[SOLVED] Asus Prime Z490-P with i9 10900F: No Power On

[imperfect]

Hi all - I'm wondering whether anyone might have any insights into my build that doesn't power on.

In an overly optimistic manner I assembled the whole thing into the case only to find it non-responsive to the power button, but I've taken everything out again and tried to breadboard it.

The components still included are:

CPU: Intel Core i9 10900F 10-Core LGA 1200 2.80GHz CPU Processor
Motherboard: ASUS PRIME Z490-P Intel LGA 1200 ATX Motherboard
PSU: Cooler Master MasterWatt 750W 80+ Bronze Semi-modular Power Supply
RAM: Corsair Vengeance LPX 32GB (2x 16GB) DDR4 3200MHz Memory [one stick for testing]

When I switch on the PSU, the motherboard illuminates with an orange LED - think it's just for effect, not an indicator light.

When I attempt to power on by connecting the power switch pins with a screwdriver, I hear a tiny creak or click from the PSU, but then nothing happens: no PSU fan, motherboard fan or anything.

I've tried it with no RAM, and with each of the two RAM sticks individually (in the RAM slot recommended for running a single stick in the manual as pictured).
I've tried resetting the CMOS.

One point of confusion I have is around the CPU power. The motherboard manual indicates that connecting the 4 pin in addition to the 8 pin is optional, but ASUS' troubleshooting guide does indicate that I should try populating both the 4 and 8 pin if the PC won't power on:

[Motherboard] Troubleshooting - No Power/No Boot/No Display | Official Support | ASUS USA

However everything else I've read seems to suggest that this extra power is unlikely to be needed, since I'm not doing any overclocking and my graphics card isn't even plugged in for this test. My PSU only has one 8-pin CPU power, so I'd have to buy another one to see whether having the P4 plugged in solves this; not sure whether that is a good or foolish first thing to try. (I don't have access to any other components to test with without buying them.)

If anyone has any general advice on this - or happens to have set up the same or similar components and can tell me definitively if I do/don;t need the additional P4 - it would be much appreciated. Thanks!

 

[Darkbreeze]

I'd unplug those EPS connectors from the EPS/CPU sockets and check to see that they are seating correctly AND fully. Looking at your picture, it almost looks like one of them is offset and not seated the same as the other. Keep in mind, these sockets are KEYED and both connectors are NOT the same, so they MUST be plugged in in a specific orientation in order to actually seat correctly. We HAVE seen people force them in the wrong spot before though, so that's always possible if you've done so.

Just something to check because they don't look to me in the pics like they are both sitting the same.

If that is all good, and I WOULD absolutely remove and reinstall both of the EPS connectors AND the 24 pin ATX connector, just to be sure they are fully seated and there are no problems with any of the terminals or socket pins in either of the connectors, then I'd recommend that you pull the CPU and make damn sure there are no bent pins on the motherboard. Because this really sounds like there are bent pins on the motherboard. You may need magnification like a magnifying glass or high powered reading glasses to SEE minor deviations to the pin structure in the CPU socket pin bed. If there are no bent pins, then I'm going to assume that it's the fact that:

YOU HAVE NO GRAPHICS CARD INSTALLED AND THAT CPU HAS NO INTEGRATED GRAPHICS.

If you ARE using a graphics card and are connecting your display cable to it, and it just isn't shown in your pictures here, then I'd say it's simply a bad motherboard.

 

[imperfect]

Thanks for the tips!

Just something to check because they don't look to me in the pics like they are both sitting the same.

Tried unplugging and replugging them. (But to be honest, have done that a bunch of times prior to posting.)

YOU HAVE NO GRAPHICS CARD INSTALLED AND THAT CPU HAS NO INTEGRATED GRAPHICS.

Right, but I'd expect for the fans to come on in response to the power without my graphics card installed, wouldn't I? Or does that vary by motherboard?

Unfortunately in this case the behaviour with the graphics card in with its power attached is the same.

I'd recommend that you pull the CPU and make damn sure there are no bent pins on the motherboard

Right-o. I was kind of trying to avoid getting into getting into reapplying themal paste and all that stuff but I guess that ship has sailed.

So you reckon there's zero chance I need the P4 connected right? It threw me that the Asus troubleshooting says "Some motherboard may contain 8-pin EATX12V_1, 4-pin EATX12V_2 and 24-pin EATXPWR, we suggest to connect all three connectors to the power supply."

