The clicking means the compressor is dead. If under warenty have them replace the whole thing. If you ever hear that clicking you wont be able to replace it on site. Its not very hard to replace a compressor if you have a torch and the parts but if you are new to it Id just get a new of refurb one.
You know of any place that you could sell the old compressor assembly to (just to offset the cost), or are you better off just buying it from somewhere else? I also saw some used ones for sale for around $199 (www.premiervending.com), anyone know anything about this company? Or you better off just buying refurbed? Or could you just take the whole assembly out and take it somewhere for them to fix it?