My new 24 port switch.

S

Silent Assasin

[H]ard|Gawd
Joined
Aug 1, 2004
Messages
1,120
Ok, so I just made the deal of the year for me. Last weak I won a used 24 port switch from Ebay for $30.20 shipped. I didn't find it untill about 10 minutes left on the auction so I didn't have much time to look it up untill after I won. It's a Netgear FS 524, 24 port switch.

But anyway, it finally arrived today and I plugged it in to test it out. First thing I noticed is how loud the fans in the back are.... There are two fans that are around 1.75" tall sitting in the back... Because of the size, they are really loud. I know that it's main intention was for a rack mount, but my main use will be just sitting ont he top shelf of my desk and it will also be used as my portible LAN switch. So after testing all of the ports, I opened up the casing to take a look inside. For a used switch, it was very clean inside. But anyway, the two fans are connected to 2 different 2-wire ports on the mainboard. Now I was wondering if it would be possible to take those two fans out and cut a whole inthe top to fit an 80mm fan with a steel gaurd. Or I might even be able to fit a 120mm fan up there. How hard would it be to wire a fan to work with the power supply? It would be nice if I could get a 120mm fan and run it at 7v, but I'm not sure how the 2-wire plugs work..... On the back, next to the power plug, the specs are 100-240 VAC, 50-60Hz, 0.75A max. There are no other power specs on the casing or the fan.

So would it be possible to run a regular 120mm fan at 7v on this thing?
 
weasel2htm said:
You would probably have to use a resistor to drop the 12V down to 7V
Click to expand...

I guess I could use a resistor if absolutely necesary....

Also, to the mods, I'm starting to think I made this in the wrong forum, possibly move it up to the Electronics?
 
Should be pretty easy to wire that up, but I wanted also to mention that a lot of rack mount switches have alarms that go off if any or all of the fans are disconnected. Make sure you test that out. I have seen some switches that even turn off if the fan is disconnected and wont fully power on till it is fixed. I guess to protect the switch from frying itself. Just a warning.

I have modified some Dell and Nortel switches with 120mm fans in them as well to lower the noise and it was quite easy to fit each time, lots of dead space typically. Good luck.
 
Mohonri said:
Pics! Pics! Pics! Pics! We want pics!

Click to expand...

Well they aren't the best of quality, but here they are.

Just a general front shot
DSCN0081.jpg


Just look at all those sexy ports.....
DSCN0082.jpg


Here it is fron the back side with the plug and the 2 fans.
DSCN0083.jpg


And here's the inside where the fans are plugged in.
DSCN0087.jpg


I can take more pics if you really wanna.
 
Other thing to consider which may fit in that back area would be a radial blower. Much less noise completely and might fit in that are if you can find an angled blower where the final duct is wider than the actual radial and motor. I will take a picture of what I mean when I get home. Many rack designs use radial blowers to deal with space constraints and noise at the same time.

Also, if you want the voltage rating off the line (short of a multimeter of course), taking one of the fans off the back will usually have a label on the back side showing what consumption the current fan already uses.
 
Mickey21 said:
Should be pretty easy to wire that up, but I wanted also to mention that a lot of rack mount switches have alarms that go off if any or all of the fans are disconnected. Make sure you test that out. I have seen some switches that even turn off if the fan is disconnected and wont fully power on till it is fixed. I guess to protect the switch from frying itself. Just a warning.

I have modified some Dell and Nortel switches with 120mm fans in them as well to lower the noise and it was quite easy to fit each time, lots of dead space typically. Good luck.
Click to expand...

Well I just tested that problem. It only works if at least one of the fans is plugged in.... If there is nothing plugged in, it won't even try to start up.

I also just did some test fitting with the fans. A 120mm is about 1cm too big to fit inside the case without thitting the top board... I can squeeze in 2x 80mm fans though if I'd like, but I think just 1 would be sufficient depending on how much power I can get to it.

Here's the guts.
DSCN0092.jpg


Clearance....
DSCN0093.jpg


And a test fit of an 80mm fan.
DSCN0094.jpg
 
Ok, so I just took out one of the fans as well. It's a Sunon N2K35. Says's it's DV5v - 1.0W.

If I can get my 80mm to run at 5v, that'd be pretty sweet as well. Just that I'm not to sure as to how I should wire it, and if it will even run with that low of a current.
 
Im pretty sure you could get a coolermaster 80MM LED to fan to run at 5V... mine will (i havent checked with speedfan in a while... but i know i can run them at a realy low % of power... if they dont spin, try pushing em first :p
 
0mega said:
Im pretty sure you could get a coolermaster 80MM LED to fan to run at 5V... mine will (i havent checked with speedfan in a while... but i know i can run them at a realy low % of power... if they dont spin, try pushing em first :p
Click to expand...

Yeah, but how funny would that be at a lan? "Hang on, I gotta push-start my switch. It's a manual and the battery's low!!"

::edit::

Seriously, though, you could also check out what else you can find in a 5v fan. Here are a couple of 60's that push 17-19 cfm at around 30dB: http://www.excesssolutions.com/cgi-bin/category/12450


 
0mega said:
Im pretty sure you could get a coolermaster 80MM LED to fan to run at 5V... mine will (i havent checked with speedfan in a while... but i know i can run them at a realy low % of power... if they dont spin, try pushing em first :p
Click to expand...

Yeah, but you don't want a power outage to stop your fan and then fail to restart it while you're not around. You could overheat the switch (which is why it requires at least one fan to be running).

The problem with the 60 mm fans is that they are much poorer in the CFM per dB ratio than an 80mm fan. That was the original problem of too loud of fans. The 80mm could probably do an equal CFM at 10 dB less noise.
 
