Repairing an HP Photosmart B9180 printer

The following text was posted to an HP B9180 user group @ yahoo. Unfortunately I didn’t manage to take photos of the inside of the printer.

My 4y old B9180 started making horrible noises. The noise originated from/near with the motor responsible for switching between the hard- (capping) and soft (spitting) sponges. I took it apart (documenting what I did) but didn’t reach the actual motor as it is hard to reach. I ending up buying a new printer last week.

I found some friends willing to take another shot at repairing the HP B9180, and together we spent another afternoon taking it apart again. This time we got further. We reached roughly the point that ralphfcooke reached (sounds like climbing Mt. Everest).

Conclusions and questions

1. Broken gear.
One of the white plastic gears below the waste tank was damaged. One or two teeth were missing. This explains the gnashing noise. Any suggestions how to fix this??
The gear is about the shape of two coins with slightly different diameter pasted together. Both “coins” (quarter/Euro sized) are gears with somewhat different diameter.

Interim answer: considered taking the Shapeways route (creating a custom gear via 3D printer), but Ralph offered to sell a handful of parts. The should arrive soon.

2. Root cause?
The gear probably failed because something in the drive chain between motor and the rack-and-pinion to move the hard/soft sponge assembly was jammed. Is this credible? We didn’t find the actual jam, but there was ink all over the place – including around the gears. What are the chances of the gears breaking again – now that we cleaned up all ink around the moving parts? Could there be a sensor (that we don’t know about) that failed?

Interim answer: hopefully the jam was caused by ink. There seems to be a sensor (coding disc) at the other end of the motor axle. But it is unlikely that this failed?

3. Discovered a mini vacuum pump
The 4 hard sponges are attached (via 2 silicone tubes and T-junction) to a small pump. This pump causes the loud clickety-click noises heard on healthy machines during capping. The pump is a peristaltic pump that literally pushes out air by squeezing soft silicone tubes. A bit of under-pressure is apparently intended to improve the effectiveness of the soft seal ring around the 4 sponges in the capping station. It serves the same purpose as the cap on a pen: it reduces the chance of the print heads drying out. The vacuum-assist pulls the caps and the heads tighter together (think “suction cups”). Do other printers also do this?

4. Discovered a larger tank for dumping ink
Likely already known to those who have taken their printer apart far enough: the 4 soft sponges can dump their ink downward into a large tank filled with felt. This is probably done when the heads are “capped” as it must take a long time for partially dried ink to trickle down. We removed the felt instead of washing it as the felt is probably only important when you ship/store the printer upside down.

5. Test plans
Once/if the damaged gear is fixed, it might be good to do a (literal) dry run: test if the mechanics sounds ok before allowing the print heads to discharge ink. Reason: if the mechanics fail, the print heads will be discharging ink all over the place. In fact, I have literally seen small puffs of ink mist (being mist consisting of ink droplets!) emerge from the open printer. Probably best not to inhale these – although resin-encapsulated pigments don’t sound too toxic. To do a dry run we are considering re-assembly with the flex-foil (wiring to the print head) disconnected. Any thoughts?

6. Waste tank design?!?
Just out of curiosity: what was HP thinking when they created a hardly serviceable waste tank deeply embedded inside the device. When is this serviced and by whom?

Interim answer: say you can dump 200 ml in the tank (half evaporates?). If 90% of the ink gets onto paper, and 10% of the ink is needed for maintenance (sneezing, coughing to clear the print heads), it should last about 75 ink cartridges (@ 27 ml each). So arguably the ink tank lasts the economic life of the printer.

Acknowledgements

Again my thanks to Ralf Cooke’s recipe on taking the printer apart. We seem to have a slightly different problem ( no “sheared gear axis”) but the problem is pretty close.

8 thoughts on “Repairing an HP Photosmart B9180 printer

  1. ralph cooke

    I have stripped down a couple of b9180 printers for spares. If it’s any help contact me by email for spare parts.

    Reply
    1. Dai Brogden

      I have recently cleaned the NEDD on my B9180 but in the process I damaged the ribbon cable connector that plugs into the PCB on the right-hand bulkhead. The printer thinks everything is OK but won’t print cyan – it just comes out grey. Do you by any chance have a complete ribbon cable ?

      Reply
    2. Eric Buckley, Jr.

      I received one used. Damage in transit caused printheads to jar out of place disconnecting them from the drive belt. How can I reassemble? Eric

      Reply
  2. Kevin Lee

    Your post was very helpful. My b9180 repeatedly hung up on “service stall”. I thought it was a software error because it was sudden and happened after I tried to cancel a print job. But I couldn’t fix it via software, or tricking the printer to print – so with little to lose I began taking it apart. Your article and Ralph Cooke’s gave me the confidence to do this. In one day I stripped it down to the gears, springs, and silicone tubes, washed out all the ink that had build up over three or four years of light use, and miraculously (for me) reassembled it – correctly. And it’s fixed! I think the problem was excessive ink around the mechanism that allows the caps to reset over the nozzles. I noticed during disassembly that the piece with the caps on it wasn’t landing anywhere in particular, and was at a slight angle to the housing. After the cleaning I was able to see how it was supposed to sit — and now that’s what it does.

    The only problem (besides an occasional, frustrating misfeed) is that now I have printer lust for the Epson 3880.

    Thanks for the inspiration.

    Reply
  3. Jason Davidson

    Peter

    Just to ask whether replacing the gear actually worked? I have exactly the same problem with my B9180 and am considering a 3D printing service. I thought I would ask if you got it fixed and there were no further problems or whether you didn’t bother at all!

    Yours

    Jason

    Reply
    1. pvdhamer Post author

      The printer is at my niece. We traced the problem to the gear. Then I bought a handful (to be on the safe side) of spare parts from Ralph Cooke. The parts arrived, but I don’t know whether they were actually installed. I will inquire.

      Reply
  4. Jerry Fraser

    My B9180 has started to loose its grip at the end of an A3 print causing the last two cm. or so be all over the place.
    I have had it five years now but not yet needed to look inside. Are the clamping rollers, or what ever dificult to get at and adjust?
    I had the same trouble a couple of years ago on the special media tray but chickened out and stopped using it but this of course is more serious.
    thanks
    Jerry

    Reply
    1. pvdhamer Post author

      I remember vaguely that you can clean the rubber rollers with q-tips dipped in pure alcohol. I don’t own the HP anymore (a gear failed).

      Reply

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