Some useless fan swap test info

burcakb · Post by **burcakb** » Mon Jun 21, 2004 7:13 am

The following is just the results of some stupid testing I've done over the weekend. I don't know how it'll be useful but something tells me I have to post this.

Recently I did a fan swap on my Antec Sonata PSU with a 80mm Acoustifan. I attached the power, ground and tacho to appropriate leads, covered the connections with electrical tape, started stability testing and burned my mobo in the process. The dead mobo has an interesting property though. It can turn on the PSU and has one fan header operational, the northbridge also draws power but nothing else. So I can run a PSU and a fan header without a CPU or RAM. Interesting platform for testing.

I started and ran the PSU to see how the acoutifan performs in cooling the PSU. Since the power draw of the mobo is very very small, this could be considered an "idle state" test for the PSU. I measured the voltages on the fan-only molex connector to see how the PSU ramps up.

On cold boot, the fan does NOT operate. Remember, this is a thermally controlled acoustifan and for it to achieve full 12V status, the temp sensor has to record something around 70C on the heatsink it is wound around. Add to this the 5V (tested through the fan-only header) of the PSU controller, the fan just doesn't have enough juice to start. Now, there's a fanless PSU

The PSU upped the voltage all the way to 5.8V before the acoustifan kicked in. In about 15 minutes the setup stabilized at 5.34V. The exhaust air felt warm. As the mobo is dead, I couldn't monitor the rpm but I guess the fan was doing slightly less than 1000 rpm with absolutely no noise.

Ambients for above test was a high 28C. I turned on the A/C to drop ambients to 22C. The PSU stabilized at 5.10V. I almost expected the fan to stop working but it didn't.

I don't know how useful all this is but I had to get it out

wim · Post by **wim** » Mon Jun 21, 2004 9:15 am

burcakb wrote:The following is just the results of some stupid testing I've done over the weekend. I don't know how it'll be useful but something tells me I have to post this.
-snip-
The dead mobo has an interesting property though. It can turn on the PSU and has one fan header operational, the northbridge also draws power but nothing else. So I can run a PSU and a fan header without a CPU or RAM. Interesting platform for testing.
I started and ran the PSU to see how the acoutifan performs in cooling the PSU. Since the power draw of the mobo is very very small, this could be considered an "idle state" test for the PSU.
-snip-
I don't know how useful all this is but I had to get it out

not very useful... you can power on a psu without a mobo - i.e. run the psu in a real "idle state" - by shorting the green wire on the motherboard connector to ground. i use an alligator clip hooked between the mobo connector and the psu chassis. this is pretty much what the case power switch does, thru the mobo and through the green wire's pin. yes it's great for testing noise levels of fans.

btw save your motherboard's life next time and power on the psu using this method BEFORE you connect it up to the rest of the system!!

DanceMan · Post by **DanceMan** » Mon Jun 21, 2004 10:48 am

Are you sure the board is dead? Did you clear the CMOS? Also disconnect everything but the bare minimum: cpu, hsf, psu, keyboard, vid card, ram, power button, and see if it will boot. Try it once more after it's out of the case before you toss it, and preferably with a different cpu, an old PCI video card, and different ram.

burcakb · Post by **burcakb** » Mon Jun 21, 2004 12:02 pm

I know about the green wire but it's much easier to have a mobo header to plug/unplug things from. Plus, it let me measure voltages across a number of places.

I did test the leads for anomalities before connecting it to the mobo. It actually worked fine for about 10 minutes - actually until I started messing with it.

And yes the mobo is dead. The underside has the 12V copper line burned and peeled off the PCB. I guess the antistatic bag I had the mobo on wasn't as clean as I thought.

Ephemeral · Post by **Ephemeral** » Mon Jun 21, 2004 12:40 pm

Doh. Unless you "cleaned" off the conductive layer of the antistatic bag, it would not be clean enough. Not drying to rub salt or anything, just recommending not to use AS bags with "live" components in the future...

DanceMan · Post by **DanceMan** » Mon Jun 21, 2004 1:08 pm

Ephemeral wrote:Doh. Unless you "cleaned" off the conductive layer of the antistatic bag, it would not be clean enough. Not drying to rub salt or anything, just recommending not to use AS bags with "live" components in the future...

I've generally used a folded up newspaper. I'll remember not to use an anti-static bag. Thanks for the heads up.

burcakb · Post by **burcakb** » Mon Jun 21, 2004 11:54 pm

Ephemeral wrote:..... "cleaned" off the conductive layer of the antistatic bag...

errr...."conductive layer"???.....What conductive layer???.....You mean??....Oh.....I.....errr......uhuuu....my, my mobo.... uhuuu.

Thanks man, I was all setup to test my NEW mobo on a similar bag.

wim · Post by **wim** » Tue Jun 22, 2004 1:59 am

Ephemeral wrote:Doh. Unless you "cleaned" off the conductive layer of the antistatic bag, it would not be clean enough.

hehehe well said

burcakb wrote:I know about the green wire but it's much easier to have a mobo header to plug/unplug things from

a mobo fan header? is that any easier than using a little 4-pin molex / 3 pin fan header converter?

Some useless fan swap test info

Some useless fan swap test info

Re: Some useless fan swap test info