ocyang

Today I tried with CoolerMaster Real Power 750W, it even can not start at beginning. So I go back with Antec 500W. After jump start, I check the 12V voltage at BIOS, it show 12.48V, which is 4% over 12V. So I believe with cool start, it may around 5% and MB will try shut PS off for protection. I don't thing it is under power problem since I only use one GT6800 and after power on, every things is running fine for years. I will try replace MB. Do you think ASUS is also picky with power supply?

But why it always can work for few month and then stop working? (The PSU still work fine by it self if I short black and green pins) It must be the MB shut off the PSU when detect something out of range.

I bought NF4 Ultra-D two years ago with Antec Smart Power 500W. After 6 month It can not boot up. (only one yellow LED on, no bios, no fan). Then I tried replace MB, it still failed. After replace PSU with same model, it start work fine for 3 month. Then same thing happened, so I replace with same model PSU again. Then after one year, same thing happened again.:sad: But this time I replace with different PSU(650W), but it only worked for 3 week then it stop working. When I was trying take out PSU, I forgot unplug power cord, so when I unplug the main 24pin cable, system back online. So at first I think it may the connector problem, but it is not after very careful check. The PSU I am able to jump start with short green and black pins. If I do that, the system is working fine after power up. (I also tested broken Antec PSU, it also working fine with jump start) So do you think the problem is the picky MB? Maybe because after while, the PSU output voltage changed and out of range. (from bios they are looks perfect fine, about 1% over) Anyway to disable MB to shut off power supply from BIOS? Or only way is to replace MB? Thanks!