"Michael Karas" wrote in message
...
[This followup was posted to sci.electronics.repair and a copy was sent
to the cited author.]

In article , says...



Is there a "bleed-through" route for start-up?

I do not really know what you are asking about here.

Its common practice for the SMPSU control chip Vcc to come from an extra
winding on the chopper transformer. Before the PSU starts up - there has to
be some source of Vcc to get it kick started.

Very often there's a high resistance resistor (or 2 in series) from the +ve
of the mains bridge to provide the initial start up supply for the control
chip - these resistors are very prone to going high/OC.