what's a QUALITY pwm splitter cable?

J

Jason

Limp Gawd
Joined
Feb 20, 2003
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490
so i wanted to run two slipstream pwms in a push/pull on my hyper 212+. i bought the fans and a gelid pwm splittler cable off of performance-pcs. the fans are just dandy, as expected, however the cable is a hunk of crap. one of the connectors was missing a pin straight out of the packaging!

i figure it'll be tough trying to somehow prove that i didn't break the pin off myself. so i don't think i'm going to waste my time with a replacement. plus (having not checked) i would imagine performance-pcs isn't going to rma a cable anyway.

so can anyone recommend me a QUALITY pwm splitter cable? right now i've resorted to using molex adapters on both fans and with both running at full speed my case sounds like a damn jet engine. :/
 
one other question.

if i take a fan with a 3-pin connector and run it into one of those 3-pin to 4-pin adapters and then connect the adapter into a 4-pin header on my mobo, will the fan work like a pwm? or do you have to have that 4th pin for the mobo to be able to adjust speed?
 
Jason said:
so i wanted to run two slipstream pwms in a push/pull on my hyper 212+. i bought the fans and a gelid pwm splittler cable off of performance-pcs. the fans are just dandy, as expected, however the cable is a hunk of crap. one of the connectors was missing a pin straight out of the packaging!

i figure it'll be tough trying to somehow prove that i didn't break the pin off myself. so i don't think i'm going to waste my time with a replacement. plus (having not checked) i would imagine performance-pcs isn't going to rma a cable anyway.

so can anyone recommend me a QUALITY pwm splitter cable? right now i've resorted to using molex adapters on both fans and with both running at full speed my case sounds like a damn jet engine. :/
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Let me guess. It's the pin on the very end. Its only missing on one of the fan connectors, not on the motherboard end. Am I right?

There is a reason the cable is missing a pin. IT IS DESIGNED THAT WAY. It is the RPM sense pin that is missing. PWM cables have 4 pins: 2 of which provides power (+ and -), 1 provides the PWM speed signal, 1 provides RPM sensing. The reason the pin is missing is simple, it is physically impossible to get RPM readings for 2 fans over one wire unless you overcomplicate it and add more circuitry (which no company wants to do). So since the voltages and the PWM signal remains the same and split between multiple fans, the RPM's are assumed to be the same between all of them.
 
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one of the connectors was missing a pin straight out of the packaging!
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It better have one pin missing otherwise it would not work. Both fans can not report their speeds at the same time over the same wire..
 
drescherjm said:
It better have one pin missing otherwise it would not work. Both fans can not report their speeds at the same time over the same wire..
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That's not entirely accurate Mr. President.

I had to consolidate two full three pin wires down to one and did so just by soldering them up matching color to color to get two fans from one three pin connection. It *kind* of works. The Kaze server sometimes gets confused and drops to zero on the RPM reading, but it's mostly stable. However, I did have to place the fan controller to silent as it was getting a little annoying with it beeping at random times. It would usually shut up after it warmed up. But two same speed RPM fans can work off of one connection.
 
It's much better and accurate to not to do that. Also there may be a slight chance of burning the speed sensor on one or both fans doing this.
 
When it comes to the accuracy, I'll certainly vouch for you on that one. You should see the numbers bop back and forth.

Thanks for letting me know about the speed sensor though. They're 80mm's on the back of the case and actually are not so necessary that I'd have to shut down the machine if they were to burn out. Maybe going further with the thread, how would one do this safely/better? Thanks again.
 
Do not connect the RPM sensor wire on both fans. Just pick 1 and use that. Cut the other wire.
 
So it's not necessary to have the RPM pin connected? I did try cutting a wire. Both fans stopped. I guess I cut the wrong one. There was red, blue, and black. I cut the blue wire, and they both stopped. :D
 
I suspect that's what happened. I think I cut it after the join which effectively cut both of them. It was a bit cramped and not well lit when I cut it.

I am going to replace them in any case because there are better and more silent fans out now. The case was bought about 4 or 5 years ago. I need a 120mm too. Thanks for the link. I'll be following that up when the fans arrive. Might be end of next week. Thanks!
 
Shotglass01 said:
So it's not necessary to have the RPM pin connected? I did try cutting a wire. Both fans stopped. I guess I cut the wrong one. There was red, blue, and black. I cut the blue wire, and they both stopped. :D
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Didn't you ever watch any of those spy movies as a kid?

You NEVER, EVER, NEVER cut the Blue wire!

Stuff blows up!

:eek:
 
if anyone needs me, i'll be in the corner with a huuuge dunce hat on. :D

it wasn't the pin on the end that was missing, though. it's the 3rd (or 2nd depending on which way you have the connector oriented) pin that's missing.

pin pin ___ pin

i already threw the cable in the trash, hah. luckily it's just sitting amongst a pile of papers and i'll be able to fish it out when i get home from work in the morning. i'll have to check to be sure the other connector has all four pins. the motherboard end of the cable did have four.
 
Jason said:
if anyone needs me, i'll be in the corner with a huuuge dunce hat on. :D

it wasn't the pin on the end that was missing, though. it's the 3rd (or 2nd depending on which way you have the connector oriented) pin that's missing.

pin pin ___ pin

i already threw the cable in the trash, hah. luckily it's just sitting amongst a pile of papers and i'll be able to fish it out when i get home from work in the morning. i'll have to check to be sure the other connector has all four pins. the motherboard end of the cable did have four.
Click to expand...

Yea, for a 3 pin the order is -|+|RPM. The fourth is for PWM control.
 
wait, so you're saying that the missing pin is in the proper location, correct?

- | + | missing rpm | pwm

sorry for the stupid question and to make you repeat yourself. i like to be 100% sure, and it's just been one of those days where my head is jammed straight up my ass.
 
Jason said:
wait, so you're saying that the missing pin is in the proper location, correct?

- | + | missing rpm | pwm

sorry for the stupid question and to make you repeat yourself. i like to be 100% sure, and it's just been one of those days where my head is jammed straight up my ass.
Click to expand...

Yes, it's in the proper location. The 4th pin is for PWM control so it needs to be there whereas the 3rd is the RPM signal which is not needed for both fans (only needed for one).
 
thank you sir.

any chance a mod could delete this thread entirely? sweep my stupidity under the rug? ;)
 
Nope, we all screw up occasionally and there is good information that might prevent someone else from making the same error. Console yourself that you may have saved others from the same mistake.
 
i'm actually really lucky today wasn't trash day or the cable would've been at the dump by the time i got home from work, hah.

appreciate everyone's help though. and i totally understand, bill. wasn't serious anyway. :)
 
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