On 2010-10-07 07:55:49 +0200, "Michael Kennedy" mike@com said:

Sorry if this is a bit of a novice question...

I have a SMPS in Plsama tv which upon powering up starts clicking...
It seems to do it as it warms up or the load changes on the psu (screen
going dark or getting light)

As far as I can tell it isnt any relay doing this, even though It
sounds like a relay.

Ticking alone I could live with, although a bit annoying but the PSU
also occasionally shuts down when cold. I am not 100% sure what is
clicking.. The clicking noise seems to be coming from different
locations at dfferent times, even possibly the X or Y sus boards.

I have sprayed the whole thing down with freeze spray to no avail... It
is built with PBF solder, so I guess bad solder joints are likely issue
also.

I have changed the obvious capacitors near heat sources excpet the two
large 400v 250uf filter caps.. Removed and checked the filter caps and
they checked good on my ESR meter.

Any Idea what would be clikcing? Here is the board layout
https://sites.google.com/site/chibamikey/PSU.JPG

I would change the main 400v capacitor
clicks means this capacitor is almost dry ...
regards,
--
-
Jean-Yves