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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: Clark Kent on October 29, 2010, 02:31:41 PM
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Hi,
Just a thought. I like silent computing and my Amiga 4000 has a power supply fan blowing air the wrong way. It's a known problem that quite a few A4000s are constructed this way, the fan is blowing hot air into the power supply and not out of the chassis.
Now, my questione is this: is it a very bad idea to just remove the fan completly? This A4000 is quite cold, the CPU is a 68060 (CyberStorm MK2) clocked at 50 Mhz. What risk would I be running? I guess the 68060 wouldn't overheat, but what about the power supply?
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I think with no air moving, it'd get hot in there.
The power supply itself should have a fan, but even blowing backwards, it's still moving air around in the case.
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These old computers have enough trouble as it is, use a fan to move a little air atleast.
Get a near silent fan for a PC and just wire it in. Some of them are 5v instead of 12v, so make sure before you wire it up.
I did this to mine when I put in a small atx power supply and it's effectively silent.
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When I had a real 4000D PSU, the fan was sucking air from the inside of the chasis and forcing it out the vent in the back. I had two problems: that the 4000D fan is throttled by a resistor, and the cards (X-Surf and P-IV) were generating too much heat and not enough airflow.
Resolving the first did not fix the second. I bypassed the resistor to increase fan speed (replacing the fan helps, too, as those things get ratlly and noisy in old age, as many of us do,) but the case remained hot to the touch. My next magic trick was to put a vented spacer in the back, which reduced the heat in the case dramatically.
The spacer was actually the mounting bracket for one of those slot fans which tend to seize up after a few days of use. I do not recommend using a slot fan as it will fight against the exhaust fan in the PSU. I tried one at first and it helped with the card area, but the hard drive side of the case stayed really hot. Designs I have seen of the 4000 show the airflow is supposed to come in across the cards, flow around the front, across the CPU card, then out the PSU.
In the end modifying the PSU did not matter much as I replaced it with a min-ATX PSU, which has worked wonderfully (I believe I have a picture in my gallery.)
For what it is worth, the original PSU fan modification was not unbearably loud -- it was not silent, but it was not obnoxious. The mini-ATX is effectively silent.
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Hi,
Just a thought. I like silent computing and my Amiga 4000 has a power supply fan blowing air the wrong way.
Back when they came out, that was a big problem for people in some regions. I remember usenet posts from people in Australia that could not use their new A4000D's in the summer! If you are in Norway, could be a different situation. I know Sweden had to retrofit the coastal patrol submarines they exported to middle eastern countries to add air conditioning - they had never even thought about AC when using them off Sweden, they needed heating.
The stock A4000D ps CBM bought is junk, although many are still running. LoadWB is right - the only limitation is form factor, there is only so much room inside the case. I mounted my replacement -behind- the case, behind where the ps normally goes, and used a cantilever system to support it. This consists of, on top, two steel bolts with curved hooks on one end to catch the back of the ps, and the threads and nuts on the other tensioning (is that a word?) it unto the case. The ps fan still draws air through the case, and now I can use just about any supply I can find. I should post a picture.
Years ago, when I had too much time on my hands, I made my A4000D totally silent. I got a bunch of surplus Linear DC power supplies, one for each needed voltage, probably from old minicomputers. Each one was half as big as my A4000D, and twice (or more) as heavy, and I needed three (+5V, +12V, -12V). Put them on a shelf below and used automotive starter cable (big as your finger or thumb) to get the power to the motherboard. These supplies had big fins for passive cooling , no moving parts! Left the case off the Amy :) Was wonderful, but when time came to move, I could not take the beast of a setup :( Went back to ATX setup described above.
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I changed my supply fan years ago into a low noise PC fan and the noise level went down by a wide margin.
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I found the picture of my ATX PSU.
http://www.amiga.org/gallery/index.php?n=2720
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Thanks everybody for the help. I think the way to go is to replace my PSU fan. Just to get this right, this should be a 120 mm x 120 mm 12 V fan? You can easyly find fans like this that only do 15 dB!
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One more question. The A4000 PSU fan has only two connectors, right? New fans have three: red, black and yellow (ground?). What to do with the last connection, just ignore it?
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the yellow one is for fan controll so you dont need it.
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Thanks everybody for the help. I think the way to go is to replace my PSU fan. Just to get this right, this should be a 120 mm x 120 mm 12 V fan? You can easyly find fans like this that only do 15 dB!
