🚀 go-pugleaf

 "Stupider than Anyone Else"

> Phil was only on about the voltage rating issue.

**  Massively wrong presumption.


> It's credible, given that there was no sign of distress, but it's odd that 
> Q1 was taken out as well. I still can't see a mechanism for that, which is 
> why I was somewhat surprised that the repair worked.


** Ignorance is neither a virtue nor ever a basis to argue from.

 Learn that and you will be an entirely better person.

 Shame how no-body can teach old bitches new tricks.


> Well, you wouldn't if they've been correctly specified. Phil was 
> essentially arguing that I could substitute a component with a lower 
> voltage rating.


**  Massively wrong presumption.


> Instead, my aim was to reproduce the original resistance, within the 
> tolerance chosen by the designer, to minimise the chance of destabilising 
> the circuit, while preserving a safe failure more should the transistor 
> fail shorted. In this context, by safe I mean a failure mode that would 
> have a fair chance of protecting the upstream components, thus leaving the 
> board in a repairable state.


**  The fusible resistor in question is there  ONLY  to prevent the PCB 
material catching fire  -  as might occur if a non fusible type were used  - 
cos they can act like an incendiary.

A more accurate name for fusibles is " flame proof " types  -  as described 
in your link.

Protecting delicate parts like semis is not part of their job description - 
at all.

BTW:

You came here for the advice of folk with experience of electronics,  cos
you have absolutely none.

The advice I gave is based on many decades of ACTUAL experience.

If you simply replace the fusible resistor in the PSU with a similar part,
then it will perform just as well as the original one did.

There is a HUGE amount of electronics YOU have no clue about.

Nor any other fucking thing either.





.....   Phil