H7861 PSU issues

[Adrian Graham]

>I was also quite surprised that such a simple component would die,
>and what I find more confusing is that it died while I was using
>the machine.

A 555 can also take a Commodore PET down because it's solely in charge of
the RESET circuit, and no RESET == no PET.

On 2 November 2017 at 14:22, Aaron Jackson via cctalk <cctalk at classiccmp.org
> wrote:

> Thanks! It was very satisfying and not the worst thing to go wrong
> for a beginner.
>
> I was also quite surprised that such a simple component would die,
> and what I find more confusing is that it died while I was using
> the machine.
>
> Aaron.
>
> Noel Chiappa via cctalk <cctalk at classiccmp.org> wrote:
>
> >     > From: Aaron Jackson
> >
> >     > Picked up a few 555s and sockets and now it works!
> >
> > Congratulations!
> >
> > It's odd that a 555 failed, but sometimes there's no rhyme or reason to
> what
> > fails. E.g. I was fixing some broken M7859's (KY11-LB Programmer's
> Console),
> > and on one of them a 7493 (4-bit counter) had died. That's not one of the
> > 'problem' 74xx chips, like ISTR the 7474 being?
> >
> >       Noel
>



-- 
adrian/witchy
Owner of Binary Dinosaurs, the UK's biggest home computer collection?
www.binarydinosaurs.co.uk