Increasing load on 12v - NeoHe Help in setup with diagram

deeph · 12th July 2006, 8:20 PM

Hi, Im after some advice. I am still running a SocketA AMD1800+, with Zalman 7000 ALCu, 4 HDDs off the motherboard and 1 HDD off an ide controller card, 1 lan card, 32mb video, sound card. No CD, No FDD. Original power supply is a Aopen 250W with a Panaflo 80mm fan (which I replaced with the stock). Its basically a storage server.

I recently purchased an AntecNeo (despite all research - arhh), and when I connected it to the system it would not boot up. I then loaded up the system with as many devices as I could and the PSU was fine. So after re-reading the silentpcreview site, it seems as though others have had the exact same problems - Low power system not booting with high efficiency PSUs.

I refer you to this thread,
http://forums.silentpcreview.com/viewtopic.php?t=30289

In order to 'fix this problem' users have installed a resistor to boost up their 12v rails so that the is able PC to boot. Now I am just looking for some clarification. From the above thread, a Mod stated that a 25ohm 10W resistor would be sufficient, loaded onto a spare molex. Is such as resistor ok?

From what I have gathered, I have also drawn up a diagram. I am not sure, but I think that Option 1 is correct? Yellow 12v connected to ground black.

Cheers

Odje · 12th July 2006, 8:45 PM

first one, resistor between yellow and black (12-0=12). There is not voltage between two yellow wires (12-12=0).

EDIT: That 10W resistor is going to get farily hot and waste 10W of power. A switch would be a good idea. An automatic switch would be even better. Connect the resistor to the normally closed contacts of a relay. Energise the relay after a few second time delay from power up.

nux · 12th July 2006, 9:29 PM

Quote:

Originally Posted by Odje

That 10W resistor is going to get farily hot and waste 10W of power.

It wont waste 10W of power.

P=V^2 / R
P = 5.76W

That is pretty small in comparison to the rest of the computer, but still I agree with you on being able to switch it. I cant see how that small a load will make the PSU boot *shrug*

lagmaster · 12th July 2006, 9:36 PM

Every little bit helps.

dakiller · 12th July 2006, 10:08 PM

20W would be a nice load that should make it play a bit nicer

Get 2 or 3 18ohm 10W resistors and wire in parallel, they will give 8W of power load each - http://www.jaycar.com.au/productView.asp?ID=RR3355

Now they are going to get hot so have them placed in your case somewhere where they will get some airflow over them, just don’t worry too much on the temperature as even if they sit at 100C they will take it fine but with some airflow they will take it a lot better

Odje · 12th July 2006, 10:35 PM

Quote:

Originally Posted by nuxie1

It wont waste 10W of power.

P=V^2 / R
P = 5.76W

Ah yes, my bad

deeph · 13th July 2006, 2:04 PM

thanks for the advice. will drop by jaycar tomorrow and pick up 3x 18ohm 10 watt resistors. ill post back for an update on how the system goes.

12th July 2006, 8:20 PM	#1
deeph Member Join Date: Jan 2006 Posts: 3	Increasing load on 12v - NeoHe Help in setup with diagram Hi, Im after some advice. I am still running a SocketA AMD1800+, with Zalman 7000 ALCu, 4 HDDs off the motherboard and 1 HDD off an ide controller card, 1 lan card, 32mb video, sound card. No CD, No FDD. Original power supply is a Aopen 250W with a Panaflo 80mm fan (which I replaced with the stock). Its basically a storage server. I recently purchased an AntecNeo (despite all research - arhh), and when I connected it to the system it would not boot up. I then loaded up the system with as many devices as I could and the PSU was fine. So after re-reading the silentpcreview site, it seems as though others have had the exact same problems - Low power system not booting with high efficiency PSUs. I refer you to this thread, http://forums.silentpcreview.com/viewtopic.php?t=30289 In order to 'fix this problem' users have installed a resistor to boost up their 12v rails so that the is able PC to boot. Now I am just looking for some clarification. From the above thread, a Mod stated that a 25ohm 10W resistor would be sufficient, loaded onto a spare molex. Is such as resistor ok? From what I have gathered, I have also drawn up a diagram. I am not sure, but I think that Option 1 is correct? Yellow 12v connected to ground black. Cheers Last edited by deeph; 12th July 2006 at 8:22 PM.

12th July 2006, 8:45 PM	#2
Odje Member Join Date: Jun 2001 Location: Sydney Posts: 2,277	first one, resistor between yellow and black (12-0=12). There is not voltage between two yellow wires (12-12=0). EDIT: That 10W resistor is going to get farily hot and waste 10W of power. A switch would be a good idea. An automatic switch would be even better. Connect the resistor to the normally closed contacts of a relay. Energise the relay after a few second time delay from power up. __________________ FOR SALE: unRAID Server Pro Registration Key $75 There are only 2 reasons why you should run, 1. If you are being chased or 2. If you are on fire Last edited by Odje; 12th July 2006 at 8:52 PM.

12th July 2006, 9:36 PM	#4
lagmaster Member Join Date: Oct 2004 Posts: 3,063	Every little bit helps. __________________ My other PC is a kebab.

12th July 2006, 10:08 PM	#5
dakiller (Oscillating & Impeding) Join Date: Jun 2001 Location: SE Melb Posts: 6,156	20W would be a nice load that should make it play a bit nicer Get 2 or 3 18ohm 10W resistors and wire in parallel, they will give 8W of power load each - http://www.jaycar.com.au/productView.asp?ID=RR3355 Now they are going to get hot so have them placed in your case somewhere where they will get some airflow over them, just don’t worry too much on the temperature as even if they sit at 100C they will take it fine but with some airflow they will take it a lot better __________________ In memory of Cheers Z

13th July 2006, 2:04 PM	#7
deeph Member Join Date: Jan 2006 Posts: 3	thanks for the advice. will drop by jaycar tomorrow and pick up 3x 18ohm 10 watt resistors. ill post back for an update on how the system goes.