1 Sep
2015
1 Sep
'15
11:27 a.m.
On Sep 1, 2015, at 1:57 PM, tony duell <ard at p850ug1.demon.co.uk> wrote:
Yes it is. I am getting 15V on pin 4 that connects to the collector of TR23.
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? 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