Replacing Power LED on MicroVAX 3100/95 Power Supply

Rob Jarratt robert.jarratt at
Wed May 13 01:23:03 CDT 2020

That's fantastic Maciej! I often buy from Farnell, so there is no issue with
getting those parts myself. When I have accumulated enough wants to warrant
an order I will get them.



> -----Original Message-----
> From: cctalk <cctalk-bounces at> On Behalf Of Maciej W.
> via cctalk
> Sent: 13 May 2020 02:41
> To: Peter Coghlan <cctalk at>; General Discussion: On-Topic
> and Off-Topic Posts <cctalk at>
> Subject: Re: Replacing Power LED on MicroVAX 3100/95 Power Supply
> On Sun, 10 May 2020, Peter Coghlan via cctalk wrote:
> > > I seem to remember people saying it is quite difficult to replace
> > > these, mainly because you can't get them out without breaking the
> > > holder. Is that right? Has anyone done this successfully and have any
> >
> > Is this the green LED in a H7821 PSU? I managed to get one out of the
> > holder with a bit of difficulty before I realised I could have left it
> > in place and the board can just about get past it when the plug at the
> > far end of the leads feeding it is plugged out from the board.
>  If the holder is the same as with the H7826 PSU, then it's a generic part
> manufactured.  I bought whatever was the minimum quantity sold by Farnell
> when I broke one along with the LED a few years ago.  I still have a few
> available and I could post one set once I am back to my UK home (which is
> given the current situation regrettably not going to happen anytime soon).
> Otherwise you can order it yourself:
> <
> 5mm-led/dp/8576378>.
> > > Are there any recommendations for a replacement? If I remember
> > > correctly the LEDs used in those days were not as bright as modern
> > > ones and a modern one would end up being much brighter because of the
> higher voltage maybe?
> >
> > Maybe it would be possible to tack blobs of solder onto what's left of
> > the leads on the original and use them to attach fine leads, digging
> > out a small amount of the LED casing around the leads if necessary?
>  I chose an LED matching the original colour, also of the case, as closely
> possible:
> <>, but
> haven't installed it (well, ahem, I need to fix the PSU itself first), so
I can't
> comment on the result.  I could post one of those along with the holder if
> needed (subject to the condition noted above).
>  An LED will dim with use, so you may not be able to closely match a worn
> with a brand new part, but I suppose you don't actually need to be
> *that* exact with your equipment, do you?  Otherwise you can always put a
> resistor in series to dim the light produced.
>  HTH,
>   Maciej

More information about the cctech mailing list