MPG Z490 Gaming Plus no longer powers up

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Oct 22, 2021
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Hi. I have a MPG Z490 Gaming Plus motherboard that's worked fine since purchase on 4/11/2021 but suddenly since yesterday no longer powers up. The power supply (Corsair CX750F RGB, 750 Watt, 80 PLUS) appears to be working (all ATX connector voltages read as expected, when I short PS_ON# to COM), and I read 3.5V across the motherboard jumper terminals where my case's power button connects, but there is no visible response from the board when I connect and press the power button to power it up. No LEDs on the motherboard light, and the fan does not light up or spin. Are there suggested next diagnostic steps I can try? Thanks.
MPGZ490.jpeg
 
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citay

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The problem with PSUs is, it is not a simple case of "on = works" and "off = doesn't work" when you short it with the jumper trick. It's a complex piece of electronics, there can be a number of things wrong with the quality of the output voltages, and for many of them to manifest, there has to be some load on the PSU.

The only way you can reliably exclude it as the culprit at home is testing the same system with a different PSU. Problem stays the same -> wasn't the PSU, problem disappears -> was the PSU.

This is the first thing i would do, because it's also one of the easiest. Maybe you can borrow another PSU somewhere. As for the power switch, try using the reset switch as a power switch, if that doesn't work either, it's probably not related.

Next thing would be to try with the board on a non-conductive surface like a wooden table.
 
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The problem with PSUs is, it is not a simple case of "on = works" and "off = doesn't work" when you short it with the jumper trick. It's a complex piece of electronics, there can be a number of things wrong with the quality of the output voltages, and for many of them to manifest, there has to be some load on the PSU.

The only way you can reliably exclude it as the culprit at home is testing the same system with a different PSU. Problem stays the same -> wasn't the PSU, problem disappears -> was the PSU.

This is the first thing i would do, because it's also one of the easiest. Maybe you can borrow another PSU somewhere. As for the power switch, try using the reset switch as a power switch, if that doesn't work either, it's probably not related.

Next thing would be to try with the board on a non-conductive surface like a wooden table.
Thank you. You're right, it could still be the power supply, and it would actually be great if it's that simple. I'll acquire another and give that a try next. Much appreciate the thought and suggestion!
 
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Had a local PC repair shop take a look. The Corsair CX750F RGB power supply passed their diagnostics, and swapping in a different, known good power supply unfortunately did not produce a different result. No obvious signs of any physical damage, but the motherboard shows no signs of life when we connect power and attempt to power it up. Their best guess is some kind of failure on the motherboard itself.
 

citay

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Ok, at least you have certainty about the PSU now. Unless they already did that in the shop, i would take out the board and try it on a non-conductive surface like a wooden table.
 
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Thanks. Tried that but unfortunately still no visible response from the motherboard. (CPU and RAM removed now to prepare it for shipping but I'd expect we'd still see basic power indication LEDs
MB.jpg
.)
 
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Where does one find the "CHK" code that product registration wants? I don't see anything like the sticker pictured in the page 3 registration instructions.
 

citay

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No problem. Even though i don't like it when things can't be solved other than with an RMA. But when something's dead and you even had a repair shop try their luck, that's how it has to go.
 
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