1 Dec
2005
1 Dec
'05
3:59 a.m.
lee davison wrote:
Interesting - I suppose in all the SMPSU failures I've seen in the past where
the switching transistor(s) has gone, it's failed O/C and so nothing else has
been affected. Can't remember the last time I saw the top get blown right off
an IC!
At least *if* it's just the switching transistor and this IC that are dead
then repairing without schematics shouldn't be too hard. Depends what else
shares the IC output and hence has been given a blast of mains to it...
cheers
Jules
So, given that
assumption for now, anyone know of a likely fault
in a typical SMPSU that might cause such a catastrophic chip
failure but no other obvious damage?
The switching transistor has probably gone s/c which ends up
connecting the rectified mains to the switch output on the IC.
They tend not to last long when that happens.