When to replace?

[Jeff G]

At what point is it recommended to replace the PSU?
My 3.3v is averaging 3.3v, but my 5v is averaging 4.9v and my 12v is averaging 11.9v according to HWinfo64 over the coarse of several hours of computer usage that included photo/video editing and gaming.
Just wondering if this is a sign that it's starting to slow down and maybe should be retired?

 

[don256us]

Those numbers are right on target. Power supplies get a 5 - 10% tolerance depending on the leg.
https://www.lifewire.com/power-supply-voltage-tolerances-2624583

 

[Nebulous]

Yup I agree with Don. Those rails are within spec. Now of course nothing wrong with a new psu if you really want one tho

 

[Jeff G]

Now of course nothing wrong with a new psu if you really want one tho

That is a whole other problem
I always want new parts! (I really have been eyeing up going modular lately, but PSU prices seem to be on the incline with everything else)

 

[Tech Tweaker]

My current rule of thumb is to replace when it's five years old or older (assuming warranty is 5 years or less). Probably less for lower quality (sketchy or questionably-branded) power supplies, perhaps more like 2-3 years for them as really low quality ones tend to have only 1-2 year warranties (maybe three in some cases).

That said though, I have a Corsair CMPSU-750TX (TX750W v1) that's 7 years old now and still as solid on the rails as it was when it was new (and an HX620 that's probably 7-8 years old now and still solid on its rails, and an HX520 that's about the same age I think). I'm only considering replacing the TX750 because the coil whine when it's under load is really irritating to me.
12V - 12.28V
5v - 5.01V IIRC
3.3V - 3.38V IIRC

Spec for the 12v line is min 11.4v (though I had one that output only 11.4v and was unstable), and max is 12.6v. Personally I'd rather go no lower than 11.6-11.7v under load for a safety margin in case of vDroop.

Supply (V) Tolerance Range, min. to max. (V) Ripple, p. to p., max. (mV)
+5 ±5% (±0.25 V) +4.75 V to +5.25 50
−5 ±10% (±0.50 V) −4.50 V to −5.50 50
+12 ±5% (±0.60 V) +11.40 V to +12.60 120
−12 ±10% (±1.20 V) −10.80 V to −13.20 120
+3.3 ±5% (±0.165 V) +3.135 V to +3.465 50
+5 standby ±5% (±0.25 V) +4.75 V to +5.25 50

https://en.wikipedia.org/wiki/ATX#Physical_characteristics

 

[Jeff G]

My current rule of thumb is to replace when it's five years old or older (assuming warranty is 5 years or less). Probably less for lower quality (sketchy or questionably-branded) power supplies, perhaps more like 2-3 years for them as really low quality ones tend to have only 1-2 year warranties (maybe three in some cases).

That said though, I have a Corsair CMPSU-750TX (TX750W v1) that's 7 years old now and still as solid on the rails as it was when it was new (and an HX620 that's probably 7-8 years old now and still solid on its rails, and an HX520 that's about the same age I think). I'm only considering replacing the TX750 because the coil whine when it's under load is really irritating to me.
12V - 12.28V
5v - 5.01V IIRC
3.3V - 3.38V IIRC

Spec for the 12v line is min 11.4v (though I had one that output only 11.4v and was unstable), and max is 12.6v. Personally I'd rather go no lower than 11.6-11.7v under load for a safety margin in case of vDroop.

Supply (V) Tolerance Range, min. to max. (V) Ripple, p. to p., max. (mV)
+5 ±5% (±0.25 V) +4.75 V to +5.25 50
−5 ±10% (±0.50 V) −4.50 V to −5.50 50
+12 ±5% (±0.60 V) +11.40 V to +12.60 120
−12 ±10% (±1.20 V) −10.80 V to −13.20 120
+3.3 ±5% (±0.165 V) +3.135 V to +3.465 50
+5 standby ±5% (±0.25 V) +4.75 V to +5.25 50

https://en.wikipedia.org/wiki/ATX#Physical_characteristics

Mine is a corsair 750w as well, and is probably approaching the 7 year mark. I'm on the fence over it, part of me wants a modular one finally and part of me doesn't want to spend any more money!

 

[Richo999]

These days they give 5-10 years on a good quality PSU, after the warranty ends I will replace a PSU. As long you clean your fans and inside the PSU (this will void warranty though) your only concern are the caps which are good quality on a quality PSU.

 

[Tír na nÓg]

Mine is a corsair 750w as well, and is probably approaching the 7 year mark. I'm on the fence over it, part of me wants a modular one finally and part of me doesn't want to spend any more money!

If it's not broken...

 

[Jeff G]

If it's not broken...

Which is why I'm still running it 7 years later, darn thing just won't break!

 

[Tír na nÓg]

Man, take it as a gift

 

[Richo999]

Which is why I'm still running it 7 years later, darn thing just won't break!

A properly maintained PSU will last decades, I can know. Still have a 250W AT PSU unbranded (with its original caps) from my parents 486, I used in a retro rig but nowadays I use it to test other stuff like fans and hdds and on occasion a system.

