MP 5500 with dead web motor

**Shadow1** · 11-11-2013, 07:40 PM

Re: MP 5500 with dead web motor

I've had many times more web motors go bad than boards - just because the motor worked in another machine doesn't mean that it's good. Those motors are infamous for developing "dead spots" and it only takes a small bump to turn it away from the dead area. Given the cost of that motor I would highly recommend replacing it just to make sure there's not some sort of defect that took out the board.

Having said that, I have had to replace a few boards - it takes special equipment to properly repair surface mount boards, so we don't bother and just ship them off to Hytec or some such repair service.

Only one of the boards failed with no explanation - the rest were a result of a shorted harness. The leads from the motor can easily become pinched when the front cover is tightened back down on the fuser/exit drawer. I always reroute the wires from the motor on the inside of the motor/gear/drag assembly to make sure that can't happen.

**Herostrat** · 11-11-2013, 07:50 PM

Re: MP 5500 with dead web motor

I tryed another motor from working web assy,and he didn't work on faulty machine/board.
Perhaps I overlooked some flaw in harnes,but thanks for advice.

**Shadow1** · 11-11-2013, 08:41 PM

Re: MP 5500 with dead web motor

It's the harness attached to the web motor itself that gets pinched. You probably would have seen it when you pulled the motor out. Not saying there's not a pinch somewhere else, but on the motor is where I ususally see it.

**Llama God** · 11-11-2013, 10:49 PM

Re: MP 5500 with dead web motor

Originally posted by Shadow1

It's the harness attached to the web motor itself that gets pinched. You probably would have seen it when you pulled the motor out. Not saying there's not a pinch somewhere else, but on the motor is where I ususally see it.

I've seen these pinched before, usually by the front fuser cover. I've not had a motor take a board out on these, but I have replaced plenty of motors.

**slimslob** · 11-12-2013, 12:19 AM

Re: MP 5500 with dead web motor

Originally posted by Shadow1

It's the harness attached to the web motor itself that gets pinched. You probably would have seen it when you pulled the motor out. Not saying there's not a pinch somewhere else, but on the motor is where I ususally see it.

I have also had trouble with that harness. I have not had one take out a board, yet. I have had them rub against the screw head that is near it and short out the signal from the web sensor. Replaced the web and a couple of days later, got a SC 550, web end. Went back out. Noticed the harness. Repositioned the harness and no more codes.

**Tonerbomb** · 11-12-2013, 12:53 AM

Re: MP 5500 with dead web motor

All valid points regarding the pinched wires, never had anything web related take out the BCU though. The 1 thing I didn't see listed is that little tiny motor is weak and gets toasted by the heat, and it just plain fails !!!

**Codex** · 11-12-2013, 01:54 PM

Re: MP 5500 with dead web motor

i made a kind of "Web Motor Tester" by myself.....some batteries and the right connector, just to see without any sp if the motor works.....i use it very often

**Herostrat** · 11-12-2013, 05:50 PM

Re: MP 5500 with dead web motor

I looked in to one machine that has dead web engine today,and harnes is perfect.
I went further to inspect entire fuser wiring and at the back leading to BCU board,everything is in order,even web assy gears are tip top.
I'll give it a shoot with changing Toshiba chip and post update.

**Drummer** · 11-12-2013, 09:16 PM

Re: MP 5500 with dead web motor

You may want to check the orange foam roller in the web assy.
Most of the time when I had a web motor go bad or break the gears in the web assy. the orange roller was to blame.
They develop flat spots on them just big enough so that when it stops in the right position ( flat spot against the heat roller ) the web motor doesnt have enough ummmph to get past it and ends up killing the motor.
It is when the motor is dead or the flat spot holds it up, that the web does not move anymore causing the web to build up with toner, in turn the web starts (bouncing or jerking) against the heat roller and that is what usually breaks the gears.

**Shadow1** · 11-12-2013, 11:27 PM

Re: MP 5500 with dead web motor

I've never had all that much problem with the web drive gears breaking, but when I do it's usually just from long exposure to heat. The hot roller drive gear on that series is another story, and that's just inappropriate use of a plastic gear combined with a pressure roller extremely prone to flat spots (even with the pressure release assembly)

**Herostrat** · 11-30-2013, 07:17 PM

Re: MP 5500 with dead web motor

I was inspecting the faulty board today on service.
I mounted it on one machine and I opened another machine for comparing.
Used osciloscope to measure voltages on pins at and around the toshiba chip,allso I measured the wires connecting bcu and web motor with a help of Point to point scheme.
The working BCU board gave me a clear picture what pins give those 5 volts and once I measured the broken one I found out that it's not Toshiba chip to blame but a little SMD element that I can't even read the marking,looks like Triac or Thyristor.
This means that I can't fix the board it self,don't have the tools to unsolder SMD electronics,I'll swap BCU board.
I'm still not shure what owerloaded that element,we have machines on maintenance with far worse web asselmblys than this one,in terrible condition and yet those work fine with BCU boards intact.
Unfortunately I don't have access to sevice bulitens about the matter (if there is any) to get more info,instead of this "reinventing of the hot water"

**Shadow1** · 12-02-2013, 02:10 AM

Re: MP 5500 with dead web motor

Originally posted by Herostrat

I found out that it's not Toshiba chip to blame but a little SMD element that I can't even read the marking,looks like Triac or Thyristor.

Both of which are A/C components. More likely just a transistor - If you're that hard up to be doing your own component level reparis you could probably clip it out and hotwire a 2N2222 or 2N3904 (PNP vs. NPN) in its place if you're careful to figure out the EBC connections.

**Herostrat** · 12-02-2013, 08:10 PM

Re: MP 5500 with dead web motor

I talked with some tech's and they all agreed that board shuld be replaced and one told me that repairing on component level destroys the board,he showed me the board he took to electronics workshop...it was 2 transistors in his case and BCU board blew up after replacement.
I have some basic knowledge in electronics and 2 BCU boards I can play with,I actualy have those transistors at home...I'll give it a shot just to try it,no harm will be done even if those blow up because boards are already replaced on machines.
Thanks for replies guys.

**Shadow1** · 12-02-2013, 09:19 PM

Re: MP 5500 with dead web motor

Without being able to read the numbers off of it, there's no way to tell if it's a PNP or NPN transistor - and it could be a FET or darlington pair, or some other crazy component - If you can read one of the other ones I'm betting it's the same as all the other similar components on the board, if they're using small switching transistors then why would they use a bunch of different ones unless some circuits had higher current requirements. The 2222 and 3904 are the most common switching transistors in use and they're pretty cheap, so if it blows smoke you haven't lost much

MP 5500 with dead web motor

MP 5500 with dead web motor

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