[rescue] IPX modern PSU (hanshuebner)

[Daniel Williams]

Have you tried starting that specific IPX with the recapped original PSU?
I wouldn't think the 12V supply being slightly low would cause it to not
boot.

~Daniel

On Wed, May 27, 2026, 06:23 vom513 via rescue <rescue at sunhelp.org> wrote:

> Hello all,
>
> First a bit of admin/update:
>
> Original project (now RO):
>
> https://github.com/hanshuebner/ipx-psu-replacement
>
> New home:
>
> https://code.netzhansa.com/hanshuebner/ipx-psu-replacement
>
> On that note - the new site doesn’t seem to allow creation of a user
> account (it’s a “private hosted” platform ?). I reached out to him via the
> email listed on Github and no reply yet hence posting here…
>
> I built one of these a ways back - and originally it seemed to work.  Now
> it doesn’t.  The behavior is that the IPX chimes and gets a green power LED
> - but never any video.  I’m guessing that the system is never “turning
> over” (i.e. CPU at least).
>
> On the bench - I notice that the +12 is actually 11.7.  +5 / -12 seem
> okay.  Real Sun PSU (recapped) gives me a hair over 12.  hanshuebner will
> power up and supply voltage with no load.  Original Sun won’t (I connected
> an old Seagate 1G SCSI to molex to get it to come up).  Technically the
> MeanWell 12v module in the hanshuebner is in spec I think (+/- 3% ?).
> Regardless a data point in comparing the new vs. old.
>
> A few more notes on my particular IPX:
>
> - I have a PowerUP 80mhz CPU
> - I have the (officially not supported) 501-1823 32mb memory SBUS card
> - I do not have an internal HDD.  I run from an external (and externally
> powered) ZuluSCSI
>
> So finally I was wondering if anyone who has built this has any insight or
> general electronics insight to what I am seeing.
>
> My only two stabs in the dark are that the 11.7 vs. >= 12 is an issue.
> Also the SENS line (which is connected) could have an issue ?.  Beyond that
> I have no idea what it could be or what to test.  I have thoroughly
> inspected the board for bridges / bad solder / blown caps etc.
>
> Thanks.
>
>
> _______________________________________________
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>
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