Quote: Originally Posted by Frankino
guys, this is weird, really
I built an ATX cable to easy check voltages and drain for each rail
I did some tests, 2.5A on the 3,3v, 3,5A on the 5v and 1,2A oh the 12v rail
as you can se,, well into opus specs.
but this is NOT the weird part
during my tests I checked 12v, then 5v and then 3.3v
well, when I was testing the 3.3v drain (placing my tester between mainboard and psu) I noticed that the pc for the first time booted up fine. ok, it's a coincidence. I remove my tester and repower the pc and the pc won't start. Ok. Then I reconnected my tester (again in serie) and my pc power up normally. I started to think it couldn't be a coincidence again.. well after about 10 times removing and replugging my tester I come to the fact that if I connect the my tester the system boots up properly; if I remove it the systen won't start. I cannot believe myself when I realized it but, guys, these are the facts. Does anyone have the slightest idea what's going on?
by the way, my tester reads 3.44v at the 3.3v points, I don't know if it may be a problem
Check the impedance of your tester. If it's a cheap one the impedance may be low and what it is doing is causing the voltage to drop and limiting the current on the 3.3 rail.
In theory, you could connect a resistor of the same value as the impedance of your tester in place of the tester (if that makes sense) it would then boot up. (Don't recommend it as a solution though).
It sounds like the Opus is running out of spec on that rail and that is what is causing your problem.
If your tester has a low impedance then the readings you are getting may be incorrect.
It always pays to use a high quality high impedance meter for solving problems like this.
Hope this helps some.