[SOLVED] Seasonic Focus PX 750 Start-Up Issue

[Gunnerhero]

Hi everyone,

I recently changed my PSU out for the Seasonic Focus and have noticed something strange when it starts up.

On a cold start, the PC will start up for a couple of seconds and then turn off. It will then immediately reboot itself and will start up fine. I can only seem to replicate the issue after turning the PSU off on the rear switch.

I have ran numerous stress test on AIDA64, Cinebench and Heaven benchmarks and it has completed them fine once up and running.

I have checked that all of the cables have been plugged in correctly and have only used the cables provided with the PSU. My old PSU was not modular. I have made sure that they have been correctly inserted into the PSU itself. I have read on the Seasonic troubleshooting site that it may be the motherboards anti-surge protection kicking in?

My system currently:
Mobo: Asus ROG X470F
CPU: AMD 2700X
Graphics: Gigabyte 1060 6GB (Upgrading to Asus TUF 3080 OC 10GB)
Ram: Corsair Vengeance 2 X 8 GB
PSU: Seasonic Focus PX 750

Any help would be greatly appreciated.

Cheers,

Tom.

 

[Barty1884]

If you shut down the system, does it happen? Or is it only once the PSU has been switched off?

If it's only after the PSU on/off, it's the motherboard. Not sure as to the rationale, but I've had numerous ASUS motherboards (including the Z390 Maximums XI I have now), and they all behave in the same way.

If it happens even after a simple shut-down (or restart), then it's something different.

 

[Gunnerhero]

If you shut down the system, does it happen? Or is it only once the PSU has been switched off?

If it's only after the PSU on/off, it's the motherboard. Not sure as to the rationale, but I've had numerous ASUS motherboards (including the Z390 Maximums XI I have now), and they all behave in the same way.

If it happens even after a simple shut-down (or restart), then it's something different.

Hi again Barty,

Thanks for your help on my last post, I went and bought the Seasonic in the end, now i'm just waiting for the 3080 to be delivered now...

My system will shutdown fine and will start straight back up again perfectly once I hit the power button. It will start up fine after any period of time as long as I don't switch the PSU off.

The issue happens when I flip the switch on the back of the PSU, discharge the system so that all of the internal LEDs etc. turn off (usually after 20 seconds or so). I then flip the PSU back on and hit the power button, it will start up for a couple of seconds and then turn off, as if there has been a power cut. It will then restart in the next couple of seconds and boot up fine with no BIOS error messages, which I would imagine would come up if the Asus power protection kicked in?

My PC is currently plugged into an extension lead so that may be causing the issue. I'll try plugging it into the wall directly to see if that makes a difference.

 

[Barty1884]

Yep, that behaves exactly as my motherboard does (and quite a few ASUS boards prior all have)

It's not an extension cord or anything, it's by design from ASUS, for whatever reason.

 

[Juular]

Not sure as to the rationale

Memory training.

 

[Barty1884]

Memory training.

That's what I thought.... The first time or two I experienced it.
But even with a brief outright power-loss? As in, I can flip the switch on my PSU back & forth and it does it instantly..... Not even long enough to drain caps or anything.

 

[Juular]

That's what I thought.... The first time or two I experienced it.
But even with a brief outright power-loss? As in, I can flip the switch on my PSU back & forth and it does it instantly..... Not even long enough to drain caps or anything.

It should do that on every POST sequence, nothing to do with caps draining. Well, perhaps only after a hard shutdown like one after flicking the switch, not sure.