My voltage reading for 12v rail is too low. Is this dangerous?

haffiizzyy
haffiizzyy Member Posts: 7

Tinkerer

edited March 1 in 2020 Archives
I recently bought a new psu (FSP 420w) to upgrade my PC which is the Acer Veriton M2640g's psu however the motherboard has a proprietary 12 pin psu power connector. Hence, I ordered a 24 to 12 pin psu adapter off of Amazon and it was delivered 3 days later. I then connected the psu to adapter and to the mobo, it boots up and I thought everything was fine. However I noticed that the monitor would sometimes flicker subtly (hard to notice the flickering), so I checked the voltage meter in bios.
The 12v rail was showing as 10.091v, sometimes spiking up to 11.1v which, was very low. I immediately asked my friend what the issue was and he told me that the wire impedance (resistance) is too high, most probably due to the 24 to 12 pin psu adapter. However, he also said that it may be due to bad psu, which was highly unlikely since I recently bought the psu. Hence, I came to this forum to seek your expert opinions on whether the issue is due to the adapter or the psu. I also wanted to inquire whether it would be safe to run the pc continue running the pc with these specs with the voltages.

Specs:
i5-6400
2x4gb DDR4 2400
Gtx 1060
128gb ssd, 1tb hdd

If not, are there any suggestions? I have recently ordered a better quality adapter off of amazon. I really don't want to replace my mobo as it would be costly. Thank you for reading my post.

Answers

  • haffiizzyy
    haffiizzyy Member Posts: 7

    Tinkerer

    Update: He told me that so long as the cpu doesn't draw more than 130w tsp, it should be fine. It this true?
  • Eddieryannbx
    Eddieryannbx Member Posts: 1 New User
    Ok 
  • billsey
    billsey ACE Posts: 31,454 Trailblazer
    12V isn't typically used for the CPU, so his 145W number doesn't make such sense. 12V is used mainly by drives and graphics. Feeding low voltage into either of those could cause weird symptoms but I don't know if it'll cause longer term issues. Do you have a VOM you could use to measure that the PSU is actually supplying? I think it tough to blame the adapter unless there's a bad crimp. That much of a voltage drop either requires a lot of power coming through or low voltage from the PSU. Enough power draw to give that voltage drop is going to be really close to melting the wires...
    Click on "Like" if you find my answer useful or click on "Yes" if it answers your question.
  • haffiizzyy
    haffiizzyy Member Posts: 7

    Tinkerer

    edited July 2020
    billsey said:
    12V isn't typically used for the CPU, so his 145W number doesn't make such sense. 12V is used mainly by drives and graphics. Feeding low voltage into either of those could cause weird symptoms but I don't know if it'll cause longer term issues. Do you have a VOM you could use to measure that the PSU is actually supplying? I think it tough to blame the adapter unless there's a bad crimp. That much of a voltage drop either requires a lot of power coming through or low voltage from the PSU. Enough power draw to give that voltage drop is going to be really close to melting the wires...
    Unfortunately I don't have a VOM device to measure the voltages. I opine that the issue is caused by the adapter, since I bought a cheap adapter from China off of Amazon. So I ordered a better quality adapter from ModDIY. Hopefully it solves the issue, else I may have to change the motherboard 😓
  • billsey
    billsey ACE Posts: 31,454 Trailblazer
    Let us know if that works. You might find it helpful to have one of the cheap VOMs handy. There are plenty around the $10-15 range.
    Click on "Like" if you find my answer useful or click on "Yes" if it answers your question.