Modern China tridonics

These more modern China Tridonics are becoming a real problem for me, I am trying to keep fluorescent going this is not helping my cause! The tubes I installed at the time I replaced the ballast in these fittings are hardly even worn yet the ballast has failed. No sign of dry joints no sign of failed components just dead. I have gone to Philips now for the last couple of years with no problem. The annoying thing about these tridonic ballasts is that for for first few years they seemed quite good so I went on installing hundreds of them now they are dropping like flies!