+12 voltage dorps to 0.12

bgshankar1969

Distinguished
Nov 11, 2011
10
0
18,510
Hello,

I have weird problem. CPU fan is at constant speed 1059, it used to adjust according to CPU temp. After observation I found that +12 voltage drops to 0.12 on some railings. CPU fan stops when it should rotate at highest speed. It is working at normal speeds when no load on CPU
 
You are getting a bad reading for the 12v. Check the bios reading; any reading between 11.7 and 12.3 is good. For the cpu fan, your motherboard bios may have a smartfan setting which you can change, but some oem systems by dell, etc. may not be adjustable. You probably are fine. Enjoy the quiet. If you find a calibrate function in the hardware monitor section with smartfan, use it, then select "quiet" if it's an option.
 

bgshankar1969

Distinguished
Nov 11, 2011
10
0
18,510
Mine is IBM xSeries 206. Bios is not showing any thing regarding voltages neither smartfan settings.

Previously I used to hear CPU fan zooming sound when processor is at heavy load. Since few days, there sounds are there.

I installed Speedfan a doubt in mind. It is showing 3 different blocks for voltages. In third ( last block), there are 3 readings

+3.3V: 3.28
+5V: 5.11
+12V: 0.12V

I think my PSU is wearing, please advise.
 
Obviously your software is reading it wrong. If you 12 V rail was even at 10 V your system wouldn't be able to run, that low and your motherboard wouldn't be able to do anything.

Get yourself a digital multimeter and use it to check the voltages, since your BIOS doesn't report voltages its your only chance for accurate readings.