The easiest way would be to go to www.janome.com, click products, sergers, then mylock634D (644D is also mentioned). Along the top, chose 'photos/video'.
If you would prefer to have the cassette, simply contact Janome Customer Service and they will send you a replacement ($$)
My mum had the same issues after a cataract operation. She bought magnifying spectacles, that clip onto your normal specs (A lot of hobby shops sell them). I've added a link to a page that shows some, but you can just Google "Magnifying Spectacles" and have a look at the results (You can pay anything from about £10 to £300, depending on the style and purpose (The link here takes you to some priced at about £15). THIS IS NOT A RECOMMENDATION FOR THE PRODUCT THE LINK RELATES TO, it is just a random example taken from a Google search.
Overlockers/sergers are completely different to a sewing machine and taking a class on your model is invaluable in the initial learning curve of threading up, adjusting tensions and doing different techniques, something so much easier to watch and learn rather than reading the manual.
I have this serger, also. A friend (who knows sergers) and I spent 2 hours today trying to get the lower looper threaded--with no success! There is a diagram in the door of my machine, but it is still very confusing! I'm taking mine to the shop on Monday and have them thread it and show me how to do it!
Are the cloth plate and front looper covers fully closed? some machines have safety cutout on these for obvious reasons.
Check this firstly.
Can you hear the engine humming?
If yes, but no movement when you press the foot pedal, then it is possible that a gear inside the main drive area has failed. Try manually turning the flywheel towards you, if there is no movement from the loopers and needles then this is likely.
I have a toyota over locker and it has being threaded it properly but it does not want to loop, could you please help me? please email me back on [email protected]. thank you Maria