This subject is vast. It depends on your jukebox first and foremost. If you’ve got an antique then they’ve got to know what they’re doing. My advice would be go back to the place you bought it for help but here are some recommendations.
The jukebox repair company, The Jukebox man (thejukeboxman.com), has a great website with a very helpful Hot Tips page for a methodical process of fault finding when your jukebox goes wrong. Also a great description of modifying your jukebox to Free Play.
Jukebox parts can be purchased from, as mentioned above, The Jukebox Man in the UK. There are several well known companies in the US.
Victory Glass was set up to help the jukebox restoration enthusiast. They claim to have a full line of reproduction parts and used parts.
Another US company is Musical Fun For Everyone. You can request parts and the owner will endeavour to source them for you. He does have a list of other sources on his website.
Vern Tisdale runs a company offering reproduction, used and also sells jukeboxes and their schematics. He is based in Phoenix, Arizona.
There are plenty of jukebox restorers with websites: Jukeboxes Direct (UK), Discomatics (UK), Jooks (UK), Jukebox Services (UK), David Webb Classic Jukeboxes (UK), Antique Jukebox Repair (USA), Retro Rock-It (USA).
Sound Leisure (www.slretail.co.uk) are manufacturers of digital audio, video and CD jukeboxes. They are handmade and based on classical designs. The sole UK manufacturer of jukeboxes and was founded in 1978. Their products are high quality, they offer training days for installation and provide support to owners. Their website also has a list of their European distributors.
Rowe AMi has produced over one million jukeboxes. According to their website they boast the broadest product range available so they might be the first port of call for any unusual commercial spaces or themes.
Rock-ola is the place to go for an authentic American-made jukebox. The Nostalgic Bubbler or the Peacock Touchscreen Music centre are at both ends of the timescale but equally mesmerising!