The A4000D fan is an 80mm fan. I bookmarked some really quiet fans at home, and will try to remember to post them here. I found the fans in this very forum somewhere, after digging around for a few hours.
slaapliedje
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I removed the fans in both of my A4000 PSU's (liteon and skynet) and replaced them with SWiF2-800's with rubber grommits which made them almost silent with "almost" the same CFM airflow as the original.
http://www.quietpc.com/cl-swif2-800
I was a bit worried that the airflow might be less with them being so much quieter but I've not had problems.
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I removed the fans in both of my A4000 PSU's (liteon and skynet) and replaced them with SWiF2-800's with rubber grommits which made them almost silent with "almost" the same CFM airflow as the original.
http://www.quietpc.com/cl-swif2-800
I was a bit worried that the airflow might be less with them being so much quieter but I've not had problems.
cool link still works for these quit fans:)
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Hi,
Just a thought. I like silent computing and my Amiga 4000 has a power supply fan blowing air the wrong way. It's a known problem that quite a few A4000s are constructed this way, the fan is blowing hot air into the power supply and not out of the chassis.
Now, my questione is this: is it a very bad idea to just remove the fan completly? This A4000 is quite cold, the CPU is a 68060 (CyberStorm MK2) clocked at 50 Mhz. What risk would I be running? I guess the 68060 wouldn't overheat, but what about the power supply?
As others have said, the fan cools the entire machine, accelerator and zorro cards. do not remove it or everything will overheat-The psu may die first.. I have been using Noctua NF-R8 fluid bearing fans in them and find they give a cfm increase as well as being much quieter than the original. Its also not a good idea to slow the fan with resistors,as cfm decreases exponentially with speed i believe.
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Back when they came out, that was a big problem for people in some regions. I remember usenet posts from people in Australia that could not use their new A4000D's in the summer! If you are in Norway, could be a different situation. I know Sweden had to retrofit the coastal patrol submarines they exported to middle eastern countries to add air conditioning - they had never even thought about AC when using them off Sweden, they needed heating.
The stock A4000D ps CBM bought is junk, although many are still running. LoadWB is right - the only limitation is form factor, there is only so much room inside the case. I mounted my replacement -behind- the case, behind where the ps normally goes, and used a cantilever system to support it. This consists of, on top, two steel bolts with curved hooks on one end to catch the back of the ps, and the threads and nuts on the other tensioning (is that a word?) it unto the case. The ps fan still draws air through the case, and now I can use just about any supply I can find. I should post a picture.
Years ago, when I had too much time on my hands, I made my A4000D totally silent. I got a bunch of surplus Linear DC power supplies, one for each needed voltage, probably from old minicomputers. Each one was half as big as my A4000D, and twice (or more) as heavy, and I needed three (+5V, +12V, -12V). Put them on a shelf below and used automotive starter cable (big as your finger or thumb) to get the power to the motherboard. These supplies had big fins for passive cooling , no moving parts! Left the case off the Amy :) Was wonderful, but when time came to move, I could not take the beast of a setup :( Went back to ATX setup described above.
The stock 4k psu's are not junk, as a matter of fact they have the exact same switching topology as modern psu's and of AT ones of the day. I do prefer the skynets to the liteon versions(easier to recap at least) however, both work exactly the same way as any switching psu.The fast that most of these psu's made it 15-20 years is pretty amazing. If you want to see junk go thru most of todays atx,itx etc. very poor caps, little to no filtering,high ripple and poor +5 regulation. this is so common now its not funny, even some of the so called name brand 80+ certified atx psu's bomb. put a high quality fan with more cfm than the stock one and most all problems go away.
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Hi,
Just a thought. I like silent computing and my Amiga 4000 has a power supply fan blowing air the wrong way. It's a known problem that quite a few A4000s are constructed this way, the fan is blowing hot air into the power supply and not out of the chassis.
Now, my questione is this: is it a very bad idea to just remove the fan completly? This A4000 is quite cold, the CPU is a 68060 (CyberStorm MK2) clocked at 50 Mhz. What risk would I be running? I guess the 68060 wouldn't overheat, but what about the power supply?
Just a quick note.. Get a quiet fan and have it point out of the chassis! The fan should not blow it's hot air on the cards or anything else.
The fan should draw thru the front and distribute around the cards cooling them and add the PS heat before exit...
