The output voltage stability, input power increases (eg when entering 220V, input power of about 50W with input voltage rises, when the input voltage rises 260V, 60W input power will rise above normal should still be 50W left). This is a transformer with a ferrite material does not meet the requirements, if the power to do this routine test, after 8 hours of continuous work, the power will be burned. Thus, where a case of power transformer T must be replaced.9vdservice manual download site