12-19-2017 10:31 AM
For all guys missing support for their devices regarding this error here a few facts
The error is caused by a micro switch that is pushed by the white lever while closing the door.
If that piece is broken switch can not work and there fore you get the error message.
Like it or not but you are a lucky one cause you only have to fix that tiny piece by glueing or by replacing it and buying it as a used part cause now I have a few of them after I had to repair.
If your piece is looking like this things become more serious cause then most likely your micro switch is dead.
You wanna know if that is dead?
Well, that is pretty easy to check if you have understood how it works.
The rear door and its white lever is driven by a spring that let the lever press upwards.
So the micro switch must be above that point where the white lever goes into the device corpus.
Here is the picture where you can see a screwdriver starting to do the job the lever normally does.
But the screwdriver allows me to show how it works.
You have to push the micro switch a bit more upwards and then the error message will disappear assuming the door is closed.
If you are not able to work from down below the printer and in parallel checking the display there is another trick.
If you push the switch upwards you can not see or hear that it works but if you let it down again you will hear a sound of a relais and that will appear as a signal that rear door is open (again). Press the microswitch upwards and then let the switch fall down again to hear a tiny but hearable sound of a relais.
Well, at least now you can understand what is causing the problem but to solve it that is another side of the coin I have not identified yet.
But you should ask your local dealer and HP why
* they do not deliver these documentations ?
* HP uses a microswitch that breaks after 10 times of usage cause our printer have below 5000 printed pages , no jams, therefore no need to open this door ?
* HP quality control did not stop this faulty switch desaster by a new supplier / different switch ?
A micracle that HP does not explain a solution or offers these parts as far as I had checked the reference and part list. The only thing I found out is that the micro sensor or switch regarding rear door open error is called SR607 and that this SR607 is connected to the high voltage Power supply. But no part number.
How to fix that problem?
I still do not know if there is a switch I can exchange and how.
But I fear that I have to remove all body covers to get access to that area and to exchange that piece.
No, I do not know where to buy these parts and if the switch is dead or something is broken inside but I assume that your local HP dealer won`t be able to sell you the parts you need to get it fixed.
The only chance might be to buy dead M276 that died by another cause than the rear door is open error.
I will try to fix it cause I had bough dead machines as spare part donators in the hope to fix the problem.
And this is a very expensive repair cause the machines are heavy, shipping is quite expensive so I had to pay over 75$ for the complete dead machine - instead of buying a spare part from HP for 5 or 10€ including shipping.
What a shame and desaster regarding to call themselves a sustainable company while kicking the devices in to the trash can by simply not offering parts and support which could be delivered easily ...
If HP does not change that I will be gone - after 30+ years of HP printer purchases.
12-19-2017 12:52 PM
Forget about micro switches. That is a myth.
I was able to remove the complete plastic structure and VOILA there is no micro switch.
Instead there is a lever and there are a LED and a photocell that detects the light beam - or no light beam.
As in life darkness means trouble, so if the photocell does not receive light you will get the rear door open error message.
The light beam is controlled by the plastic structure which has a lever that can cover the photo cell or not.
If the cell is covered the rear door is open and you get the error message.
If the cell is not covered the light beam will be received by the photocell and the display has no error message, cause rear door is closed.
Here you can see now the comparison of the lever positions.
On the left half of the picture you can see the lever on the right in up position when the rear door is open.
On the right half you see the lever in down position when the door is closed
The red screwdriver is only to hold the piece in position to take the photo.
The white lever of the rear door controls the position of that black lever you see here by pushing the black lever on the other, the inner side up by the white lever when door is closed as you can see on the right half
The white lever goes into this black piece in the middle and pushes the black lever inside the unit up and therefore outside the black plastic unit down to let the photo cell receive the light beam.
And now you will look onto the right side of the printer from the back onto the position of the black plastic part.
You can see the emitting LED on the right of the PS502 component and the Photocell on the opposite.
And now the cause for all the trouble:
If the led on the right is not creating a light beam the photo cell will not receive any light and therefore it is dark, as dark as the photocell is when covered by the black lever when the rear door is open.
No light, no printing possible cause door is open - for the system.
But: if the light emitting LED is dead then the photo cell will always detect that it is dark regardless if the black lever is up or down.
You may wanna check if I am right?
Easy: take a torch and light onto the photocell.
Suddenly the error message will disappear and display is ready for printing - but the printer is of cause not ready because rear door is open to light onto the photo cell.
Replace the PS502 unit or at least the LED but that seems to be part of the motherboard on that side.
Try to implement a light like an LED with cable and separate switch you can control manually.
But that will be much work to find the power, a position for a manual switch ...
So you can hope to replace the PS502 element and solder that out and solder a new one.
Or you have to find a new motherboard to exchange them. Regardless your way it will be a lot of work.
12-19-2017 12:56 PM - edited 12-19-2017 10:33 PM
I will try to fix that by exchanging the complete board and see if that work and later I hope to try to desolder that photocell and to replace that with a new one.
Depends on how and where to find this photocell part or light break as we call it.
02-13-2019 01:23 PM
I found that when the door is closed the white latch swings a shutter into interrupt the sensor on the hvpsa.
i have this problem door open error. I would like to de solder and resolder a new sensor but what if the logic
is bad. I like that a new sensor fixed his problem though.
So I will weigh the options. Thank you to all who assisted on this resolution. Much appreciated.
Very cool, sensor part#s !!!! Wow
The optical switch is a ROHM RPI-579N1 and the RS part number is 700-3996.
Replacing it fixed the "Rear door open" and paper jam on my M276.
01-15-2020 02:02 PM
Thank you so much for this, you just helped me prevent tossing a color laser printer into the landfill from your detailed investigation and information. I was able to buy the ps502 from an ebay vendor in the UK, it arrived within a week and now its printing again. I should add since no one did in this thread that you have to pry the side panel off, the HP repair manual shows how to do this but if that becomes unavailable for any reason, there is one screw to remove at the bottom of the left panel on the power plug side, the rest you'll need to slowly work off with a pry tool. Once removed it exposes the logic board which has several securing screws. I was able to remove these along with a daughterboard near the front of the unit and swing it upwards--there are 5-6 plastic clips that can be nudged off the board to allow it to swing up. Be very careful near the top of the board as those were not forgiving and there are a few wires that are soldered into the board there so don't try to remove the board at all. I rested the board on a prop and that allowed me to hang a weight on the sensor and all it took was mixing a little dab of new solder on to each of the four joints to easily remove it. I cleaned the holes with a wick and alcohol and the new one fit well to be soldered in, the printer turned on without issue and started printing for the first time in weeks. Thanks again WOLF_PACK!