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Not my pictures, but I was always a fan of A4000 PSU mods like these:
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Just a quick note.. Get a quiet fan and have it point out of the chassis! The fan should not blow it's hot air on the cards or anything else.
The fan should draw thru the front and distribute around the cards cooling them and add the PS heat before exit...
very true! I was surprised to see it was pushing hot air into the system when I recently took mine apart to change the caps...was good that I did as few caps already started leaking slightly. Anyhow great time to also change the fan with a more modern quiet fan and more importantly facing in the right direction lol:hammer:
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Just a quick note.. Get a quiet fan and have it point out of the chassis! The fan should not blow it's hot air on the cards or anything else.
The fan should draw thru the front and distribute around the cards cooling them and add the PS heat before exit...
If you look at the 4000 case design, it does not pull any air through the front,it can't because for the most part the front bezel seals it all off(well not perfectly,but pretty well)..
Air enters the back of the case through the holes near the slot brackets,moves over the cards towards the front, goes around the zorro slot board at the front, and over the accelerator and into the psu and out the back of it. A little if pulled over the HD's but its almost a dead spot for air where the HD's are.
Some people add slot fans between zorro boards but it can actually fight the psu fan and make cooling worse.
One way to improve cooling is use the slot covers that are perforated with holes.It gives more area for air to come in. This works if your slots are not all full of cards.
The Noctua nf-r8 fluid bearing fan i mentioned earlier gains 5 more cfm than the stock amiga fan and is very quiet. They seem to last forever when kept clean.
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Thanks for the great explanation.
I never put time into my 4000d really and that info helped. I need to find a smaller cd rom cause I really don't know how any air gets moved in the system.
I assume that fan you recommended works in a 3000d power supply also?
If you look at the 4000 case design, it does not pull any air through the front,it can't because for the most part the front bezel seals it all off(well not perfectly,but pretty well)..
Air enters the back of the case through the holes near the slot brackets,moves over the cards towards the front, goes around the zorro slot board at the front, and over the accelerator and into the psu and out the back of it. A little if pulled over the HD's but its almost a dead spot for air where the HD's are.
Some people add slot fans between zorro boards but it can actually fight the psu fan and make cooling worse.
One way to improve cooling is use the slot covers that are perforated with holes.It gives more area for air to come in. This works if your slots are not all full of cards.
The Noctua nf-r8 fluid bearing fan i mentioned earlier gains 5 more cfm than the stock amiga fan and is very quiet. They seem to last forever when kept clean.
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@ mechy
waiting for a Noctua NF-R8 Redux-1800 to arrive as many of my friends said it was silent as heck with great air movement
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Thanks for the great explanation.
I never put time into my 4000d really and that info helped. I need to find a smaller cd rom cause I really don't know how any air gets moved in the system.
I assume that fan you recommended works in a 3000d power supply also?
I think the 3000 uses the same one as the 4000 but be sure to measure it, I dont have a 3000 psu in handy to check.
As for cdroms that are short, the SONY drives like crx320E(dvdrom+cdrw) ,crx230 series(cdrw),and crx230A work well..
ebay example: http://www.ebay.com/itm/Sony-CRX230A-CDRW-Internal-IDE-Drive-TESTED-/262365859076?hash=item3d16394d04:g:pasAAOSwJb9WrmPq
or black drives if the color makes no difference: http://www.ebay.com/itm/DELL-NP873-IDE-48X-CDROM-GENUINE-PRECISION-WS690-OPTIPLEX-320-PHILIPS-DH-48N1P-/251188734686?hash=item3a7c03eade:m:mXuv-PpS_8lsr-ThfvrggUA
longer drives also work but a right angle power plug will make life easier. i have found these long drives really dont hinder cooling too much in basic systems with a few cards.. obviously if its a toaster system with hot drives its not ideal.
Beware not all DVD/CDRW combo drives seem to work on amiga, but the sony's listed above worked for me.
This cable might give you perfect clearance on the long drive and keep the power connector from hitting the psu. I have used these alot when only long cdroms were available.
http://cdn.opentip.com/Electronics/Monoprice-Molex-Molex-p-1515249.html?gclid=CMjcrKzA8csCFQoNaQodHUQHqw
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@Mechy
Thanks for the suggestions.
I'm using a SCSI cdrom off the warp engine, never been a fan of ide. Any suggestions for a SCSI model?
