Much gain from replacing SonataPSU fan?

qualia · Post by **qualia** » Mon Mar 14, 2005 3:54 am

With Panablo? In the experience of those who have this experience, is it worth voiding a warranty?

... still questing for more silence

GrahamGarside · Post by **GrahamGarside** » Mon Mar 14, 2005 5:36 am

ultimately to make this unit quiet the fan has to be replaced. theres just no way of getting it to spin slow enough to be quiet, even with cool air. I managed to get it down to 1300rpm but it was still audible. Just swapping it without making sure it has good air flow also won't do much to keep it quiet.
I have swapped the fan for a sleeve bearing unit which spins at around 1000rpm and isn't audible over my hard drives. With a tidy case the heatsink temps in the psu don't go over 55°C so I figure this is acceptable.

If you leave the fan on the psu's fan line then you need a fan which will be quiet on ~10V as during load theres just no way to stop it reaching this unless your drive bays are empty and you can duct cool air to it.

The question that I would ask rather than 'is it worth voiding the warranty?' is is the warranty worth keeping?

Tibors · Post by **Tibors** » Mon Mar 14, 2005 12:10 pm

I have done several mods to improve the airflow through my Sonata. I have replaced the fan inside the PSU with a Nexus fan on the outside of the PSU. This system had a P4 3.0 Prescott, onboard video and one HD. The highest voltage the PSU fan got, running F@H and CPUburn, was 8.61V. This was with a room temp of 26.5°C.

A Nexus at 8.61V is a lot quieter than the stock fan.

qualia · Post by **qualia** » Mon Mar 14, 2005 11:03 pm

Supposing I'm willing to cast my warranty aside. Would it be okay to replace stock fan with Arctic Fan Pro TC from Recommended list (as it just happens I have one around), as it comes with a thermal sensor of its own and I'm not sure if I would not get some funny results connecting it to Sonata's PSU voltage-variable fan-line. I don't know stock amperage rating, either. Maybe it is there on the fan, but I did not get around to unscrewing PSU yet.

I was toying around and I connected Arctic to Zalman's fanmate, and at ~5V it wouldn't even start.

Devonavar · Post by **Devonavar** » Tue Mar 15, 2005 12:33 am

If you've already purchased the AC fan, I'd do a test before screwing it in permanently. The air coming out of the Sonata PSU is likely to be so warm that the thermal control of the AC fan will be useless. They're nice fans, but probably not ideal for use in a PSU.

That said ... test it! All we can do on the forums here are speculate. If you have the parts already, try it out and let us know!

GrahamGarside · Post by **GrahamGarside** » Tue Mar 15, 2005 3:45 am

As Devonavar said, the psu air gets so warm the fans thermal sensor probably wouldn't have any effect.
The stock fan doesn't have any rating on it, it's a nasty cheap bit of clear plastic tat that has no place in whats meant to be a quiet system.
It's worth mentioning that a simple change to a 1.4W sleeve bearing fan alone, still on the psu's fan line lowered the speed to 1200rpm from 1400rpm in my psu without huge impact to the temperature of the unit.

qualia · Post by **qualia** » Thu Mar 17, 2005 7:25 am

Actually I went ahead and bought a japanese version Panaflo L1BX, and installed it. Process did not go as smoothly as I'd wished, but ultimatelly my computer is back online. I don't have any advanced instrumentalia, but overall I'm satisfied with the results. Right now the noisest component is 120mm stock Antec @5V, so it's a diminishing returns game.

I guess I'll try to disconnect that sucker for now and see how temps react. Airflow and temps will suffer of course, but maybe just within safety limits. Will see.

GrahamGarside · Post by **GrahamGarside** » Thu Mar 17, 2005 8:40 am

Woh! don't disconnect the exhaust fan, you'll cook your components quicker than you can say damn that was a silly thing to do

Get a couple of zener diodes and solder them into the fans + line, this should bring the voltage down to 3V and the fan will be near enough silent

qualia · Post by **qualia** » Thu Mar 17, 2005 9:10 am

Any real-world bad experiences? I understand the theory, but I'll say this: I've dealth with some number of computers and I can assure you that many did not have any rear-exhuast-fan mounted and I did not hear about any of those systems going down.

Before I swapped fan on my PSU I did this myself (Sonata), just to check temp&sound differences and of course temps went up (about 10C), but system still seemed stable, CPU at ~65C (Barton@2Ghz).

GrahamGarside · Post by **GrahamGarside** » Thu Mar 17, 2005 9:59 am

If i disconnect my rear exhaust fan in my sonata, with an athlon64 3400+ newcastle, 6800 and 2 7200.7's it puts my cpu temp up about 5°C andabout the same for my hard drives. But the northbridge and pwm's get incredibally hot very quickly, normally the northbridge and pwm heatsinks are quite warm to touch, turning the fan off makes them painfully hot for even the briefest touch

qualia · Post by **qualia** » Thu Mar 17, 2005 4:16 pm

I did it a test and let it run under load (united devices agent) for a few hours.

Exhaust off / on
CPU: 57C / 47C
MB: 46C / 36C
HDD: 53C / 44C

I consider it a big difference, though I also consider those higher temps to be on the safe side (before I switched to Zalman 7000AlCu I was running some old Zalman 3000CNPS and CPU was at 61C+ with exhaust fan on). I noticed that with rear fan off PSU fan increased its rpm to compensate a bit. I think I might try resistor/diode on the 5V rear fan line.

GrahamGarside · Post by **GrahamGarside** » Fri Mar 18, 2005 8:10 am

For the MB temp add another 30 or so for the PWM's and that HDD temp is bordeline max, remember the sensors aren't the most accurate in the world

Elixer · Post by **Elixer** » Fri Mar 18, 2005 9:51 am

qualia wrote:Supposing I'm willing to cast my warranty aside. Would it be okay to replace stock fan with Arctic Fan Pro TC from Recommended list (as it just happens I have one around), as it comes with a thermal sensor of its own and I'm not sure if I would not get some funny results connecting it to Sonata's PSU voltage-variable fan-line. I don't know stock amperage rating, either. Maybe it is there on the fan, but I did not get around to unscrewing PSU yet.

I was toying around and I connected Arctic to Zalman's fanmate, and at ~5V it wouldn't even start.

I'm not sure it will even fit. The fan in the sonata psu is 25mm thick I believe. The AC TC fan is 30 or 35mm correct? If you do decide to use it and can get it to fit I think just plugging it straight into 12V might work because your psu heats up the thermal sensor in the fan should increase the speed to compensate.

GrahamGarside · Post by **GrahamGarside** » Fri Mar 18, 2005 10:37 am

Does anyone know if the true power 380's fan control is on the ground or + line? I know most other psu's have it on the ground allowing you to connect the + line up to 5V and have 5V as the most the fan will run at

qualia · Post by **qualia** » Fri Mar 18, 2005 10:50 am

Right now I have PSU all in one piece, so I can't check voltages for you.

I tried Zener diode on the rear fan, it brought voltage to 4V, but fan wouldn't start then. So back to 5V, and that's the level of silence I'm going to live with... until I get another idea.