Tutorial to access fuser

[painter_]

The printer is plugged directly into a wall socket, and has been since day 1.  Might you have any idea what the issue is? At this point I don't think it is the fuser itself, but possibly the power supply, or other related hardware. That said, I'll contact the vendor to see if a refund is possible.  When I originally contacted HP all they said was my printer was out of warranty, and offered no other suggestions for repair.

That info re: the ceramic heater is helpful. 

[davidzuts]

I doubt the power supply is the issue but rather an issue with the dc controller since the fuser connections are plugged into the controller which controls how the fuser works and reports the fuser actions to the formatter. It could also be a wiring or contact issue since most times the 50.2 error indicates the fuser is not getting warm enough and the 50.4 error relates to a wiring issue. All that said the controller does not cost that much and should be fairly easy to install. In fact since you have the manual I would remove the right and upper covers and just disconnect all connections to the current dc controller and then reconnect them to see if there is a difference.

https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2322090.m570.l1313.TR0.TRC0.H0.TRS0&_nkw=Rm1-8704...

[painter_]

Thank you! I'll try that, and update this thread. Once you've done it, removing covers is not a very daunting task.

I really appreciate the suggestion, and the link to the part! For the $12, I'll probably pick one up. Right now I have a lump of plastic that's only useful as a scanner.

Thanks again.

[Copier-Pro]

I will try and help.Inside the fuser unit there is the thermostat and thermistor,These are very sensitive parts for controlling the lamps and the heat.I did find that a toner build up on these parts can give the wrong readings to the machine.Clean these parts and retry the machine.A refurbished fuser does not mean that they changed these parts.Hope this will help.

[painter_]

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@Copier-Pro wrote:

I will try and help.Inside the fuser unit there is the thermostat and thermistor,These are very sensitive parts for controlling the lamps and the heat.I did find that a toner build up on these parts can give the wrong readings to the machine.Clean these parts and retry the machine.A refurbished fuser does not mean that they changed these parts.Hope this will help.

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I installed a brand new OEM fuser, not a refurbished unit. It had never seen toner.

[Copier-Pro]

Maybe someone can help out here with a permanent initializing.That is about whats left to check before changing boards.

[painter_]

By permanent initializing, do you mean a cold reset?

[Copier-Pro]

As far as i know there are 2 resets cold reset and like a full reset.Try to get the full reset on this machine.Hope this is going to work.Maybe a firmware upgrade might also make a difference.

[painter_]

Maybe one of the HP folks can give me instructions.

[davidzuts]

Lets make this real simple.Cold resets and NVRAM resets when possible will not solve a 50 error since this error is generated when the printer tests or attemps to heat the fuser. Also keep in mind the technology of fusers has changed over the years from using heating lamps to now using ceramic heaters which are more stable and not effected by toner build up. Since replacing the fuser with a brand new one does not solve the issue it would appear the fuser is not the problem but rather other components and the first suspect would be the dc controller. It still could be a power supply or wire harness issue but the dc controller is cheap, easy to get to and would be the first thing I would try after reseating all connections on the current dc controller.