More switchmode power supply grief - Cisco IGS router

[Peter Coghlan]

What's a "Mean-Well module"?  I somehow find myself imagining:

"I put a new module in my router.  It blew up.  At least it meant well"  :-)

(My IGS has the rather heavy and over-engineered divider shelf with the
main board underneath and the fan and power supply above.)

Regards,
Peter Coghlan

Jonathan Chapman via cctalk wrote:
>
> With that much carnage, I'd probably drop a Mean-Well module in there. I
> believe there would be enough room for one or two in the IGS I have
> (taller white box, divider "shelf" over the mainboard, I don't know if
> there was a lower profile model).
>
> Thanks,
> Jonathan
>
> ------- Original Message -------
>
> On Saturday, February 5th, 2022 at 09:17, Phil Blundell via cctalk <cctalk at classiccmp.org> wrote:
> 
> > On Thu, Feb 03, 2022 at 06:06:10PM +0000, Peter Coghlan via cctalk wrote:
> >
> > > Today I finally managed to check it out. The ceramic F4A mains input fuse
> > >
> > > beside the power switch on the back panel had blown. When I opened it up,
> > >
> > > I found a POWER-ONE MAP80-4000 power supply. The main chopper transistor
> > >
> > > labelled Q1 on the PCB is almost a dead short. It is a large plastic
> > >
> > > packaged FET mounted on a piece of aluminium which is in turn screwed to
> > >
> > > the case for heatsinking. Unfortunately, there are no markings on it so
> > >
> > > I have no idea what to replace it with :-(
> > >
> > > As Q1 is shorted across all three terminals, whatever drives it may be
> > >
> > > damaged too :-(
> >
> > Does that PSU have a PWM controller IC, or is it built entirely from discretes?
> >
> > If there is an IC driving the chopper transistor then you may be able to get
> >
> > some clues about the likely characteristics of the transistor from the IC
> >
> > datasheet. Is it definitely a FET? Some, particularly older, designs used
> >
> > bipolar transistors there.
> >
> > As you say there is a fairly high likelihood that other components on the
> >
> > primary side will have blown up as well so you might be looking at a fairly
> >
> > extensive repair. Are there any other obscure, unmarked devices or is this
> >
> > the only one?
> >
> > p.
>