H7874 power supply

[Rob Jarratt]

I have some notes I made about trying a PC PSU, I don't think it really worked, there are signals to indicate power OK and perhaps others. But perhaps a more concerted effort might yield something that could work.

Regards

Rob

> -----Original Message-----
> From: cctech <cctech-bounces at classiccmp.org> On Behalf Of Robert
> Armstrong via cctech
> Sent: 29 March 2020 19:15
> To: 'Maciej W. Rozycki' <macro at linux-mips.org>; 'General Discussion: On-
> Topic Posts' <cctech at classiccmp.org>
> Cc: rob at jarratt.me.uk
> Subject: RE: H7874 power supply
> 
> >Maciej W. Rozycki <macro at linux-mips.org> wrote:
> >numerous Chemi-Con SXF parts scattered across all boards, some leaking
> 
>   Yeah, mine is full of "Nippon Chemi-Con" electrolytic too.
> 
>   What about just gutting the PS chassis and sticking in an ATX power supply?  I
> don't know how the maximum current per output breaks down, but as I
> understand it the H7874 is only a 600W supply.  That's not a problem for an
> ATX supply, and it would have all the required output voltages.  You'd have to
> run the cabinet fans at a fixed speed and you'd lose the power control bus
> feature, but that's not a show stopper.
> 
>   Actually my unit is in an R400x chassis full of RF drives, so I believe I only need
> +12 and +5.  I don't think the 3.3v and -12 are used in that case.  I wonder how
> much current I really need for the drives?  I should look that up and I might be
> able to find a surplus dual output supply that would do the job.
> 
> Thanks again,
> Bob