Jump to content
SpikeSoprano

power supply 12volt drops

Recommended Posts

When I game with hardware monitor running I've noticed my 650 watt psu's 12 volt reading drops to 11.53 volts at times and the highest it reads is 11.97 volts. It has been like this almost since new which is 4 years ago. It's a LSP Ultra psu.The reason I'm asking about this now is sometimes when I oc only to 4.3 the pc goes into a no boot mode (fans start then stop  but wont enter bios until I reset cmos ).  Any opinions on this or could it be another problem ???

Share this post


Link to post
Share on other sites

The ATX specification permits the 12V rail to be anywhere between 11.4V and 12.6V so technically 11.53V is acceptable.

 

The LSP Ultra is let's say at the lower end quality wise and regardless of your problems I'd replace it with a branded unit.

Share this post


Link to post
Share on other sites

Try confirming power supply is OK with a meter first,.. by measuring Voltage,..Figure 3.18  "Back probing the power supply connectors"  http://www.informit.com/articles/article.aspx?p=31105&seqNum=12

I did the back probe a while ago on the 12 volt sata connector and it read fine so it may be another problem, I wonder is it possible the bios got wanky because if I bump the memory up to 1600 mhz (which it is rated at ) or xmp profile it also won't boot, goes into boot loop.

Share this post


Link to post
Share on other sites

The ATX specification permits the 12V rail to be anywhere between 11.4V and 12.6V so technically 11.53V is acceptable.

 

The LSP Ultra is let's say at the lower end quality wise and regardless of your problems I'd replace it with a branded unit.

I have a good Cosaire 750 I could put in it but the wires are like 10 feet long, how are Cosaire psu in ratings ?

Share this post


Link to post
Share on other sites

 

Try confirming power supply is OK with a meter first,.. by measuring Voltage,..Figure 3.18  "Back probing the power supply connectors"  http://www.informit.com/articles/article.aspx?p=31105&seqNum=12

I did the back probe a while ago on the 12 volt sata connector and it read fine so it may be another problem, I wonder is it possible the bios got wanky because if I bump the memory up to 1600 mhz (which it is rated at ) or xmp profile it also won't boot, goes into boot loop.

 

 

It's the +3.3v and +5v of power you want to check,.. first test pin-8 on the 24-pin ATX connector. If not within range,.. the system never sees the Power_Good signal and therefore does not start or run properly. 

 

24-pin connector pin-out :  https://www.lifewire.com/atx-24-pin-12v-power-supply-pinout-2624578

Edited by Braegnok
  • Like 1

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×