On Sep 1, 2015, at 1:57 PM, tony duell <a...@p850ug1.demon.co.uk> wrote:
>> >> Hmm, you are right, I am not seeing any spikes in voltage there. On >> the collector of the TR23 all I am getting as DC voltage is around >> 110mV. The oscilloscope tells me I am getting Vpp of about 4.4V with >> Vmax at 2.6V and Vmin at -1.8V and an average of 105mV (which matches >> what my multimeter tells me too). >> >> That sounds too low doesn't it? > > That is far too low. > > Firstly, there should be a 12V or so feed to one pin on the flyback primary > winding (the winding that links to the collector of TR23). Is that present > and > correct? Yes it is. I am getting 15V on pin 4 that connects to the collector of TR23. > What about other components connected to that winding. There is a diode and a capacitor. They both measure 300mV or so. The diode seems to be working. I will desolder one leg of the capacitor and check it too. I do not have an ESR meter so I will do normal checking. > > Are you sure TR23 is good. The horizontal output transistor in many monitors > often fails. I am not sure. I assume I have to desolder it to check it right? Regards, Vlad > > -tony