M1212NF fails to initialize or stuck on initializing loop - scanner glasses cleaning

[_mario_]

Good ability to DIY is a requirement.

This is the second time I run across this problem. The first time the printer resumed its functionality but I don't know why, I only noticed the number of total printed copies goes to zero.

This time the printer resumed its functionality when the scanner reached the right end of the glass (I was looking at it) after moving a bit after each init loop.
I then have been able to complete the PERMANENT STORAGE INIT procedure that was started before, and was still running.

The printer was able to print, if this happens it could be the right moment to try to reload a working firmware.
I didn't do that because I didn't realize that this was the right time.
I must also say that I do not remember to have updated the printer firmware in the past so it's really possible that my problem is different, even if the symptom is identical. Not reloading the firmware has been a good thing.

Unfortunately the next power-on failed to the init loop again.

As I read on the net someone said that he solved his problem cleaning the exposure glass (inside).
Mine was clean but the small glass at the left side, were the scanner move at the beginning, was internally opaque.

I decided to start the scanner disassembly, anyway the printer with this failure is unusable.
Moreover opening the covers allows to disconnect and reconnect the cables to clean false contact (in electronics there are always false/intermittent contact during the product life due to material oxidation. Not with gold).

Good ability to DIY is a requirement.

Before starting, the m1212nf (m1130/m1210) Service Manual (not User) needs to be found, it's on the net.

Page 22 shows how to remove the left cover. Once removed the scanner connection are visible.

BE CAREFUL, WITH THE COVER REMOVED YOU HAVE NO PROTECTION AGAINST ELECTRICAL SHOCK IF YOU PUT YOUR FINGERS IN THE WRONG PLACE OR YOU DO NOT FOLLOW CAREFULLY THE SAFETY ELECTRICAL RULES.
DON'T DO ANYTHING IF YOU ARE NOT A TRAINED INDIVIDUAL.

I disconnected the scanner black flat cable and the small two wire cable that are located in the upper left corner.
The printer now shows the scanner error 13 on LCD after powering it on, but it's not stuck on the init loop.

At least it could be used as a printer!

This is probably again a good time to try to reload the firmware if you need it.

At this point the Service Manual shows how to remove the scanner assembly from the unit, I had some difficulty with the item in fig 1-44, page 31.

PAY attention not to damage the cables once they are free, use some piece of tape to fix them to the scanner body.

The Service Manual then ask the ADF to be removed from the scanner. I didn't do that and have had no particular problems.

Opening the scanner box require removing six screws on the top side and two on the rear side, then it opens like a book.
Some (2) special thin tools may be required to unscrew some screws.

Keep the scanner box horizontal and open the glass like a book, some small parts may stay attached to one side while other parts will be on the other one, they should be moved to the horizontal base before reassembling.

Now the scanner electronics and the cables are exposed and can be disconnected and reconnected to clean the electrical contacts oxidation.
It's also time now to clean the inside part of the two glasses. Pay attention not to leave dust or any cleaner halo.

Reverse all operations to reassembly what you have disassembled till now.

My m1212nf do not loop anymore and works well now.

Mario

p.s. English, not my language 😉 Corrections are welcome.