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Brand New Power Supply - 3.3v rail out of spec?

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I just picked up a Corsair CX430 430W power supply from newegg for $24.99 after rebate to replace a crappy PSU for my home server that came with the case (the case + PSU was $29.99, the PSU was really loud and only came with 2 SATA connectors).

Anyway, the new PSU just arrived from newegg and I hooked it up to my Antec PSU tester (multimeter is at home) and it's showing that the 3.3V rail is out of spec by almost 20%. Everything else looks fine, it's just the 3.3V rail that is out of spec. Is this going to cause any issues or should I just RMA this back to Corsair?

 
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Wow, that's really low. The CX430 usually tests very well. The 3.3v VR test at TPU had it dipping at most 3.6%, and averaging more like 3.24%.

The jonnyGURU test showed very good results too, not wavering much even in the hot box.

Barring a problem with your tester, which seems unlikely given it's 5 and 12 volt readings, I'd say it looks like you're going to have to RMA it.
 

sneekypeet

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What does software like AIDA 64 or the motherboard software show, just out of curiosity. Also I would hook up a digital multi-meter and verify the actual voltage. If it is out of spec ( +/- 10%) I would send it back.
 

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I second the Digital Multi Meter suggestion.

Though is there anything in a modern computer that even uses the 3.3v rail?
 

sneekypeet

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IDk last time I had 3.3V issues was on a DFI Nf4
 
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Just run it. It will be fine.
 
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I would not trust the tester - measure the voltage with a multimeter.
 
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I would not trust the tester - measure the voltage with a multimeter.

I bought the PSU while I am on vacation so I won't be able to test it until next week. But would the tester really be at fault if it was giving "decent" 12V and 5V readings and low 3.3V readings?
 

newtekie1

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I bought the PSU while I am on vacation so I won't be able to test it until next week. But would the tester really be at fault if it was giving "decent" 12V and 5V readings and low 3.3V readings?

Sure, if the 3.3v circuit on the tester is broken somehow. I had a test like that that would consistently give bad 5v readings. It turns out the pin on the tester for reading 5v was oxidized so it always read low. After cleaning the pin with some contact cleaner the readings went back to normal. Never did figure out why just that one pin got oxidized.

Do you have another PSU that you can test to see what the tester says with another unit?
 

novatech

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PSU Corsair 3.3v out of spec

I bought the PSU while I am on vacation so I won't be able to test it until next week. But would the tester really be at fault if it was giving "decent" 12V and 5V readings and low 3.3V readings?

It should be said we have purchased 11 PSU units from Corsair that all exhibit this issue all voltages are fine except the 3.3 v is reading 2.7v which is way out of spec.

You are not alone, we are sill trying to get all the defective unit sent back for good ones.
the CX600 & CX430 as well as others are no longer manufactured by SeaSonic as they used to be in the last year since Corsair is no longer using Seasonic for these unit we have had a rash of returns and out of spec PSU units.

Generally, supply voltages must be within ±5% of their nominal values at all times. The little-used negative supply voltages, however, have a ±10% tolerance. There is a specification for ripple in a 10 Hz–20 MHz bandwidth:[8]

Supply [V] Tolerance Range (min. to max.) Ripple (p. to p. max.)
+5 VDC ±5% (±0.25 V) +4.75 V to +5.25 V 50 mV
−5 VDC ±10% (±0.50 V) –4.50 V to –5.50 V 50 mV
+12 VDC ±5% (±0.60 V) +11.40 V to +12.60 V 120 mV
−12 VDC ±10% (±1.2 V) –10.8 V to –13.2 V 120 mV
+3.3 VDC ±5% (±0.165 V) +3.135 V to +3.465 V 50 mV
+5 VSB ±5% (±0.25 V) +4.75 V to +5.25 V 50 mV

8 ^ a b "ATX Specification Version 2.2". 090503 formfactors.org
http://en.wikipedia.org/wiki/ATX
 

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It should be said we have purchased 11 PSU units from Corsair that all exhibit this issue all voltages are fine except the 3.3 v is reading 2.7v which is way out of spec.

You are not alone, we are sill trying to get all the defective unit sent back for good ones.
the CX600 & CX430 as well as others are no longer manufactured by SeaSonic as they used to be in the last year since Corsair is no longer using Seasonic for these unit we have had a rash of returns and out of spec PSU units.

Generally, supply voltages must be within ±5% of their nominal values at all times. The little-used negative supply voltages, however, have a ±10% tolerance. There is a specification for ripple in a 10 Hz–20 MHz bandwidth:[8]

Supply [V] Tolerance Range (min. to max.) Ripple (p. to p. max.)
+5 VDC ±5% (±0.25 V) +4.75 V to +5.25 V 50 mV
−5 VDC ±10% (±0.50 V) –4.50 V to –5.50 V 50 mV
+12 VDC ±5% (±0.60 V) +11.40 V to +12.60 V 120 mV
−12 VDC ±10% (±1.2 V) –10.8 V to –13.2 V 120 mV
+3.3 VDC ±5% (±0.165 V) +3.135 V to +3.465 V 50 mV
+5 VSB ±5% (±0.25 V) +4.75 V to +5.25 V 50 mV

8 ^ a b "ATX Specification Version 2.2". 090503 formfactors.org
http://en.wikipedia.org/wiki/ATX

Software or proper measuring?

And about software readings: DO NOT TRUST THEM. Seriously. Don't. ATM my 12V line is sitting at 7V, according to software.
 

de.das.dude

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i had a friend with a cx600, had issues with the 3.3V as well. they replaced his in a day. his was a physical loose connection prob though.

so might be the same issue. you can use a multimeter to check.
 
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And that's why you shouldn't buy those unexccusably poor quality Corsair PSU's. Their higher end ones, no complaints, but those new CX units kinda suck.

But then again with no load and using a useless "PSU Tester" who knows... if the computer works the out of spec 3.3V should fix itself.
 
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yea software measurement is crap
take one psu build identical systems with different motherboards all of them will report different voltages with the same psu
 
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Benchmark Scores Faster than yours... I'd bet on it. :)
Also I would hook up a digital multi-meter and verify the actual voltage. If it is out of spec ( +/- 10%) I would send it back.
Software is very unreliable. Use the MM if you have one...Also, spec is 5%... the value must be within 5% of 3.3v. :toast:
 

novatech

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Software or proper measuring?

And about software readings: DO NOT TRUST THEM. Seriously. Don't. ATM my 12V line is sitting at 7V, according to software.

This was verified with DMM & with Dedicated PS tester
 
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