More switchmode power supply grief - Cisco IGS router

[Jonathan Chapman]

Mean-Well is a maker of drop in power supplies. They sell a wide variety of sizes and output configurations. The supplies are (mostly) not expensive, though not as cheap as something you might dig up on e.g. AliExpress. They also won't burn your house down :)

The name is rather unfortunate.

All of the big part suppliers carry them. I have had better luck hitting the Mean-Well site and figuring out what I need, then searching the model # on e.g. Mouser. Often, it is cheaper to use two modules rather than finding one do-all with the current ratings you need, but the IGS should have fairly straightforward power requirements.

Sounds like we have the same kind of IGS!

Thanks,
Jonathan

------- Original Message -------

On Saturday, February 5th, 2022 at 17:17, Peter Coghlan via cctalk <cctalk at classiccmp.org> wrote:

> 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.