Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Princeton Ultra 72e Monitor

Purchased this monitor as upgrade less than 3 yrs ago (still under warranty.) Have had 4 failures within several weeks of installation. System used exclusively by 86 year old retired person, not subject to abuse or heavy use. Since we cannot act as 24 hour a day on-site troubleshooters, are now seeking to purchase a replacement monitor, even though this is still under warranty. Princeton claims there are no problems with this monitor. We are wondering if they are shipping refurbished monitors under the warranty (charging $80+ shipping each time)? Spouse is purchansing mgr for computer system builder and knows the hardware. This is the most frustrating situation we have encountered in years!