30 Nov
2005
30 Nov
'05
8:16 p.m.
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.
Lee.
..
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1 Dec
1 Dec
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.
6727
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6727
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julesrichardsonuk＠yahoo.co.uk -
leeedavison＠yahoo.co.uk