7 ms·

A new semi-passive 850-watt fully modular PSU is around EUR 130, the Noctua fan around EUR 30. I guess if you know electronics and how to safely handle the PSU

A new semi-passive 850-watt fully modular PSU is around EUR 130, the Noctua fan around EUR 30. I guess if you know electronics and how to safely handle the PSU internals, the risk of injury is low, but I personally would not risk it for EUR 100. Also, if the only problem was the noisy fan, I guess selling it used would have returned most of the investment, leaving him with like EUR 50 in added cost. Compared to the price of a modern gaming PC, that's nothing (also avoiding not risking your life).

jojobas 1y ago
C grade high school physics understanding makes the risk exactly zero. Selling defective stuff without declaring is bad mojo, with declaring it just delegates the pain in the bum to someone else..
- doubled112 1y ago
  I’ve been tearing things open after ignoring the “dangerous if opened” stickers since I was 8 years old. I’m in my 30s, you’d think something would have caused me harm by now, but no.
  - jojobas 1y ago
    There's a fair bit of survivorship bias in this. That said, modern power supplies use "bleeder resistors" to discharge the capacitors once powered off.
    - scottlamb 1y ago
      > There's a fair bit of survivorship bias in this. Is there? This kind of statement has the potential to exhibit survivorship bias, but I feel like the opposite—"12-year-old dies replacing a power supply fan"—would make headlines. Definitely haven't seen that. Capacitors should be respected for sure, but people don't routinely die in DIY electronics tasks.
      - jojobas 1y ago
        Electrical injuries claim some 1000 lives per year in the states, and 20% of all electrical injuries are sustained by children (lethal and non-lethal). I don't think every electrocuted child makes even local headlines.
        scottlamb 1y ago
        Sobering for sure, but I think vanishingly few of those are from residual energy in capacitors in unplugged appliances during disassembly, [1] and certainly far from the "this forum is missing x people just like doubled112 because of tragedies" that I imagine when you say "there's a fair bit of survivorship bias in this". [1] a quick search mentions things like damaged cords, the classic metal object into the outlet, etc. I installed tamper-resistant outlets everywhere in my house to prevent the latter as part of child-proofing. I think they're mandatory now in new construction. I also may have gone a bit overboard trying to instill caution in my children about this this particular risk; my son tonight asked me if he was okay after his sleeve brushed against the metal part of a USB-C connector while he was plugging in his tablet.
        jojobas 1y ago
        I rather meant statements like "I did X and I didn't die" are open to survivorship bias, than asserting many must have died from this particular cause. I believe bleeder resistors are written in blood though, I vaguely remember electrocution tales from the times when people were expected to replace vacuum tubes in radios.
        account42 1y ago
        That's more than an order of magnitude less than fatalities from cars. In my book, that puts it into "be careful" territory but far from "don't even think about it".
        jojobas 1y ago
        Nearly everyone deals with roads every single day. Very few people disassemble electric devices per day. The risk base is not comparable. Also https://xkcd.com/795/ https://xkcd.com/795/
    - account42 1y ago
      A lot of the risk is simply overstated. Yes, bad things can happen but that also goes for crossing the road yet we don't limit that to certified professionals. Just have some basic understanding of electricity, common sense, don't attempt the work while tired and you'll be fine.
tcdent 1y ago
I will put hundreds of dollars in Noctua fans into a second-hand chassis without thinking twice. It's sometimes uneconomical from a cost-ratio perspective, but it is crucial to making datacenter-grade equipment actually useable at home.
- ahartmetz 1y ago
  If you need pretty good fans for cheap as dirt, there is also Arctic Cooling.
  - PaulKeeble 1y ago
    They just never last. Arctic fans perform really well especially for their price but they all seem to develop problems. I have probably bought about 15 different Arctic fans from the F and P range and none of them survived 5 years, most were dead or developed noise within 1-2 years. Noctua on the other hand the old 80mm fan from the early 2000s still works just fine and remains quiet. Noctua fans are crazy reliable, they cost more too but I would suspect over the life of the fan they end up similar priced or cheaper.
    - ahartmetz 1y ago
      Arctic fans seem to last 10+ years for me. I haven't bought any recently though and I run them at 500 rpm or so, that's my strategy: many and large fans, running slowly.
  - mrbigbob 1y ago
    while arctic make fairly good high performing fans for cheap their bearings/acoustics are kind of bad. i bought 5 of the original p12 max fans with the ball bearings. they all made a chirping noise at various rpms (even after getting 5 new ones from arctic). the new p12 pro fans perform great but around 1200 rpms the motor is very loud and annoying really wish arctic would now focus on the acoustics of their fans because its there weakest point. i wouldnt mind spending a bit more per fan if the sound profile wasnt just straight terrible which personally theirs are to me at the moment
- 1y ago
hobs 1y ago
Hilarious to read this on "hacker news" - replacing a standard fan is too dangerous! This is not styropyro.
- ycombinatrix 1y ago
  PSU capacitors can kill you, even after being disconnected from mains power.
- victorhooi 1y ago
  I think perhaps you might have not read the entire article? =) The danger isn't so much in the fan, but in that the fan is INSIDE OF A COMPUTER PSU. There are mains AC voltages (220V, or 110V) here, and even if unplugged (which is should be) there are also capacitors in there, which you should definitely be cautious of. I've worked in DC (datacenters) before - and I've seen people accidentally drop screws into power supplies...and well, electrical arc, boom, you can guess the rest. And in a domestic situation, a 4" cooling fan (yes, I know, larger) stopped suddenly due to a motor issue, and send flying bits of plastic shrapnel around (always wear eye protection!). This isn't quite like tinkering with your little Arduino board, or Raspberry Pi. If you did read the article =(.... I think that's a bit arrogant and disingenuous to make fun of people saying you should be cautious around things that are connected to AC mains, or that involve capacitors.
  - umbra07 1y ago
    > I've seen people accidentally drop screws into power supplies...and well, electric boom, you can guess the rest. Are we talking like, bad electrical shock, hospitalization, death, etc?
  - hobs 1y ago
    I appreciate that most folks talking about power on HN are talking about computers, but I decided to not become an electrician in an earlier life. Taking standard precautions doesn't mean you suddenly shy away from doing basic maintenance. You can use iso alcohol to clean things even if its flammable, just don't use an open flame at the same time.