 

[deathman20]

I know that feeling you have. I have an older SilverStone PSU DA750 unit. I believe I got it sometime in 2009.. don't have accurate records. It still holds rail voltage and plays perfectly fine. Never really maxed out the PSU, think the largest load I ever had on it was 550W. Though last year I replaced her in my main rig which would make it roughly 7 years of usage (non 24/7 running). It still lives with my secondary PC just a little lighter loads still (around 300W these days).

 

[ATMINSIDE]

A properly maintained PSU will last decades, I can know. Still have a 250W AT PSU unbranded (with its original caps) from my parents 486, I used in a retro rig but nowadays I use it to test other stuff like fans and hdds and on occasion a system.

Care to comment as to what proper PSU "maintenance" is?

Also worth noting to everyone in this thread; software is not to be relied on for PSU voltage readings. Use your DMM!!

 

[Richo999]

Care to comment as to what proper PSU "maintenance" is?

Also worth noting to everyone in this thread; software is not to be relied on for PSU voltage readings. Use your DMM!!

proper maintenance is what I already said
clean the fans and replace them before they die (so within 10 years of last replacement) and check caps for bulging or replace every 10-20 years (bulging is a CLEAR sign of caps being "kaput" they might still function or not, however the cap can be "kaput" even when not bulging). A PSU is garanteed to fail if it overheats (dust build / broken fans) or has bad caps, any other reason is either bad luck or stupidity (usually people who modify their PSU electrical system without proper knowledge).
Ok I admit I forgot to add that capacitors like current every now and then so if you old hardware that you do not use on a daily base should be turned on every 3 months at the minimum for capacitor longevity (measering caps require special equipment, A colleague at work did this to my AT PSU which were still well within rated specs).
also its ALWAYS worth investing in a quality PSU (I am by no means a expert in this area so I rely on reviews for this, as I know the risks of using cheap PSU), you get that 5-10 year warranty for a reason

 

[ATMINSIDE]

proper maintenance is what I already said
clean the fans and replace them before they die (so within 10 years of last replacement) and check caps for bulging or replace every 10-20 years (bulging is a CLEAR sign of caps being "kaput" they might still function or not, however the cap can be "kaput" even when not bulging). A PSU is garanteed to fail if it overheats (dust build / broken fans) or has bad caps, any other reason is either bad luck or stupidity (usually people who modify their PSU electrical system without proper knowledge).
Ok I admit I forgot to add that capacitors like current every now and then so if you old hardware that you do not use on a daily base should be turned on every 3 months at the minimum for capacitor longevity.

So... just like the rest of the system. Dust regularly, check for bad fans, and make sure caps aren't bulging...
"Proper maintenance" isn't a term used frequently for a PSU, so it's good to specify.

 

[Richo999]

So... just like the rest of the system. Dust regularly, check for bad fans, and make sure caps aren't bulging...
"Proper maintenance" isn't a term used frequently for a PSU, so it's good to specify.

my bad, will try to specify more clearly in the future

 

[SPL Tech]

You replace the PSU when it stops working. Replacing it just because it's x number of years old is ridiculous and best accomplishes wasting money and making NewEgg richer. We're talking about a desktop computer for personal use, not an enterprise server farm for the stock market. I have had the same 750W Corsair PSU for almost 10 years and I ran it fairly hard. I've been through give five overclocked computer builds including three SLI builds. I used to run GTX 265s which were complete power hogs. The PSU still works perfectly fine and the fan doesent even go over 50% after extended gaming. I opened it up the other day to clean it out and after cleaning it basically looks brand new. Still works the same today as it did on day one. If it aint broke, dont fix it.

 

[Alaric]

You replace the PSU when it stops working.

Yup. Right after it corrupts your OS and you lose important data.

If it aint broke, dont fix it.

They don't always die in their sleep. When a 450v capacitor *#@!& the bed under load it ain't pretty. Honestly, for the cost, it's cheap insurance.

 

[Richo999]

You won't notice a PSU dying, if your lucky your multi thousand will survive but it could just short your entire system for what? A PSU worth 50-150 every 5-10 years? Imo not worth it for such a crucial system in your computer.

 

[mackerel]

Throughout the years I've been doing distributed computing to varying degrees. The strategy has been to optimise cost. That has included at times using the PSUs that most forums will tell you to run away from. I've never had anything die from a PSU failing, other than the PSU itself of course. On the cheap PSUs, after running a year or two under load 24/7 the system may go unstable, probably saggy voltages but I never measured. Replace and away you go again. One of these low cost PSUs costs a fraction of what is usually considered a good one. OTOH I can't recall the last branded PSU going bad, and some of mine are really old now. For example, I still use a Corsair TX750 which was originally bought for my Sandy Bridge system, and that isn't the oldest. I don't tend to buy cheap PSUs any more, unless it comes with a case or other system, then might as well use it if I have it anyway.