BQE PSU fan swap

frootip · Post by **frootip** » Wed Jun 02, 2004 2:39 pm

I just finished installing cnps7000 and the zm80 and I've got to say this PSU is getting on my nerves... before, when people where complaining about it I couldn't understand it but now, now, oh and the fan on cnps7000 clicks @5v a little annoying but for now it's not a problem thanks to the PSU.

Ok then, I don't have the money to buy a new PSU plus where I leave getting a silent PSU's would be a major problem.. So I'm thinking about changing the fan, I remeber people were having problems firstly because the place for the fan is a little tight and I would need to push the L1A in and secondly because L1A is probably ain't gonna cut it. So, I'm thinking, and it hit me I have a ZM-OP1 laying around unemployed, it's thin, should be fairly quiet and has a better airflow than a Panaflo. Now the major question is, would it be better, is it quieter than the stock fan?

Are there any specs somewhere on the fan inside the PSU (dba, cfm etc.)?

Thanks.

MonsterMac · Post by **MonsterMac** » Wed Jun 02, 2004 3:09 pm

im not sure a zalman would be any better, a panaflo 80mm L1A @ 5V is prolly your best option, just make a psu duct so it will be cooled properly.

kloppe · Post by **kloppe** » Thu Jun 03, 2004 9:48 am

The SL350S fan is rated for 41CFM at 34dBA, so the Zalman without the inline resistor would just be pushing less air with just as much noise (36.5 CFM at 34.2 dBA).
An L1A @ 5V would probably be a good choise with a PSU duct, but if you don't have one the PSU'll most likely get waay to hot with such low airflow. I'm using a fan rated for 32.4 CFM at "<25 dBA" (whatever that means) running at 7V without a duct and with a case temp of around 26C, and it gets plenty hot already. I wouldn't dare to try anything with lower airflow in it without some way of feeding it cooler air.

frootip · Post by **frootip** » Thu Jun 03, 2004 11:22 am

Thanks kloppe exactly the info I needed, btw where did you dig that up? So I'm thinking of putting an L1A without a resistor, being rated 24cfm @~21dba it should be a good compromise of silence and cooling. Is it posible to mod the PSU in such a way that I won't damage anything in an irreversible way (no wire cutting, no plastic ripping etc.)?

Thanks.

kloppe · Post by **kloppe** » Fri Jun 04, 2004 2:12 am

frootip wrote:Thanks kloppe exactly the info I needed, btw where did you dig that up?

I Googled on the model number of the fan (it's a Top Motor DF1208SH btw).

So I'm thinking of putting an L1A without a resistor, being rated 24cfm @~21dba it should be a good compromise of silence and cooling.

I recall people recommending undervolted M1A's instead of a L1A @ 12V, but I don't really know which is better for decent airflow; someone with more experience of the Panaflo's will have to tell you that.

Is it posible to mod the PSU in such a way that I won't damage anything in an irreversible way (no wire cutting, no plastic ripping etc.)?

Sure, the old fan uses a 2pin connector and is easily removed. For the replacement you can just use a motherboard fan connector (which is what I did) or try to remove the 2pin connector from the old fan and use that if you want to use the voltage control; the fan header in the PSU is IIRC in a very awkward place though, so reusing that might be more trouble than it's worth.

Thanks.

Np.

hydroxyhydride · Post by **hydroxyhydride** » Fri Jun 04, 2004 7:09 pm

I'm using an L1A in my BQE power supply. Not too much trouble to switch. It was a little tight but as I have posted before it can be done with a little coaxing. (Bend, hit, etc).

As for an L vs an M series fan? I think it comes down to personal choice. Do whatever makes you sleep soundly at night (either confidence or silence). My box is an A64 that is always folding. The fan has been swapped for over a month now and my voltages are all fine.

The panaflo is currently @ 7V on a fan controller because I've been too lazy to open the case again and hook it up "properly" to the internal power connection.

