Tom's Hardware > Forum > CPU & Components > Power Supplies, PC Cases & Case Mods > Testing power supply

Testing power supply

Forum CPU & Components : Power Supplies, PC Cases & Case Mods - Testing power supply

Tom's Hardware: Over 1.4 million members in 6 different countries available to answer all your high-tech questions. Sign up now! Its free!
Ask the community Add a reply
Word :    Username :           
 
FatBear   11-24-2005 at 03:04:17 PM

Hi,

Anyone knows will the power supply turns on (eg fan starts to rotate) if I just attach to the power by itself, without to the motherboard? I wanted to test whether this new power supply I have just bought is working?? Thankz..

Add a reply
Sponsored Links
Register or log in to remove.
fishmahn   11-28-2005 at 09:22:30 PM
- 0 +

Its never a good idea to run a power supply without any load (i.e. mobo and/or disk drives).

However, you can test a PSU to see if the fans work (plug in a fan or disk drive first to be safe) by shorting the green wire from 20/24 pin mobo connector to any black wire on the connector.

Mike.

Reply to fishmahn
  11-29-2005 at 10:29:09 PM
- 0 +

Quote :

Its never a good idea to run a power supply without any load (i.e. mobo and/or disk drives).



Why do you say this? I can't imagine what the technical reason would be.

Add a reply
fishmahn   11-29-2005 at 11:20:06 PM
- 0 +

It is a switching PSU. That is the technical reason (if you know about switching PSUs - which I don't, but I got it from someone who does) I don't know the technical details... hang on, lemme look it up...

Here is a short and not technical version. If you want a more technical version I can try to dig one up for you.

The ATX design guide (here's on, its on pg 29) says that the PSU must allow for the condition without damage, but that doesn't mean it is done well, or that they test for it... (i.e., most psu's are crap, and even if it does have that safety feature its better safe than sorry).

Mike.

Reply to fishmahn
  11-30-2005 at 04:13:55 AM
- 0 +

Yeah I do know a little about them. Part of my job is designing them into the products my company sells.

I have a couple of products we sell piles of every day which are standalone switching supplies. Both are perfectly happy sitting unloaded for all time maintaining specified output voltage and continuing to work as specified when a load is applied. I can tell you with no amount of uncertainty not all switching supplies fail when there is no load applied.

I don't know what is going on with that link you supplied. Either those guys are smoking the good stuff or there is some arcane ATX spec I am unaware of which requires/allows this behavior. If it is the spec thing then that certainly doesn't mean all switchers can't maintain good behavior unloaded.

In my opinion supplies that don't behave well under all loading conditions shouldn't even get out the door. That is just bad design practice. I am shocked to consider the possibility that there are companies who would even offer such crap to their customers and they have to give them money for it.

Add a reply
Ask the community Add a reply
Tom's Hardware > Forum > CPU & Components > Power Supplies, PC Cases & Case Mods > Testing power supply
Go to:

There are 804 identified and unidentified users. To see the list of identified users, Click here.

Forum map
Bestofmedia Forum ©
2000-2009 Bestofmedia Group
Page generated in 1.621 seconds
Please mind

You are about to answer a thread that has been inactive for more than 6 months.
If you still wish to proceed, please ensure that your posting is original and does not duplicate or overlap any prior responses to this thread.

Add a reply Cancel
Sponsored links
  • Ask the community now
  • Publish
Ad
Related Topics
See all relatives topics
They won a badge
Join us in greeting them