More switchmode power supply grief - Cisco IGS router

[Maciej W. Rozycki]

On Sun, 6 Feb 2022, Peter Coghlan via cctalk wrote:

> >  NB Mouser has the MAP80-4000G in stock actually, so if all else fails and 
> > you are determined to get the IGS running, you can pick a brand new one: 
> > <https://www.mouser.co.uk/ProductDetail/784-MAP80-4000G>.
> > 
> 
> Thanks again Maciej.
> 
> I've bit the bullet and unsoldered most of the electrolytic capacitors and
> other components that seem to be in trouble.  When I got the chopper
> transistor out, I found that if I hold it at exactly the right angle to
> the light, I can see that there are faint markings on it after all and it
> turns out to be an IRFPE50 HEXFET.  I was wrong about the cracked RIFAs
> not being mains filters too, they are actually across L-E and N-E and
> they seem to have between a few hundred kOhms and a few MOhms leakage too.
> The driver transistor looks like it might be ok.

 It seems like great progress!  Yes, those etched markings are sometimes 
hard to decipher, requiring looking at the correct angle with light coming 
from the right direction too and/or techniques used to take fingerprints 
at a crime scene.  With these details known you may be able to actually 
get this sorted just by yourself.  Good luck again!

  Maciej