Of course, I can't in good conscience recommend that you use an L1A in the power supply and control it manually

It isn't exactly a great idea but I'm just letting you know that if you decide to try, your power supply won't explode ....at least not immediately.

frootip · Post by **frootip** » Sat Jun 05, 2004 12:50 am

Thank you all for the tips, I've modded my PSU with an L1A, I currently hooked it up through fanmate due to the fact that I need to find a 2 pin connector to hook it properly inside the PSU. Anyhow running it @7v was not for me, the exaust air was too hot when running prime95 so it's going @10v now.

EDIT: Has anyone hooked their L1A to the 2 pin connector inside the PSU? I'm asking because the original fan is rated 0.2A @12v while L1A is only 0.068A so if the voltage variation in PSU is current related that would mean there won't be much help plugging the L1A, since the PSU would prolly rump it up to 12v pretty fast.

markjia · Post by **markjia** » Sun Jun 06, 2004 9:17 pm

I'm also thinking about replacing the fan in the SL350S with a L1A. Except i will not be using it in the BQE...instead, i will be using it to power an old PowerMac 6100. The machine's PSU died, and i am currently using an old AT psu externally to power the machine. But as you would probably guess, the thing is not that quiet. So, as i will have an extra SL350S (i'm replacing it with a NX3000 in the BQE), i will be using it in place of the AT psu.

The 6100 is really stripped down. Aside from it's motherboard/60MHz CPU (yes, no typo...60MHz

), the only other device connected is 2x CD-Rom. The original PSU is only 86W (and it powered a HD as well).

...I think i'm starting to blab...I'll get to my real questions...

Can I connect the L1A internally in the PSU? Looking at the photos here: http://www.cloudworld.net/diary/index.p ... 2004-06-06, it seems that the stock fan has three pins (as there are three wires). So, does this mean that the fan is temperature controlled? And if so, can't the Panaflo simply be connected in its place? Why is it necessary to use a Fanmate?. Also, I don't think that the MB has a three pin fan connector (at least not one that is easily accessible), so it is a bit more more troublesome not to use the PSU's internal fan connector.

Given that the psu will be powering less than 86W max, there should be no real for the fan to speed up (unless of course the L1A is that weak), and there would be no need for a seperate fan control (assuming the PSU does not reduce its output to 5V).

Longbow · Post by **Longbow** » Mon Jun 07, 2004 6:20 am

markjia wrote:Can I connect the L1A internally in the PSU? Looking at the photos here: http://www.cloudworld.net/diary/index.p ... 2004-06-06, it seems that the stock fan has three pins (as there are three wires). So, does this mean that the fan is temperature controlled? And if so, can't the Panaflo simply be connected in its place? Why is it necessary to use a Fanmate?. Also, I don't think that the MB has a three pin fan connector (at least not one that is easily accessible), so it is a bit more more troublesome not to use the PSU's internal fan connector.

the stock fan in SL35S has 3 wires, but ony two of them made to the internal power connector, namely live and ground, then the ground and rpm monitor made to the outside of psu, and can be connected to a 3pin fan supply on the mb, to monitor the rpm.

the panaflo can be connected inside the psu, with some painful-pin working, but panaflo at 12V does make some noise.

markjia · Post by **markjia** » Mon Jun 07, 2004 11:36 am

Thanks for the info. I am 99% sure that there is no temperature control on the MB, and not even sure if there is a fan connector (and even if there was, i doubt it would be close enough to be of use). Seems like I will have to wire the connector myself (maybe split it off of one of the peripheral connectors).

markjia · Post by **markjia** » Mon Jun 07, 2004 11:43 am

On the other hand...is it possible that the PSU supplies 5V by default? In which case, i would not need to wire the L1A manually to 5V leads. Or it is that the voltage is controlled by the fan itself?

chylld · Post by **chylld** » Mon Jun 07, 2004 12:03 pm

i've done the L1A mod on my bqe and it runs fine @7v. any faster and it's unacceptably loud.

bend the grill slats parallel to airflow and remove the fan grill, this did wonders for me. i've been running this psu like this for half a year now with no problems