A4000 PSU Fan mod

alexh · 24 May 2011, 09:10

I'm prepping 3 * A4000D units for private sale and part of the prep work is a complete refurb and test of all 3 units.

I fired two of them up last night and OMG the noise from the PSU fans was almost unbearable.

So I opened them up, (whoever designed the release mechanism for the A4000 faceplate needs to be shot!), I whipped out the PSU's (two were the more powerful Liton's and the last a Skynet) and opened them up.

After removing the 2 tonnes of dust and crap inside them, scrubbing the fan blades with an old tooth brush the noise levels were no better

I have to assume that either the original fans were just cheap & nasty and always made this noise, OR they are just past their sell by date.

We had a load of akasa 80mm 12v fans sitting in a box at work which came "free" with heatsinks we buy. (Hopefully they will blow in the right direction because they only have screw holes on one side!)

Problem is that to save money the CBM spec for the PSU has the fan soldered to the PSU motherboard.

10 minutes later the fans are desoldered and the motherboard PSU's are sporting their new fan pin-headers.

A liton and Skynet PSU side by side

Sporting their new Pinheaders

Two fans for the bin and new ones fitted.

Hewitson · 24 May 2011, 09:34

Nice job

Nothing more annoying than a noisy fan.

zipper · 24 May 2011, 10:48

Quote:

Originally Posted by alexh

I have to assume that either the original fans were just cheap & nasty and always made this noise, OR they are just past their sell by date.

At least mine was equipped with a sleeve bearing that had developed a vast play into it and was noisy as ....

alexh · 24 May 2011, 11:05

Job isn't done until the PSU's are re-assembled and the A4000's are working once powered back on.

If there is anything I've learned over the years is that big-box Amiga's tend to be critical patients, regardless of their wounds. Open them up and they can easily die on the table.

DarrenHD · 25 May 2011, 04:12

Quote:

Originally Posted by alexh

Job isn't done until the PSU's are re-assembled and the A4000's are working once powered back on.

If there is anything I've learned over the years is that big-box Amiga's tend to be critical patients, regardless of their wounds. Open them up and they can easily die on the table.

I replaced the fans in both of mine too with modern 80mm quiet fans...I also cut out the metal cage to add some windows and improve airflow out the back.

http://www.amiga.org/gallery/index.php?n=2266

My PSU's are the Skynet ones I think, (the one in the right of your photo with the LiteOn and Skynet side by side).

Which one is better?

I'm powering a Cyberstorm PPC, Mediator with a bunch of cards and an IDE cdrom and hard disk...works ok with the Skynet PSU.

Darren

Hewitson · 25 May 2011, 04:23

I'd have thought the Lite On would be slightly better quality, at least they're a fairly well known brand.

rkauer · 25 May 2011, 08:00

@Alexh: those CPU only blows in the screw holes direction (they will blow air into the wrong direction).

You may use they, but bolted to the back of the PSU case or bolted outside the PSU cage.

squidbass · 31 May 2011, 09:25

@alexh

How did your fan mod go? Did you manage to re-assemble the psu?

Squid

alexh · 31 May 2011, 12:24

Quote:

Originally Posted by squidbass

Did you manage to re-assemble the psu?

Of course. They are very, very easy to take appart and reassemble.

The hardest thing is getting the motherboard connector in and out without damaging the A4000d motherboard. It needs a stoopid amount of force to get it out. If I was doing this again I think I would have looked for an alternative way to test the PSU rather than plugging and unplugging it 10+ times

The next hardest thing is removing the A4000D faceplate, whoever designed that mechanism needs to be shot. If you have a set of angled needle nosed pliers it gets easier but still crazily hard.

rkauer was correct and those fans blew in the wrong direction so I had to buy a different 80mm fan. I went to my local shop and bought the cheapest "silent" 80mm fan which was an Akasa AK-182-L2B (£3)

But the damn thing is as noisy as the original ones!!

So last week I ordered one for £7 online, a Coolink SWiF2-80P. At 7dba (vs 18dba of the Akasa) It has the lowest noise per unit airflow of any 80mm fan I could find. I'll let you know how it works out tomorrow.

rkauer · 31 May 2011, 22:14

Alexh, did you see this thread on Amibay?

There are a few options you can do using the original PSU as well.

alexh · 31 May 2011, 22:55

Erm, thanks. The original A4000 PSU is more than I could ever need.

All I wanted was to "silence" the fan noise from the old, cheap worn out dust encrusted monsters.

Modding for modding sake is not my thing.

With hindsight I would have quadrouple checked the airflow values. The new SWiF2 fan is completely silent at the fastest (1100 RPM) setting but the airflow feels like a fraction of the original one.

Loedown · 31 May 2011, 23:45

With most PSU modern or antique, they seem to need a fan only in extreme cases. For the most part I have seen some computers that ran quite happily for many years with a dead fan in the PSU. I don't recommend this only state a fact.

alexh · 31 May 2011, 23:50

Yeah, I don't think the PSU electronics needs the airflow but with this being an A4000d-CR it has both a 68030 and 68060 powered at the same time. (Pretty sure the design does not remove power to the onboard CPU when there is a SLOT CPU fitted?)

I'll put it back together and put a thermal probe in there and run it for a bit.

