1 Apr
2008
1 Apr
'08
1:41 a.m.
On Mon, 31 Mar 2008, Tony Duell wrote:
I think ticking PSUs in displays are a sign of a shorted HOT and/or
flyback (had this case several times).
Christian
I don;t know what test gear you have, but I find a
simple logic probe to
be more use than a 'scope for this sort of problem. The former can easily
Yes, logic probes are very handy. They are small and easy to use, and I
have found faulty devices most of the times just with the logic probe. The
seven-segment display show transitions and illegal voltage levels (or no
voltage at all), very useful e.g. for dead totem pole outputs (in this
case the voltage of the signal will be determined by the input stage(s)
and lies around 1-2V).
I also return
all systems to working order. Apart from a couple of
VT420's with ticking SMPSU's everything I have restored runs. (Three
Any reason you';ve not fixed those? Ticking SMPSUs are often quite simple
to fix, maybe just dried-up capacitors.