jojobas 1y ago

C grade high school physics understanding makes the risk exactly zero. Selling defective stuff without declaring is bad mojo, with declaring it just delegates the pain in the bum to someone else..

doubled112 1y ago
I’ve been tearing things open after ignoring the “dangerous if opened” stickers since I was 8 years old. I’m in my 30s, you’d think something would have caused me harm by now, but no.
- jojobas 1y ago
  There's a fair bit of survivorship bias in this. That said, modern power supplies use "bleeder resistors" to discharge the capacitors once powered off.
  - scottlamb 1y ago
    > There's a fair bit of survivorship bias in this. Is there? This kind of statement has the potential to exhibit survivorship bias, but I feel like the opposite—"12-year-old dies replacing a power supply fan"—would make headlines. Definitely haven't seen that. Capacitors should be respected for sure, but people don't routinely die in DIY electronics tasks.
    - jojobas 1y ago
      Electrical injuries claim some 1000 lives per year in the states, and 20% of all electrical injuries are sustained by children (lethal and non-lethal). I don't think every electrocuted child makes even local headlines.
      - scottlamb 1y ago
        Sobering for sure, but I think vanishingly few of those are from residual energy in capacitors in unplugged appliances during disassembly, [1] and certainly far from the "this forum is missing x people just like doubled112 because of tragedies" that I imagine when you say "there's a fair bit of survivorship bias in this". [1] a quick search mentions things like damaged cords, the classic metal object into the outlet, etc. I installed tamper-resistant outlets everywhere in my house to prevent the latter as part of child-proofing. I think they're mandatory now in new construction. I also may have gone a bit overboard trying to instill caution in my children about this this particular risk; my son tonight asked me if he was okay after his sleeve brushed against the metal part of a USB-C connector while he was plugging in his tablet.
        jojobas 1y ago
        I rather meant statements like "I did X and I didn't die" are open to survivorship bias, than asserting many must have died from this particular cause. I believe bleeder resistors are written in blood though, I vaguely remember electrocution tales from the times when people were expected to replace vacuum tubes in radios.
      - account42 1y ago
        That's more than an order of magnitude less than fatalities from cars. In my book, that puts it into "be careful" territory but far from "don't even think about it".
        jojobas 1y ago
        Nearly everyone deals with roads every single day. Very few people disassemble electric devices per day. The risk base is not comparable. Also https://xkcd.com/795/ https://xkcd.com/795/
  - account42 1y ago
    A lot of the risk is simply overstated. Yes, bad things can happen but that also goes for crossing the road yet we don't limit that to certified professionals. Just have some basic understanding of electricity, common sense, don't attempt the work while tired and you'll be fine.

