Hi Greg,
The unit does come with a maintanance contract, and you can take out an extended warrenty also.
As for as failures, the only ones I have encountered are:
1. Not enough of a sample. Since the unit calibrates itself with every test, it draws blood into 3 chambers, calibrates, then uses the other 2 chambers to evaluate your INR. I like this because it does calibrate with every test. When I first started using the ProTime, I got nervous and didn't provide enough blood, so I got the error. I haven't had that error in well over a year now.
2. Got an error due to bubbles in my sample. Again, this only happened when I first started using the unit. I now know how to provide my sample correctly, and this error has not resurfaced in almost 2 years.
3. Low Battery. I guess I pushed the limits of the unit. I rarely keep my unit plugged in. I use the battery mostly. So, for this error I blame on myself.
Thats it. So, overall, the the 2 years that I have been using the Protime, I have not complaints. In fact, I would recommend this unit to anyone on the site.
Best regards,
Rob