Any problem with soldering the ATX power connector wires?
 

I am working on a project that requires me to extend my ATX power connector's leads to get power from where I put the PSU into my system. Will I run into resistance issues if I just cut the wires near the end of the ATX power plug and then solder on new wires from an old PSU? Wires would be same gauge and all but I was wondering if the soldering joint would cause any issue.

My guess is "No way pH go for it!" but I figured I have a day or two until I need to do it so I might as well ask.

I did it once but a little different. I de-soldered a ATX connector off a dead mobo, cut the ATX connector with as much wire as available (about 9") off a dead ATX power supply and soldered the cut wires to the connector from the dead mobo to make an extension. That way I didn't have to butcher the wires of a perfectly good power supply. :D

I never seen any negative effect from that. All the rail voltages seemed to be were they should have been. :shrug:

I had to solder on a new ATX plug on my Enermax 431w P/S when the stock plug got fused to my old POS Epox mobo. This was back during the KT266a era. I bought an ATX extension cord (meaning the main 20 pin ATX cord) and just cut it in half and used the plug end. I staggered the solder connections as to not get one big mass of heat-shrink at one point.

I have been running the same Enermax with my heavily overclocked AMD system for years without problems. My current mobo is the NF7-S rev.2 BTW.

Some pics of the fused plug and working new plug...

Sweet, now I don't have to ask the same question in a couple of months time (was planning something along those line..)

Extending works better if you have a PSU that has remote sense lines for all the positive voltages (and you wire correctly to preserve than awesome function).

"Remote sense?" you say. Okay, maybe you didn't say that, but someone out there did. :) As part of the voltage regulation, PSUs monitor their voltage outputs and adjust as necessary. But with the larges currents running to the motherboard and the small wiring resistance, that voltages at the mobo don't exactly match the voltages inside the PSU.

Standard on ATX power supplies is a thinner wire attached to the +3.3 V lines. It doesn't carry power to the ATX connector, instead it allow the PSU to measure the voltage at the ATX connector. The PSU doesn't output 3.3 volts -- it output whatever is needed to give 3.3 at the connector.

Newer, better supplies have remote sense on +5 and +12 volts, too. If you have one of those, you can make your wires really long and still have the proper voltages at the mobo, though voltages on your hard drive and floppy connectors will be a bit higher than normal.

And, if you're really cool, those remote sense lines make for an easy way to tweak your supply voltages. :cool:

Usually, the main voltage drop through a wire will be at the connector (if it isn't, fix it!). So extending the cables should have a negligeable effect.

Otherwise the signal lines are TTL, so they'll be just fine.