It sounds like you have a Wheelwriter 15 Series II based on the model number you gave, but the answer is probably the same for almost any Wheelwriter: There is a small mechanism, I believe called a solenoid, that moves a horseshoe-shaped part that actually "fires" the striking hammer against the individual letter-spokes of the daisywheel print element, to put letters/numbers/symbols on paper. I have posted a close up photo of the left hand side of the carriage that moves back and forth while you type, which holds the ribbon, correction tape, and mechanisms for positioning the daisy wheel print element so that the hammer can strike the correct letter, number, etc. when selected from the keyboard. If you go to your machine and remove the ribbon and correction tape from the carriage, you will see that right in the middle of the picture is the thing I'm talking about. It looks like a small electric motor like you might find in a toy racecar, is about the same diameter as a USA "quarter", and is I think about an inch thick. I've replaced one of those once, using the part from a damaged typewriter to replace the matching part in a typewriter that worked except it wouldn't print, just like the problem you describe. It's been a few years since I did that but it did not require any specialized tools, and I did not have a manual or a video to refer to. I think this mechanism has stayed mostly the same for about 20 years worth of Wheelwriters, though I can't promise that a part from a Wheelwriter 3, for example, would work to replace the seemingly same part in a Wheelwriter 15 Series II like yours. I think there are many places you can buy this part from online, and with the information I've provided here they may better be able to help you trouble shoot your problem. I can't promise that this will fix your problem but there's a pretty good chance that it will. As far as what I do is concerned, I buy, fix where I can, and resell Wheelwriters, mostly on ebay, and some time in the next month or so I'll start selling Wheelwriter parts. I bought a pallet of 20 Wheelwriters a few months ago and it turned out that many of them were damaged from how they were stacked on the pallet (which I kind of expected even though I couldn't look through them all ahead of time). I've sold the undamaged ones and parted together a few more to sell, but soon I'll run out of enough undamaged cases to sell complete units and that's when the parts sale begins. I don't think you'd want to wait until I get around to selling parts, but if you do want to check out what I've listed, I'm on ebay as "greatsurplusbuys". -- Dan