"Jim Yanik" bravely wrote to "All" (03 Jan 05 17:07:22)
--- on the heady topic of " ticking smps"

JY From: Jim Yanik .
JY Xref: aeinews sci.electronics.repair:5701

JY BigTom wrote in :
how can i fix a ticking smps on a mitac L1450PD
it uses a UC3842 controller CNX82A optocoupler and TL431A shunt.
there are four lines on this monitor, 150v 87v 24v 6.3v all reading low.
how do i find the line causing the problem?


JY ticking indicates the PS is trying to start,but tripping a protective
JY current limit.

JY I'd check for shorted diodes on the secondaries and use an ESR meter
JY to check the electrolytics.


Weak switching pass transistors can also result in ticking though the
psu might even start intermittantly but the regulation will be poor.

A*s*i*m*o*v

.... If all else fails, hurl it across the room a few times!