tcdent 1y ago

I will put hundreds of dollars in Noctua fans into a second-hand chassis without thinking twice. It's sometimes uneconomical from a cost-ratio perspective, but it is crucial to making datacenter-grade equipment actually useable at home.

ahartmetz 1y ago
If you need pretty good fans for cheap as dirt, there is also Arctic Cooling.
- PaulKeeble 1y ago
  They just never last. Arctic fans perform really well especially for their price but they all seem to develop problems. I have probably bought about 15 different Arctic fans from the F and P range and none of them survived 5 years, most were dead or developed noise within 1-2 years. Noctua on the other hand the old 80mm fan from the early 2000s still works just fine and remains quiet. Noctua fans are crazy reliable, they cost more too but I would suspect over the life of the fan they end up similar priced or cheaper.
  - ahartmetz 1y ago
    Arctic fans seem to last 10+ years for me. I haven't bought any recently though and I run them at 500 rpm or so, that's my strategy: many and large fans, running slowly.
- mrbigbob 1y ago
  while arctic make fairly good high performing fans for cheap their bearings/acoustics are kind of bad. i bought 5 of the original p12 max fans with the ball bearings. they all made a chirping noise at various rpms (even after getting 5 new ones from arctic). the new p12 pro fans perform great but around 1200 rpms the motor is very loud and annoying really wish arctic would now focus on the acoustics of their fans because its there weakest point. i wouldnt mind spending a bit more per fan if the sound profile wasnt just straight terrible which personally theirs are to me at the moment
1y ago

hobs 1y ago

Hilarious to read this on "hacker news" - replacing a standard fan is too dangerous! This is not styropyro.

ycombinatrix 1y ago
PSU capacitors can kill you, even after being disconnected from mains power.
victorhooi 1y ago
I think perhaps you might have not read the entire article? =) The danger isn't so much in the fan, but in that the fan is INSIDE OF A COMPUTER PSU. There are mains AC voltages (220V, or 110V) here, and even if unplugged (which is should be) there are also capacitors in there, which you should definitely be cautious of. I've worked in DC (datacenters) before - and I've seen people accidentally drop screws into power supplies...and well, electrical arc, boom, you can guess the rest. And in a domestic situation, a 4" cooling fan (yes, I know, larger) stopped suddenly due to a motor issue, and send flying bits of plastic shrapnel around (always wear eye protection!). This isn't quite like tinkering with your little Arduino board, or Raspberry Pi. If you did read the article =(.... I think that's a bit arrogant and disingenuous to make fun of people saying you should be cautious around things that are connected to AC mains, or that involve capacitors.
- umbra07 1y ago
  > I've seen people accidentally drop screws into power supplies...and well, electric boom, you can guess the rest. Are we talking like, bad electrical shock, hospitalization, death, etc?
- hobs 1y ago
  I appreciate that most folks talking about power on HN are talking about computers, but I decided to not become an electrician in an earlier life. Taking standard precautions doesn't mean you suddenly shy away from doing basic maintenance. You can use iso alcohol to clean things even if its flammable, just don't use an open flame at the same time.