6 Feb
2022
6 Feb
'22
3:43 p.m.
"Maciej W. Rozycki" wrote:
On Sat, 5 Feb 2022, Peter Coghlan via cctalk wrote:
I've checked their web site and they continue to offer a MAP80-4000G,
which I suppose is just a minor update from the original, and is visually
the same, as it seems from the datasheet dated 2021. So I'm fairly sure
they have all the data. Those discrete semiconductor components do not
change much, I was able to order exact replacements for another faulty
device from 1990s a few years ago.
They may offer you a paid repair or replacement service or if you're kind
enough and they are reasonable, they may identify the single part for you.
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.
Regards,
Peter Coghlan.
This PSU
seems to have been used across various Cisco devices and I had
one fail several years ago in a WS-C1202 Ethernet/FDDI switch, also having
suffered from leaking caps. Back then RS still had it in stock at a hefty
price of ?489.60: <https://uk.rs-online.com/web/p/products/8338173/>, so I
chose to recap the failed one and thanfully it has continued working ever
since. You may try to enquire with the manufacturer.
Good luck with bringing yours back to life!
Thanks Maciej. I'll be surprised if the manufacturer has records of
what they used for the chopper in power supplies 30 years ago - who
knows if their design has changed between then and now. I'll be even
more suprised if they will talk to me about it but I guess it's worth
a try. Good luck!
Maciej