The Caribbean falls under Epson Latin America and according to their website you get one year on-site: http://global.latin.epson.com/Catalog/Epson-Stylus-Pro-4900/Tech-Specs
My understanding is that anywhere Epson sells printers, even in Qatar, Bolivia, Ethiopia, Brazil, where ever... Epson warrants their printers for one year. There is nothing particularly different about Latin America or the Caribbean. What is so peculiar about your situation that your printer is not warrantied in the Caribbean? Take a look at the page above from your Epson Global Territory - it plainly says one year - on site repair. You should push back. Call the regional office. They answer to America office in LA. Ultimately North and South America are run from LA. But Latin America runs the Caribbean. So just move up the chain until you get someone who will replace the printer or perform the on-site.
To answer your questions, you will absolutely need the 4900 Field Service Manual in order to know what part you need and how to replace it. You will need to take it apart to find out what broke. You can buy and download this manual from 2manuals.com Do not attempt to further repair your printer without the Field Service Manual as you can severely damage your printer. But I do not suggest that you do this. As soon as you remove the covers - you will void your warranty and ruin any chance of getting an on-site repair. The warranty clearly states that. Compass Micro is the Epson USA Authorized distributor for Epson parts for USA customers - but I do not know if they sell outside the USA. You may need to contact Epson Latin America to find their Authorized parts distributor.
It's 1am here and we are supporting you as best we can. I am still sorry that you did not contact us on the weekend.