-5v Rail questions

kai · 12-31-2002, 12:02 PM

To continue on this thread http://forums.procooling.com/vbb/sho...&threadid=5307

Im still looking for an answer to the -5v question i did test it and it worked , in the bios said there was no -5v which there wont be cause its not hooked up , i didnt find any -5v on the psu i modded.
Whats the -5v used for?

jtroutma · 12-31-2002, 07:24 PM

The -5V rail is a direct path for the 5V rail to ground. Otherwise you are using the computer case as the ground. Not the best situation for computer equipment. If you are truely desperate, you could try using the black 5V rail off one of the HDD connectors comming from the PSU.

But be careful! I have never tried this myself and it MIGHT cause something nasty to happen...........like maybe a fire :shrug:

Brad · 01-01-2003, 04:23 AM

the -5v line is not used any more, it used to be used in the isa days for certain isa cards. as a matter of fact -5v isn't even part of the sfx spec, and will soon be dropped from atx as well.

-5v isn't "a direct path from 5v to ground" it is a line that is simply 5v less than ground.

Also there is no way you could use a line off you power connector, they are +12v, ground, ground, +5v. Not -5v.

Lastly, the 5v cable is red, not black

kai · 01-01-2003, 01:22 PM

sweeet so its not needed i can start the soldering and install it

kai · 01-01-2003, 01:24 PM

also i have another question pin 7 on the atxges power supply is +3.3V with an orange wire but there is a smaller brown wire also to the pin. any ideas?

Brad · 01-01-2003, 03:53 PM

the little brown one is a sense wire, that reads what the actual 3.3v line is at the end of the 3.3v wire. It will need to be connected, without it many psu's won't turn on, or the 3.3v line will end up at 5v

Butcher · 01-01-2003, 08:47 PM

Quote:

Originally posted by jtroutma
The -5V rail is a direct path for the 5V rail to ground. Otherwise you are using the computer case as the ground. Not the best situation for computer equipment. If you are truely desperate, you could try using the black 5V rail off one of the HDD connectors comming from the PSU.

But be careful! I have never tried this myself and it MIGHT cause something nasty to happen...........like maybe a fire :shrug:

No that's ground, -5v is -5V relative to ground...
All the black wires are ground (i.e. 0V), -5V is er *gets out meter* white

kai · 01-02-2003, 01:26 PM

yep i think i got it . i dont have any heatshrink , so i gotta get some but no $$ and no car so it might take a week lol.

Thanks for all the help sorry about the two threads. i did test it without the sense wire hooked up and it was fine but i will hook it up anyways. Im going to install a simple on off toggle switch for the power_good cause im not sure if its the same as power_ok.

12-31-2002, 12:02 PM	#1
kai Cooling Neophyte Join Date: Aug 2002 Location: blah Posts: 35	-5v Rail questions To continue on this thread http://forums.procooling.com/vbb/sho...&threadid=5307 Im still looking for an answer to the -5v question i did test it and it worked , in the bios said there was no -5v which there wont be cause its not hooked up , i didnt find any -5v on the psu i modded. Whats the -5v used for?

12-31-2002, 07:24 PM	#2
jtroutma Cooling Savant Join Date: Aug 2001 Location: SLO, CA Posts: 837	The -5V rail is a direct path for the 5V rail to ground. Otherwise you are using the computer case as the ground. Not the best situation for computer equipment. If you are truely desperate, you could try using the black 5V rail off one of the HDD connectors comming from the PSU. But be careful! I have never tried this myself and it MIGHT cause something nasty to happen...........like maybe a fire :shrug: __________________ Athlon64 X2 4200+ @ 2.5Ghz (250FSB x 10) OCZ VX 1GB 4000 @ 250FSB (6-2-2-2 timmings) DFI LANParty nForce4 Ultra-D SCSI Raid 5 x (3) Cheetah 15K HDDs LSI Express 500 (128MB cache) OCZ PowerStream 520W PSU ATI X850XT PE (Stock) DTEK WhiteWater + DTEK Custom Radiator Eheim 1250

01-01-2003, 04:23 AM	#3
Brad Thermophile Join Date: Oct 2001 Location: Nuu Zeeelin Posts: 3,175	the -5v line is not used any more, it used to be used in the isa days for certain isa cards. as a matter of fact -5v isn't even part of the sfx spec, and will soon be dropped from atx as well. -5v isn't "a direct path from 5v to ground" it is a line that is simply 5v less than ground. Also there is no way you could use a line off you power connector, they are +12v, ground, ground, +5v. Not -5v. Lastly, the 5v cable is red, not black __________________ 2x P3 1100's at 1400, Abit VP6, 2x Corsair 256mb PC150 sticks, 20gb 'cuda ATA-III, 2x 40gb 'cuda ATA-IV in raid 0. 20" Trinitron. No fans 2x 2400+ at 2288mhz (16.0 x 143), Iwill MPX2, 2x Kingmax PC-3200 256mb sticks, 4x 20gb 60gxp in Raid 5 on a Promise SX6000. Asus Ti4200 320/630. Cooled by Water

01-01-2003, 03:53 PM	#6
Brad Thermophile Join Date: Oct 2001 Location: Nuu Zeeelin Posts: 3,175	the little brown one is a sense wire, that reads what the actual 3.3v line is at the end of the 3.3v wire. It will need to be connected, without it many psu's won't turn on, or the 3.3v line will end up at 5v __________________ 2x P3 1100's at 1400, Abit VP6, 2x Corsair 256mb PC150 sticks, 20gb 'cuda ATA-III, 2x 40gb 'cuda ATA-IV in raid 0. 20" Trinitron. No fans 2x 2400+ at 2288mhz (16.0 x 143), Iwill MPX2, 2x Kingmax PC-3200 256mb sticks, 4x 20gb 60gxp in Raid 5 on a Promise SX6000. Asus Ti4200 320/630. Cooled by Water

01-01-2003, 01:22 PM	#4
kai Cooling Neophyte Join Date: Aug 2002 Location: blah Posts: 35	sweeet so its not needed i can start the soldering and install it

01-01-2003, 01:24 PM	#5
kai Cooling Neophyte Join Date: Aug 2002 Location: blah Posts: 35	also i have another question pin 7 on the atxges power supply is +3.3V with an orange wire but there is a smaller brown wire also to the pin. any ideas?

01-02-2003, 01:26 PM	#8
kai Cooling Neophyte Join Date: Aug 2002 Location: blah Posts: 35	yep i think i got it . i dont have any heatshrink , so i gotta get some but no $$ and no car so it might take a week lol. Thanks for all the help sorry about the two threads. i did test it without the sense wire hooked up and it was fine but i will hook it up anyways. Im going to install a simple on off toggle switch for the power_good cause im not sure if its the same as power_ok.

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