8bitbubsy · 01 June 2011, 03:28

The problem is that the fan header in the PSU is delivering 12v, and this is interpret as "max" to the fan. Try cut the 12v trace and find a 5v and jumper it to the pin, or get a resistor to limit the current a bit. I did this mod to my Amiga 2000 PSU, and the only solution was the resistor (12v = super noisy, 5v = almost no spin at all, resistor = perfect).
Even cooler would be to find a trimmer resistor (pot) and drill a hole for it in the PSU case -- which results in super cool user-adjustable fan speed!

alexh · 01 June 2011, 09:04

The new fans are silent at 12v and they have a PWM controller with 3 settings built in.

hooverphonique · 01 January 2013, 14:31

Quote:

Originally Posted by Hewitson

I'd have thought the Lite On would be slightly better quality, at least they're a fairly well known brand.

The A4000 PSU is *not* by the LiteOn brand.. It's called 'TAIWAN LITON'

24 May 2011, 09:10	#1
alexh Thalion Webshrine Join Date: Jan 2004 Location: Oxford Posts: 14,342	A4000 PSU Fan mod I'm prepping 3 * A4000D units for private sale and part of the prep work is a complete refurb and test of all 3 units. I fired two of them up last night and OMG the noise from the PSU fans was almost unbearable. So I opened them up, (whoever designed the release mechanism for the A4000 faceplate needs to be shot!), I whipped out the PSU's (two were the more powerful Liton's and the last a Skynet) and opened them up. After removing the 2 tonnes of dust and crap inside them, scrubbing the fan blades with an old tooth brush the noise levels were no better I have to assume that either the original fans were just cheap & nasty and always made this noise, OR they are just past their sell by date. We had a load of akasa 80mm 12v fans sitting in a box at work which came "free" with heatsinks we buy. (Hopefully they will blow in the right direction because they only have screw holes on one side!) Problem is that to save money the CBM spec for the PSU has the fan soldered to the PSU motherboard. 10 minutes later the fans are desoldered and the motherboard PSU's are sporting their new fan pin-headers. A liton and Skynet PSU side by side Sporting their new Pinheaders Two fans for the bin and new ones fitted. Last edited by alexh; 03 January 2013 at 13:02.

31 May 2011, 22:55	#11
alexh Thalion Webshrine Join Date: Jan 2004 Location: Oxford Posts: 14,342	Erm, thanks. The original A4000 PSU is more than I could ever need. All I wanted was to "silence" the fan noise from the old, cheap worn out dust encrusted monsters. Modding for modding sake is not my thing. With hindsight I would have quadrouple checked the airflow values. The new SWiF2 fan is completely silent at the fastest (1100 RPM) setting but the airflow feels like a fraction of the original one. Last edited by alexh; 31 May 2011 at 23:09.

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24 May 2011, 09:34	#2
Hewitson Registered User Join Date: Feb 2007 Location: Melbourne, Australia Age: 41 Posts: 3,773	Nice job Nothing more annoying than a noisy fan.

24 May 2011, 11:05	#4
alexh Thalion Webshrine Join Date: Jan 2004 Location: Oxford Posts: 14,342	Job isn't done until the PSU's are re-assembled and the A4000's are working once powered back on. If there is anything I've learned over the years is that big-box Amiga's tend to be critical patients, regardless of their wounds. Open them up and they can easily die on the table.

25 May 2011, 04:23	#6
Hewitson Registered User Join Date: Feb 2007 Location: Melbourne, Australia Age: 41 Posts: 3,773	I'd have thought the Lite On would be slightly better quality, at least they're a fairly well known brand.

25 May 2011, 08:00	#7
rkauer I hate potatos and shirts Join Date: Oct 2007 Location: Sao Leopoldo / Brazil Age: 58 Posts: 3,482	@Alexh: those CPU only blows in the screw holes direction (they will blow air into the wrong direction). You may use they, but bolted to the back of the PSU case or bolted outside the PSU cage.

31 May 2011, 09:25	#8
squidbass Registered User Join Date: Sep 2007 Location: Southport The Last Resort Posts: 202	@alexh How did your fan mod go? Did you manage to re-assemble the psu? Squid

31 May 2011, 22:14	#10
rkauer I hate potatos and shirts Join Date: Oct 2007 Location: Sao Leopoldo / Brazil Age: 58 Posts: 3,482	Alexh, did you see this thread on Amibay? There are a few options you can do using the original PSU as well.

31 May 2011, 23:45	#12
Loedown Precious & fragile things Join Date: Feb 2009 Location: Victoria, Australia Posts: 1,946	With most PSU modern or antique, they seem to need a fan only in extreme cases. For the most part I have seen some computers that ran quite happily for many years with a dead fan in the PSU. I don't recommend this only state a fact.

31 May 2011, 23:50	#13
alexh Thalion Webshrine Join Date: Jan 2004 Location: Oxford Posts: 14,342	Yeah, I don't think the PSU electronics needs the airflow but with this being an A4000d-CR it has both a 68030 and 68060 powered at the same time. (Pretty sure the design does not remove power to the onboard CPU when there is a SLOT CPU fitted?) I'll put it back together and put a thermal probe in there and run it for a bit.

01 June 2011, 03:28	#14
8bitbubsy Registered User Join Date: Sep 2009 Location: Norway Posts: 1,710	The problem is that the fan header in the PSU is delivering 12v, and this is interpret as "max" to the fan. Try cut the 12v trace and find a 5v and jumper it to the pin, or get a resistor to limit the current a bit. I did this mod to my Amiga 2000 PSU, and the only solution was the resistor (12v = super noisy, 5v = almost no spin at all, resistor = perfect). Even cooler would be to find a trimmer resistor (pot) and drill a hole for it in the PSU case -- which results in super cool user-adjustable fan speed!

01 June 2011, 09:04	#15
alexh Thalion Webshrine Join Date: Jan 2004 Location: Oxford Posts: 14,342	The new fans are silent at 12v and they have a PWM controller with 3 settings built in.

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