Archimedes A310 PSU Replacement

Arc/RPCs, peripherals, RISCOS operating system & ARM kit eg GP2x, BeagleBoard
VintageMicro
Posts: 10
Joined: Wed May 24, 2017 8:47 pm

Archimedes A310 PSU Replacement

Postby VintageMicro » Thu May 25, 2017 7:44 pm

Just though I would share my A310 PSU replacement

Got the machine cheap in a bundle of old computers, it had a totally blown
power supply and a very corroded AA battery compartment, its also a dual floppy
imagine these were mega expensive back in the late 80's, this one also has
ram expansion and Risc OS Upgrade installed.

Battery compartment was cleaned up with vinegar solution to dissolve the
alkali battery gunk and the contacts cleaned with fine wet and dry paper, and it
now works ok.

A bonus with these flex psu's is the fan pulls in air at the top
and pushes the warm air out the back and fits just about right in the case,
so the original cooling fan can also be removed and give a large
air intake close to the fan when the lid is on, as the case has vents slots on the left.

You need to find a flex ATX or small type PC PSU but you will need
to find one that has a Minus -5 Volt line on the ATX connector, some PC's psu have this wire missing
this is usally a white wire on the PC side and the Purple one on the original Acorn PSU.

The green wire is PS_ON when connected to ground this wire turns the power supply on.

The other connections are +5v Red, +12v Yellow, Black is Ground, all wires were
twisted together soldered and then heatshrinked to stop them shorting.

These acorns are low power, at idle with no hard disk this replacement draws
just 26 Watts so any psu around 100w or more should be fine, the bigger the psu
the less efficient it will be though, the PSU was just £10 from an online IT recycling place
as long as the psu can supply around 3.5 Amps on the 5 Volt line you should be fine as
this is what the original acorn ones are rated to.

I used some epoxy to glue the base of the psu in place and
fitted a side screw to firmly secure it inside the case.

I also had very loose floppy eject buttons, these were easily fixed with
my friend pound-land epoxy glue on the underside of the buttons.

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Last edited by VintageMicro on Thu May 25, 2017 8:00 pm, edited 3 times in total.

Zarchos
Posts: 2355
Joined: Sun May 19, 2013 8:19 am
Location: FRANCE

Re: Archimedes A310 PSU Replacement

Postby Zarchos » Thu May 25, 2017 7:54 pm

Thank you !

hubersn
Posts: 58
Joined: Sun Aug 14, 2016 7:59 pm

Re: Archimedes A310 PSU Replacement

Postby hubersn » Thu May 25, 2017 10:01 pm

VintageMicro wrote:You need to find a flex ATX or small type PC PSU but you will need
to find one that has a Minus -5 Volt line on the ATX connector, some PC's psu have this wire missing
this is usally a white wire on the PC side and the Purple one on the original Acorn PSU.


Is the -5V voltage needed for anything else but the podule bus? I don't remember.

Have fun
hubersn

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IanS
Posts: 459
Joined: Mon Aug 31, 2009 6:02 pm

Re: Archimedes A310 PSU Replacement

Postby IanS » Thu May 25, 2017 10:05 pm

-5V is used in the audio section and the serial port.


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