HP 6950 reports carriage jam, but carriage moves freely

[Bob1249]

Hi, I have a 6950 inkjet printer that reports a carriage jam, even though there is nothing blocking it. I have attached a video that shows the startup sequence of the printer. The carriage seems to get pulled back for a moment and then gets unstuck and can move freely again. What is the cause of this error?

[Valsimot]

Above the carriage rod there is a thin plastic calibration strip, clean it with cloth damped ih hot water. Use 2 fingers cloth and the strip between 2 fingers clean it from left to right. Maybe it will help. When cleaning do not use pulling force that might break the calibration strip.

[Bob1249]

Thanks for the suggestion, however I have tried to clean it and the issue persists. There is a stain on the strip that I can't get rid of. Could this be the issue?

[Valsimot]

If the stain is on the right side might be, on the video it looks like when the carriage is on the right it bangs strangely then goes to left. Also, check the carriage rod if it is dry 2-3 drops of oil will help the carriage to move more freely.

[Bob1249]

The stain is indeed on the right side. Adding grease to the rod did not help. I have ordered a new encoder strip from ebay (Part No. B6P40-80004), which will arrive in September. I will report back if that fixes the problem when I get it.

[Valsimot]

Use cloth + mild detergent and hot water to clean it. 

[Bob1249 · Accepted solution]

I bought a replacement encoder strip, and now the printer works again. Thank you for your help

[magpie69]

Hello Bob, can you advise about replacing the encoder strip? My printer is having the same issue and I'm unsure if it's something I can replace myself. Thanks.

[Bob1249]

Hi, it is fairly easy to replace the encoder strip. I'd recommend trying to clean it first if you haven't already. The strip is connected to two metal hooks on the ends that you can push inwards to remove it. The strip is also routed through a little sensor on the carriage. Make sure to make a picture of the markings on the left or right of the strip to know the orientation of the strip when you install the new one.