutch wires coming out of the wire holder and shorting out on the metal housings, when I get to the shop in the a.m. I will look...But the fuser issue, we actually applied extra material to the bushings to make the fit of the bearing tighter... Seems to be working so far...

[mojorolla]

Re: MX-4101N - black display

Plug the two blown boards into a bench power supply and find which harnesses are fried. The blown harness will point to the short.

For the fuser, remove and clean the entrance plate. This model will form clumps on the ridges of the baffle and cause wrinkling. Also, remove the useless "cleaner bar". All it does is collect rock hard leftovers and damage the roller. I take these off in 2600 and 3100 too.

[Toner Boy]

Re: MX-4101N - black display

Check this out. Since the machine had rebooted after it began feeding a test page from tray1 after replacing the DCPS the first time, and from Gadget29's clutch mentioning I decided to check out the PF drive unit, the top clutch felt rough when I turned it (CPUC1). Removed clutch for inspection and this is what I found...PCLC-0373FCZ1.jpg I'd be willing to bet the DCPS has lost its 24v output, 99% sure this is the cause of our misery. Housing has been grinding away at the wire for a while now it seems. Power comes from PCU board, hopefully it is still functional since it was when we tried the PCU board in our shop machine and it worked.

[Gadget29]

Glad to hear you found it, just wish I would have thought about it sooner!!!

[bilyahn]

Re: MX-4101N - black display

That's an awesome piece of troubleshooting! Great job and thanks for the heads up!

Bil