 

[Darkbreeze]

Ok, so if it does it with a graphics card properly installed, then obviously, that isn't the problem.

There is always a chance you might need to have the other EPS connector plugged in, especially on that PSU. That's not a fantastic model to begin with. If you had any other CPU from that generation, with a lower core count, I'd discount the possibility, and it's STILL unlikely because generally you only need that additional EPS connector for extreme overclocking, BUT I have seen a couple of 3950x and 9900k systems that would not POST without all 3 4 pin connections attached, so it might be something relevant to the board model, or just a weak PSU. IDK for sure.

I still suspect that it's a bent pin on the motherboard.

 

[Nemesia]

You're very courageous to plug your GPU with that cheap adapter.

With a system like that get a decent PSU model.

 

[imperfect]

Thanks both. I'll probably try replacing the PSU first then, if it's too rubbish anyway. Then if that doesn't work check out the motherboard pins and potentially return it. Sigh, it took like a month to get here by air.

I'll try to pick replacements that are available locally (Western Australia) that I can physically pick up, which is mostly PLE computers. What do you think of this one:
https://www.ple.com.au/Products/627647/Corsair-HX750-750W-80PLUS-Platinum-Modular-Power-Supply

 

[Why_Me]

Thanks both. I'll probably try replacing the PSU first then, if it's too rubbish anyway. Then if that doesn't work check out the motherboard pins and potentially return it. Sigh, it took like a month to get here by air.

I'll try to pick replacements that are available locally (Western Australia) that I can physically pick up, which is mostly PLE computers. What do you think of this one:
https://www.ple.com.au/Products/627647/Corsair-HX750-750W-80PLUS-Platinum-Modular-Power-Supply

That's a super solid psu.

If you want to save a few dollars then here's another one to consider.

https://www.ple.com.au/Products/639640/Corsair-RM750-750W-80Plus-Gold-Modular-Power-Supply

 

[Darkbreeze]

Yes, that is a VERY excellent power supply (The HX). Exactly the kind of unit I'd recommend you should be looking at. And then you can get rid of the cheap adapters that might be half your problem anyhow.

The RM is ok, but not for this build really. If you're going to go with something lower than the HX from Corsair, I'd stick to the RMx or RMi units, not the regular RM unit. There are significant differences.

 

[imperfect]

Happy ending: swapping out the PSU with the HX750 solved the problem. Hooray.

For the record/anyone else coming to this with the same problem:

• As soon as the PSU was swapped, powering on the motherboard outside of the case made the CPU and PSU fans spin (i.e. graphics card being in place wasn't necessary to observe this response).
• I have connected all three CPU power connectors to the motherboard on the new PSU. I have not tried it with just two and don't want to experiment now everything is working!
• New PSU does not need those adapters everyone was worried about to plug into the graphics card ("ZOTAC GAMING GeForce RTX3070 Twin Edge OC").

So, I should not have blindly trusted pcpartpicker's compatability thing (and apparently didn't do enough research on PSUs...), because is appears the "Coolermaster MasterWatt 750W 80+ Bronze Semi-modular Power Supply" simply doesn't work with "Intel Core i9 10900F 10-Core LGA 1200 2.80GHz CPU Processor" and "ASUS PRIME Z490-P Intel LGA 1200 ATX Motherboard".

Thanks again for the help!

 

[Darkbreeze]

appears the "Coolermaster MasterWatt 750W 80+ Bronze Semi-modular Power Supply" simply doesn't work with "Intel Core i9 10900F 10-Core LGA 1200 2.80GHz CPU Processor" and "ASUS PRIME Z490-P Intel LGA 1200 ATX Motherboard".

The bottom line, for me, is that MOST Cooler Master power supplies are just not very good. Period. Even ones that have seemingly done well in reviews, seem to have a tendency to not do so well when it's an actual retail sample. It would not come as any shock to me to find that Cooler master sends out cherry picked PSU samples to reviewers, because, oh yeah, we already know they do. And the Masterwatt products are definitely not among those few very good models that Seasonic has built for Cooler master here and there in the past.

Not sure without going and taking a look to see who the OEM is for Cooler master on that specific PSU model, but regardless, I've seen enough people with problems that had those units to simply recommend avoiding them when there are so many other good quality units on the market that are near enough in price to not make it worth the trade off.

Glad it was just the PSU. I figured it probably was. It was either going to be a bent pin or a PSU issue, almost assuredly.