I was in Aircraft Spruce in Corona, California a month ago, they used to sell ZAON products, Another customer asked the guy behind the counter where he could get his XRX fixed ( I have one also so I was earywigging in case mine packed up), the guy basically said with ZAON being out of business he has had many requests for repair and is unaware of anyone who fixes them and that his best advice was to look on the internet for the few remaining ones offered for sale on ebay etc, or start planning on moving to ADS-B equipment. So the takeaway i got from that is if mine packs up I'm knackered, which is a pity as it's a cheap and effective piece of equipment.