Fenris_Ulf said:
The problem with the 60 mm fans is that they are much poorer in the CFM per dB ratio than an 80mm fan. That was the original problem of too loud of fans. The 80mm could probably do an equal CFM at 10 dB less noise.
Click to expand...

Right. I did try doing a quick search for the part number he listed on that sunon to try to get some idea as to the noise profile on it, but I couldn't find anything. Also, in terms of size contraints, there are also some thin fans out there. Didn't see any 120's though.

 
Some thin fans might work better. A standard 80mm fan clears the capaciters by just a couple milimeters. Even if I could find a thin 120mm fan, I doubt it would work. The mainboard to the switch is 2 layers. The top layer is about 1/2 an inch from the top cover....

Also, about possibly having to jumpstart the fan, that'd be a bad idea.... Most of the lans I attend are just at friends houses, so we have a tendancy to blow the circuit several times a night. If I forget to reset the fan in the middle, I'm sure the switch would still run because there would still be current running through the fan, just not enough to start it.
 
I wouldnt worry about not using a 120mm, that 80mm will move mouch more air than the tiny fans it started with comined. As for the 5V fan sensor, I dealt with that too by modifying some LED's into the chassis (lighted switch and no loud small fans - nice). I guess the draw on the power is enough to fool it in my case, worth a check if you have some LED's or small Cold Cathodes laying around. As for the 80mm fan and 12v line, the power supply in my switches had much like a computer power supply. It had both 12v and 5v lines. I just found the 12v line and spliced into it for the fan. In the pictures you have coming off your power supply a bunch of yellow wires, I would start with a multimeter and find the 12v line in there. It probably has a similar design to all the switches I have worked with. I doubt the switch's board only runs on 5V.... Hope that helps...
 
Mickey21 said:
I wouldnt worry about not using a 120mm, that 80mm will move mouch more air than the tiny fans it started with comined. As for the 5V fan sensor, I dealt with that too by modifying some LED's into the chassis (lighted switch and no loud small fans - nice). I guess the draw on the power is enough to fool it in my case, worth a check if you have some LED's or small Cold Cathodes laying around. As for the 80mm fan and 12v line, the power supply in my switches had much like a computer power supply. It had both 12v and 5v lines. I just found the 12v line and spliced into it for the fan. In the pictures you have coming off your power supply a bunch of yellow wires, I would start with a multimeter and find the 12v line in there. It probably has a similar design to all the switches I have worked with. I doubt the switch's board only runs on 5V.... Hope that helps...
Click to expand...

I could find the 12v line, but that wouldn't help with the problem of turning on. If there isn't anything plugged into the port, it won't turn on... Perhaps I'm overlooking this whole thing though. My 80mm LED fan that I have, it has 2 wires coming off of it, a ground(Black) and a 12v(yellow). Would I just be able t plug the yellow 12v line into the red 5v and be good with it? Or will I still need to put in a couple of resistors?
 
If I were you, I'd find a couple of fans that fit and are made for 12v. (50mm or whatever size you need). Small fans usually start with 5v in my experience, but a 12v 120mm usually won't. If you can find one that doesn't waste so much space near the motor and cut out those ridicuously inefficient grills this would actually cool better and be quieter.

TMD fans-tip magnetic driven. I haven't used them, but they have more blade and less hub due to different method of making 'em spin.

Otherwise, if you're not into the whole cosmetics thing, you could always external mount the 80mm's.
 
BoySetsFire said:
fuck it dude. build a new plexi shell for it instead!
Click to expand...
That would be rather cool. :p

If I were you. I'd rig it to a side panel on my case. Then discreetly attach an 80mm fan to the side via a dremeled hole. :cool:
 
Well, it's not the matter of modding it to fit anything. That's why I said this thread was placed in the wrong forum.... It should go up in th Electronics subforum.

I need to figure out a way of getting a 12v fan to run on a 5v power source. And remember, there has to be something plugged into the source, or else the switch simply won't run.
 
I have one of those switches somewhere... and i agree Loud as heck! what you want to do is cut a whole in the top of the case and install a slim 80mm fan. I have a slim 80mm Panaflo installed in mine.. works great the few times i used the switch. i would take pics but have no clue as to which box its located in. have 4 swtiches.. my dells rock! quiet and huge! good luck...
 
Here's my suggestion: if the switch won't work without a working fan, bridge each fan connector with a simple resistor that will draw the same current as the fan would if it were plugged in and running. Then you're free to plug an 80mm or 120mm fan into 12V, or use a regulator to drop the 12V down to something smaller, or whatever.

 
Mohonri said:
Here's my suggestion: if the switch won't work without a working fan, bridge each fan connector with a simple resistor that will draw the same current as the fan would if it were plugged in and running. Then you're free to plug an 80mm or 120mm fan into 12V, or use a regulator to drop the 12V down to something smaller, or whatever.

Click to expand...

Good idea, I didn't even think about that, but it just might work.

But before I start hacking at wires, I'm gunna try to see if I can get my slim fanto run at 5v. I just ordered 2 slim 80mm fans, should be here some time next week.
 
Silent Assasin said:
Well, it's not the matter of modding it to fit anything. That's why I said this thread was placed in the wrong forum.... It should go up in th Electronics subforum.

I need to figure out a way of getting a 12v fan to run on a 5v power source. And remember, there has to be something plugged into the source, or else the switch simply won't run.
Click to expand...
There are a number of 12v fans that will spin up with 5v. Some companies list the minimum startup voltage in the specs. Fans from old AXP/P3 heatsinks should both fit and work effectively.
 
That is why I put LED's on the fan outputs on the board. It used enough voltage for the board to accept that a fan was attached. I then spliced into the 12v line and ran the 120mm fan off that. There are 80mm fans that run off 12v, so just use those. Easy...
 
You must log in or register to reply here.
Back
Top