ImageWriter II ghosting

[theonetruetom]

I've been working on an ImageWriter II, and I'm having some issues with print quality that are making me scratch my head. It's acting as if the platten isn't entirely round anymore, but only in some spots:



Anybody seen this before? Ideas?

 

[theonetruetom]

To add to this, this is a new ribbon, normal weight paper (sheet feed for the moment, though I have some pin-feed paper ready for when this can print a page properly).

 

[RepairManiac]

Yes. I have seen it but its been decades since I repaired dot matrix printers on the regular.

No on the platen. If there is an issue with it, you can visibly see damage.
If it was light on one side, then the platen needs to be adjusted or shimmed.

I'd check for the following:
* You say new ribbon, but is it tight (can you wind by hand normally outside of the printer?)
* Manually move the carriage assembly back & forth, does the ribbon continually wind?
* Inspect Ribbon winding mechanism. Look at the motor and gears. Can't remember if it had a wire or string, if so is it loose - should be tight.
* Occasionally I'd see a stuck pin on the printhead. Inspect the ribbon, does it have holes in it? Soak the front of the pins in alcohol
* Inspect the paper guide - Is the hole normal shape or all messed up? If so, Replace the paper guide or file down the snag.

 

[theonetruetom]

Ribbon is new and winds properly as the head moves across. I already took the printhead off, cleaned it with some isopropyl, and I'm not seeing any symptoms of a stuck pin (I'd expect a horizontal line of blank space, rather than vertical ghosting).

The paper guide-- If you mean the clear plastic piece around the head that keeps the paper going the right direction, that part's fine.

I did take the time to move the carrier adjustment a bit using the screw on the end, and print quality improved towards that end, but it doesn't seem like the left end has any adjustment. It seems like the carrier bar might actually be slightly bent, at this point. Is it possible to replace the bar by itself, or is this a "replace the assembly" thing?

Addendum: I added a sheet of paper and tested print again. I still have a darker line where one is in the picture, but the left side is much more readable. Seems like I might need a shim, or to improvise a shim, if none are available. Anybody got a source on the original part?

 

[ymk]

Have you adjusted the paper thickness lever? It's the short black lever on the right end of the linear slide.