Crosshair VIII Hero won't even power on with new 3900x, cpu or mobo?

[blppt]

I'm trying to figure out whether the motherboard or the cpu is the culprit here---using a 3900x, properly seated, and we get the multicolored LEDs and "Start" button illuminates, but neither the start button nor the front panel connected power switch (confirmed properly seated) does anything whatsoever---no movement of any of the fans, no code appears on the 2 digit readout. I've disconnected everything including the fans to rule out a shorted fan header pin, i've removed the board from the case to rule out shorting on the case, removed all but 1 ram stick, put another brand of ram stick in, and nothing changes at all.

Only thing I can verify is that with the cpu removed, it does register that change with the red light around the memory slots, which goes away with the cpu seated, so I guess at the very least it registers that a cpu is there or not. I looked at the bottom of the cpu, doesn't seem to have any bent pins or anything....

I have no other AM4 cpu to test so I'm wondering if anybody can tell if its the motherboard or cpu to blame here before I go out and dump some more money into a cheap AM4 cpu to test?

Thanks!

[rbmorse]

Had the same thing happen with my xHair VIII/3700x.

Power off, pull the plug then press and hold the CMOS reset button on the rear panel for about 5 seconds. I had to do that twice, then it came right up like it was supposed to.

[blppt]

rbmorse wrote:
Had the same thing happen with my xHair VIII/3700x.

Power off, pull the plug then press and hold the CMOS reset button on the rear panel for about 5 seconds. I had to do that twice, then it came right up like it was supposed to.

Tried that, didn't work---i also went out and bought a cheap 3200G to test and it wouldn't power up with that either. Think the mobo is a dud, probably first time thats happened to me since like the year 2000, lol.

Now running the 3900x in a cheaper replacement TUF X570, worked right out of the box.

Thanks for the help, though!

[RedSector73]

case on/off button maybe dodgy (check it or manually bridge - for a fraction of second ) or may have missed the right pins for the connection. You could try using the reset button for on/off to rule that out, never seen two dodgy buttons on one case but you never know !

[blppt]

Yeah, I pretty much ruled that out in the beginning---i stripped down the connections (only the 3 power connectors and cpu fan header connected and of course the vid card) and took the board out of the case to rule out a grounding issue, and used the start button on the board itself, no dice.

I think its just a dud---the TUF i'm using now seems fine and worked with zero issues OOB. But thanks for the help!

[DocJekl]

blppt wrote:
I'm trying to figure out whether the motherboard or the cpu is the culprit here---using a 3900x, properly seated, and we get the multicolored LEDs and "Start" button illuminates, but neither the start button nor the front panel connected power switch (confirmed properly seated) does anything whatsoever---no movement of any of the fans, no code appears on the 2 digit readout. I've disconnected everything including the fans to rule out a shorted fan header pin, i've removed the board from the case to rule out shorting on the case, removed all but 1 ram stick, put another brand of ram stick in, and nothing changes at all.

Only thing I can verify is that with the cpu removed, it does register that change with the red light around the memory slots, which goes away with the cpu seated, so I guess at the very least it registers that a cpu is there or not. I looked at the bottom of the cpu, doesn't seem to have any bent pins or anything....

I have no other AM4 cpu to test so I'm wondering if anybody can tell if its the motherboard or cpu to blame here before I go out and dump some more money into a cheap AM4 cpu to test?

Thanks!

I had very similar behavior with my out-of-the-box Crosshair VIII Dark Hero, and the only way to get to post was after I unplugged everything except for the power, AIO, and one stick of RAM; but the problem was being caused by plugging in the case's USB-C 3.2 Gen 2 front panel connector onto the motherboard. I flipped the front panel USB-C connector 180 degrees and the board stopped going unresponsive again. In my case the mobo start button was lit, and pressing it would apply power and start moving fans for 1 second, and then everything turned off without a post code.

So, I didn't want to tempt fate and try to figure out why the connector isn't reversible, and whether the issue lies in the new ASUS mobo or new case (Fractal Meshigy 2). I have 2 weeks to return to test the issue, if this behavior hasn't been seen before, or is uncommon. The front panel USB-C works fine, board runs fine.

But, I wanted to post this solution in case somebody else finds this rare thread due to a similar problem and doesn't think to flip the USB-C front panel connector. I thought this one was okay being plugged in either way. I don't think that I damaged the connector on the 2 week old case, but I did have an ASRock Taichi Razer Edition motherboard installed in it for about two weeks. It's weird that the Dark Hero acted like DOA tho.
Â*

[Bruce82hki]

DocJekl wrote:
I had very similar behavior with my out-of-the-box Crosshair VIII Dark Hero, and the only way to get to post was after I unplugged everything except for the power, AIO, and one stick of RAM; but the problem was being caused by plugging in the case's USB-C 3.2 Gen 2 front panel connector onto the motherboard. I flipped the front panel USB-C connector 180 degrees and the board stopped going unresponsive again. In my case the mobo start button was lit, and pressing it would apply power and start moving fans for 1 second, and then everything turned off without a post code.

So, I didn't want to tempt fate and try to figure out why the connector isn't reversible, and whether the issue lies in the new ASUS mobo or new case (Fractal Meshigy 2). I have 2 weeks to return to test the issue, if this behavior hasn't been seen before, or is uncommon. The front panel USB-C works fine, board runs fine.

But, I wanted to post this solution in case somebody else finds this rare thread due to a similar problem and doesn't think to flip the USB-C front panel connector. I thought this one was okay being plugged in either way. I don't think that I damaged the connector on the 2 week old case, but I did have an ASRock Taichi Razer Edition motherboard installed in it for about two weeks. It's weird that the Dark Hero acted like DOA tho.
Â*

Did this fix issue with your dark hero? Â*Experiencing about same problems like every 5th-10th wont startup wont power up?
Thanks Â*