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Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems. |
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#1
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computer power supply
I tested the power supplies at work and found some had the -5v line not
working. Ive put these into systems and cant notice any difference between the ones with the -5v and the ones without. What is the -5v used for? |
#2
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computer power supply
Sleepy-Tom wrote: I tested the power supplies at work and found some had the -5v line not working. Ive put these into systems and cant notice any difference between the ones with the -5v and the ones without. What is the -5v used for? Most systems don't use it anymore. If it is used, it will be in an analog circuit, like the sound card. It was used for some of the early memory in the PC & XT, and has been carried over for 'Backward Compatibility'. -- http://improve-usenet.org/index.html aioe.org, Goggle Groups, and Web TV users must request to be white listed, or I will not see your messages. If you have broadband, your ISP may have a NNTP news server included in your account: http://www.usenettools.net/ISP.htm There are two kinds of people on this earth: The crazy, and the insane. The first sign of insanity is denying that you're crazy. |
#3
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computer power supply
"Sleepy-Tom" wrote in message u... I tested the power supplies at work and found some had the -5v line not working. Ive put these into systems and cant notice any difference between the ones with the -5v and the ones without. What is the -5v used for? RS232 communications, for one. |
#4
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computer power supply
On Sun, 14 Sep 2008 17:07:02 -0400, "Charles"
put finger to keyboard and composed: "Sleepy-Tom" wrote in message . au... I tested the power supplies at work and found some had the -5v line not working. Ive put these into systems and cant notice any difference between the ones with the -5v and the ones without. What is the -5v used for? RS232 communications, for one. That requires +/-12V. Some RS232 chips can generate both rails from the +5V supply via their internal charge pumps. - Franc Zabkar -- Please remove one 'i' from my address when replying by email. |
#5
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computer power supply
On Sun, 14 Sep 2008 01:08:57 +1000, Sleepy-Tom
put finger to keyboard and composed: I tested the power supplies at work and found some had the -5v line not working. Ive put these into systems and cant notice any difference between the ones with the -5v and the ones without. What is the -5v used for? The PCI bus does not use -5V: http://pinouts.ru/Slots/PCI_pinout.shtml I believe the -5V rail could have been used by ISA data acquisition cards. Some early DRAMs and EPROMs also required it. http://pinouts.ru/Slots/ISA_pinout.shtml - Franc Zabkar -- Please remove one 'i' from my address when replying by email. |
#6
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computer power supply
"Michael A. Terrell" wrote in message m... Most systems don't use it anymore. If it is used, it will be in an analog circuit, like the sound card. It was used for some of the early memory in the PC & XT, and has been carried over for 'Backward Compatibility'. Ah, you're full of ****. |
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