HP LJ 4500 - 54.2 Error

[Francog]

where do i begin. new cartridges. vacuumed as best as possible. cleaned sensors, PS10, PS11, PS12 & the one on the Carousel Drive assembly too. using manual, disassembled right side of printer down to the carousel drive assembly BUT did not remove the carousel itself. Could not find a reason why since NOTHING feels or sounds as if there is an obstruction or binding of gears. Carousel turns, with brake disengaged. Not willing to purchase replacement parts just to 'test'. I am NOT a bench technician nor do I have equipment to test with. I realize I am at a disadvantage but would like to figure out WHY I keep getting 54.2 error and how can I pinpoint exactly what mechanism is failing to produce this error? Any assistance would be helpful. After re-assembly, all sounded good... then 54.2 reared its ugly head once again!

[cs_steve]

There is a sensor in that Carousel Drive assembly that can get dirty/damaged/malfunction ... even though nothing "looks or feels" out of place in relation to the Drive Assembly, it is still a likely culprit ... in a case like this, you're left with no option except to "Plug & Play" parts until something fixes it... this error has many possibilities, so without seeing the machine for himself no one will be able to tell you exactly what is causing the 54.2 error is on your machine... however, the error is commonly fixed by replacing the Carousel Drive Assembly ...

[mixmaster]

If I remember right, you can perform a sensor test within the service menu, which you need to hit a certain button on power up (I have not worked on one of these for nearly 5 years!)

That may help you pinpoint which sensor is misbehaving.

IF the carousel has been replaced previously, there may be a plate mounted in the middle of the carousel that looks like copper (or that color). I've seen units where that metal plate has been mangled and causes just enough resistance to throw up the error. You can remove that piece (1 or 2 screws; the plate is used for features of a 4550.)

[MichaelTech]

There are two drives in the rotary drive assy. One turns the carousel, and one turns the toners in the carousel. that is the one that is bad. Remove, and turn the inside gear by hand. You will feel it is rough. Replace.

[DCO57]

Its the Drive assy 80% of the time. I just replaced one, it still showed 54.2, so I had IBM (they support HP now) send me another one. Sure enough, the first one was bad and now it works.
DCO