ASRockH170M-ITX/ac won't POST

Ok. Now it's time to remove it all from the case it's presently in, and build it up atop the BARE box the MB came in.

permelquedon wrote: I got frustrated with the build so I had to let it alone for awhile, but I am coming back to it now with a vengeance.  (This is literally the most trouble I've ever had trying to get a system built and I started in the 90s!) Anyway, I've got it out of the case with the power button jumpered and I'm still seeing the exact same behavior as before.  When I turn on the power, I hear a faint "click" from the power supply and nothing else happens. I've tried 2 different power supplies, 2 different sets of power cables, 2 sets of RAM, 2 MOTHERBOARDS!  And still the darn thing will not power on.  This is after I had ASRock support send me a 1.3 BIOS that would supposedly support my Pentium G4400. So I've tried about everything I can think of now.  Can anyone offer up what I should try next? Thanks!

Please try the following:

First, so sorry but I must ask, do you have the power cable from the PSU to the four pin CPU power connector on the board connected?

Remove the jumper from the power button pins on the system panel header, which I assume is how you are jumping the power button. You should only need to momentarily short the two pins on the system panel header to get the board running.

Now that you have the new BIOS chip installed, at least do a BIOS clear with the jumper. You may want to do a full BIOS clear by removing the battery from the board and moving the BIOS jumper to the clear position. The full BIOS clear may be necessary, which may take some time. The capacitors in your board should not have much of a charge, so it may not take hours to completely clear. Replace battery and put the BIOS jumper on the normal position.

With only the PSU, CPU, CPU cooler, and memory connected to the board, try and start it by shorting the power button pins with a screwdriver momentarily.

Even with a BIOS version that did not support your CPU, I can't imagine the board just doing nothing, and all that happens is a click sound from the PSU.

I'm not saying that did/does not happen!

Yes it would fail to POST, and the POST beep speaker would give the CPU failure signal, but the board would at least start, fans would spin, etc.

But in your case, the CPU cooler fan does not start to spin, or at most just jerks for a moment and then does nothing, right?

Given all this, doesn't that seem like the PSU is shutting itself off due to a fault it is detecting? Its protection circuitry is shutting it off, right?

If you agree, the question becomes, what is causing the PSU to protect itself?

It sounds like you know enough to not let the board short itself out from the bottom, when just sitting outside of a PC case. So is the stock CPU cooler fan shorted? Or a cable from the keyboard or mouse?

I know this is your second board of the same model, etc. But IMO something is stopping the PSU from starting. I know you used two PSUs, which is another reason why I feel something is keeping the PSU from starting.

Thanks for the reply.