Changing Fan in ReadyNAS ultra 4+ PSU

Looking at photos of the backs of all the 4 bay units (Ultra 4/Ultra 4 Plus/Pro 4) none show a 40mm fan on the PSU. In fact, no Netgear 4 bay NAS that I am aware of since it was removed from the NV some 5 years ago (the Rev B of the NV had the fanless power supply). If your Ultra 4 Plus has a 40mm fan in the PSU area, that is certainly a new one on most of us. Can you provide a photo?

The Pro 6 has two fans on the back as well as a CPU fan, but the smaller one appears larger than 40mm.

The PSU is buried below the drives so you can't see the fan unless you take the unit apart.

I'll take some photos this weekend and post them.

Are you saying that the Ultra 4+ PSU is normally fanless? and the only fan in the whole unit is the 92mm on the back?

Cheers
Anthony

demusss wrote:
Are you saying that the Ultra 4+ PSU is normally fanless? and the only fan in the whole unit is the 92mm on the back?

Yes. Unless Netgear made a production change.

Keep in mind when changing fans you must make sure the CFMs are the same or better than Netgears OEM fan.

claykin wrote:
Yes. Unless Netgear made a production change. Keep in mind when changing fans you must make sure the CFMs are the same or better than Netgears OEM fan.

Then Netgear have made a production change then.

I've found details online about the fan but not the CFM. I'll post a link wth the pictures.

The case fan is mounted in a back panel that is about 3/4 of the back area. In order to remove the PSU, you would have to remove a screw that is under a sticker that warns that removal voids the warranty of the unit. DO NOT remove the PSU. You can actually see quite a bit without removing it. There should be a plastic shield in the PSU that prevents airflow from bypassing the metal shield over the components. The air flow must enter the case at the front and side vent holes and then enter the shield at the front, under the drives through vent holes in the shield pass over the components and exit the shield at the back to exit via the fan.



While the image above is the replacement for an NV/NV+, the PSU in all 4 bay units should be similar, unless, as demusss said they have made a change that has not been announced. At one time the original NV (Rev A) had a 40 mm fan that was plainly visible when looking at the rear of the unit, it was removed by a production change in 2006. The changed NV is referred to as (Rev B) and the PSU is similar to above without the plastic shield and metal cover over the components. That early PSU (I have one in my NV+) gave problems with early failures and the improved version is pictured above.

The 40mm fans are found in the rack mount units and run a very high speed and are notoriously noisy. One of the reasons rack mount units are normally found in their own room.

The fan on my NV+ is currently running at 2027RPM and both my NVX unit fans are running at 1956RPM. The temperature of my NV+ (3 x 1TB drives) is 90F, the primary NVX (sitting on top of hutch) with 2x3TB + 2x1TB drives is 113F and the temp of my backup NVX with the same drive configuration as my primary unit and sitting on top of a table next to my NV+ is 102F. I am sitting less than 5 feet away from them and only hear a low hum from the combined 3 NAS units and my desktop PC.

There have been comments in the past about some of the 4 bay units being noisy, and others with the same units saying they are quiet. I personally think the drives make more noise than the fan.

Here's some pics.

Hoping the links work ok couldnt figure out how to show the pics on here.

http://www.flickr.com/photos/anthony_s/6035377571/

http://www.flickr.com/photos/anthony_s/6035955924/

Anthony

Surprising! Why they went with a 120W PSU that requires a fan when the NVX has a 220W with no fan is surprising. Maybe the extra heat of the Atom CPU did not allow for enough cool air inside the box.

Maybe a Jedi can chime in.

When I opened the image my jaw dropped too. I figured that with only a 120W PSU (vs the 220 found in the NV+ and NVX) that it would not need one. As Spock used to say "Fascinating".

I looked at a few 40mm fans on Newegg, and realized that there could be several problems. First is the fact that unlike the 40mm fan originally in the NV (RevA) which was mounted in the back panel of the PSU panel, the fan in this PSU is integrated into the actual PSU itself. To use an old boiler context, the original NV PSU fan was an induced draft fan (pulls the air through) whereas the fan in the new system is a forced draft fan (pushes the air through).

Then you have to make sure the new fan pushes as much air as the original fan, and most 40mm fans are of a fixed speed.

To replace the fan, you obviously have to take the PSU housing apart. Of course, by removing the PSU, you are aware you have already voided the warranty. It would be nice if you were able to purchase a new PSU to play with, but that is not a part that is separately available.

Thinking about it, replacing the fan with another small one running at full pelt is probably also going to be noisy.

Has anyone used a standard ATX power supply on these? I know theres going to be some differences because the Ultra4 doesnt use negative voltages, but with a bit of rewiring it should be possible.

Might be easier to just hide it in a cupboard and let it whir away to itself.

btw the sticker on the back doesnt mention anything about voiding the warranty.

Anthony

There have been other comments in posts in the past that while a standard 20 pin ATX (or the 20 pin section of a 20+4) is plug compatible to the ReadyNAS, it is not electrically compatible, but can be made so by re-arranging the wiring.

The sticker on voiding the warrant would not be on the back, but on the side covering one of the screws holding the PSU frame in place. On all of mine it is on the right hand side as you face the front and visible only after removing the right hand side plate. Removing the side plates, top plate and back plane does not void the warranty, but removing the PSU in the past did. I have removed my NV+ PSU to blow the dust out, but then that warranty is long out of effect. I will not remove the PSUs in my two NVX units as they are still covered.