mine is a Viking MegaQuilter 18x8 - which is essentially a rebranded Tin Lizzie.
First thing to check is make sure all your cables are snug - nothing loose or wobbly. And sort of the same, check the "pins" in your connector cables, and make sure none of them are bent.
When you push the "needle up", does it go all the way down and back up? If it does what it's supposed to, and the "needle down" doesn't do ANYTHING, you've definitely got a bad place under that button... and you will probably have to order new handlebars. And depending on how old your machine is, that could be problematic.
It would be helpful if you also posted a pic of your handlebars - that will give an indication of the age of your machine. If it's not too old, you should be able to find another set from either AllBrands.com , or from SewingMachinesPlus.com.
You can PM me if you need help.
Edited to add: You can also find several Tin Lizzie groups on Facebook
Last edited by letawellman; 12-19-2017 at 06:34 PM.