This box has a warp engine 040@40MHz, a cv64/3d, ariandne nic, and melody z2. It uses one of those scsi2sd cards for the hd. Would you even bother with the smaller cd?
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I checked the Noctua R8/A8 specs, their airflow at max RPM is a ~50 m3/h.
According to data I have, the stock A4000 PSU airflow is ~70 m3/h.
Can anyone please verify ?
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@Mechy
Thanks for the suggestions.
I'm using a SCSI cdrom off the warp engine, never been a fan of ide. Any suggestions for a SCSI model?
This box has a warp engine 040@40MHz, a cv64/3d, ariandne nic, and melody z2. It uses one of those scsi2sd cards for the hd. Would you even bother with the smaller cd?
Scsi on the accelerator is always the best way. Unfortunately i cant recall any really short scsi optical drives. i have used pioneer dr-966's alot and they work well but are long. Some nec's and sonys also,but they are all pretty much full length. Some plextors are crazy long. The old apple optical drives work well also.
from memory some toshibas had problems ripping music right but thats prob. not a issue these days.
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I checked the Noctua R8/A8 specs, their airflow at max RPM is a ~50 m3/h.
According to data I have, the stock A4000 PSU airflow is ~70 m3/h.
Can anyone please verify ?
the information i find for the original 4k psu fan is as follows:
Matsu%&$#?@!%&$#?@!%&$#?@!%&$#?@!a Panaflo FBM-08A12M, 80cm x 80cm x 25 mm, 12 Vdc (brushless), 23 CFM
the Noctua at 50 m3/h = 29.428889 CFM
so the Noctua is roughly 5-6 cfm better.
Not sure who is right here, but i can tell you from experience in the many 4000's i own with many cards,the noctua fans make a difference and the case stays cooler.
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a) Do you need to solder to change the fan in an A4000D?
b) Is there a list of fan size and airflow for A1000/A3000/A4000D?
The noise of my 4000 is beginning to annoy me. (Nothing compared to my old 2000 though. Even after a cheap resistor mod it sounded like it was preparing for take-off.)
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a) iirc, yes, but you could solder a connector to PCB, so that future replacements are easy
b) I think its standard 8cm in A4000.
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Would there be space to snake back in something like one of these? http://www.ebay.com/itm/122103383578
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A fair bit of the fan noise comes from restrictions in airflow caused by the fan cutouts and louvres in the power supply. Cut them away and replace with wire guards which provide less air resistance. This will reduce noise as well as improve air flow. There are also new style fans that have quieter bearings and fan blades too.
http://members.iinet.net.au/~davem2/overclock/coola4k.html
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Well, I have a https://www.quietpc.com/nf-a8-flx incoming so I'm looking for the best and/or easiest ways to swap out the old. The current fan is so much noisier than this pc it's not funny. (Which is _nothing_ compared to what my 2000 was like - even after having a "NoiseKiller" heatbased resistor that made it a lot more silent...)
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All things considered, I would rather have a little noise, than burn up my Amiga. With fan technology today, it shouldn't be hard to keep your Amiga cool, without a screaming fan.
Back when I had an A4000, I used one fan, similar to this:
https://www.newegg.com/Product/Product.aspx?Item=9SIA68V46Y1204&ignorebbr=1&nm_mc=KNC-GoogleMKP-PC&cm_mmc=KNC-GoogleMKP-PC-_-pla-_-Case+Fans-_-9SIA68V46Y1204&gclid=EAIaIQobChMI3pX_6rT11gIVUwaGCh1DdgJQEAQYBSABEgIQcvD_BwE&gclsrc=aw.ds
and never had a problem - or much noise.
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I ended up just cutting the wires to the old fan near the pcb and squeeze the cable together with the other cables coming out of the PSU, and using a supplied 3-pin to molex converter to power it.
That was much smoother and less painfull than expected!
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Well, I have a https://www.quietpc.com/nf-a8-flx incoming so I'm looking for the best and/or easiest ways to swap out the old. The current fan is so much noisier than this pc it's not funny. (Which is _nothing_ compared to what my 2000 was like - even after having a "NoiseKiller" heatbased resistor that made it a lot more silent...)
cant go wrong with the Noctua NF fans, top quality and air flow is great in my full A4000
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cant go wrong with the Noctua NF fans, top quality and air flow is great in my full A4000
Should get one the right size for my 2000. Probably make a big difference.