PRO B660M-A DDR4 doesn't recognize CPU

jeroenn

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EZ debug LED indicator shows a constant, not blinking, red light next to CPU.

Everything is new out of the box and has not been tested on a different setup except for the graphics card and RAM, both have been tested and work on a different setup.
board: PRO B660M-A DDR4,
CPU: Intel Core i5-12400F
RAM: Corsair DDR4 Vengeance LPX 2x8GB 3200MHz C16 1.35v CMK16GX4M2E3200C16
VGA: Nvidia GeForce GTX 1660 SUPER
HDD/SSD: M.2 NVMe Samsung 980 500GB
COOLER: stock Intel Core i5-12400F cooler
PSU: be quiet! System Power 9 600W

When starting my computer the case powers on including all the fans, CPU stock cooler fan, GPU fan and RGB. The motherboard EZ debug LED indicator shows a red light next to CPU. The computer stays running for 10 seconds before rebooting on its own with the same problem. I have tried every combination of plugging in the CPU power cable into the correct slot, with both the 4 pins connected and with only just one 4 pin connected. Switching the RAM around in different slots and using only one or both ram sticks gives the same result. The RAM works in a different setup and im confident they're seated correctly. I don't notice any bent pins on the CPU socket.
My question is if my brand new out of the box motherboard is already running the updated BIOS version to support/recognize my Intel Core i5-12400F or if I need to M-flash the bios first. And if it is already running the correct BIOS version what else might be causing the problem. Also I've come across atleast 2 different people with the exact same mobo, cpu and ram setup that are experiencing the same problem, could this be a compatibility issue?
 

citay

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The 600-series boards came out with/for the 12th series CPUs, so proper CPU support in the BIOS is not in question, this can't be it.
Where did you come across the others with the same problem on the same board?
Can you test with a different PSU, just to exclude this as well? Also take out the M.2 SSD for now, one less factor in the equasion.
 

jeroenn

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I swapped out the PSU for a different one that works on another setup and took out the M.2 SSD and got the same error. Testing it with a different graphics card also resulted in the same error.
This other PSU only has one 4-pin atx 12v power connector but it did fit into one part of the 8-pin CPU slot.

These two have very similar problems to mine with almost identical board, ram and cpu.
https://www.reddit.com/r/buildapc/comments/uv7ifg
Should I ask for a replacement board and CPU? Or do you think it is most likely a faulty board or something else?
 

citay

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The other PSU with 4-pin only must be quite old, nowadays they should always have an 8-pin EPS12V plug for the CPU. So i don't know if that can be called a conclusive test of ruling out the PSU.
Which was that other PSU you tested with, and how old is it?

As for replacing things, never RMA two things at once. We have to somehow determine if the board or CPU is more likely. But it's just one of them, not both.

Yes, i remember that second thread now. Go through the advice i gave there, especially checking the pins in the socket, those can bend so easily.
 

jeroenn

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I'd guess the other PSU I tested with is about 10 years old, it also doesnt have a PCIe 8-pin but has a 6-pin. That PSU runs a P8B75-M LX bord, Intel Core i5-3470S CPU @ 2.90GHz and Nvidia geforce gtx 660 ti.

That second thread is the reason why I checked the CPU socket pins before posting here and it looked completely fine to me, similar to the picture posted in that thread.
You suggested trying to turn it on on a wooden table in that other thread. Will the setup run without all the case cables attached to the board and is it safe to, for example, plug in the 24 pin atx power connector while the board isnt secured to the case with screws? Plugging in that 24pin connector required a decent amount of force.
 

citay

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Just support the board a bit from behind when you plug in the cables. It's completely safe. To start the board, put a screwdriver on the two pins for the power button. The power button does exactly the same thing, it shorts the pins and that gives the "power on/off" signal.

Yeah, the 4-pin-only for the CPU was a dead giveaway. I'm afraid a 10-year-old PSU is not a good confirmation either way. PSUs age, and are often one of the first things to cause problems in a PC, read my Guide: How to find a good PSU. So if you wanted to really rule out the PSU, you'd have to use a known good and not too old one, or a new one. That other PSU is probably ripe for replacement, unless it was a really good model with similarly good electrolytic capacitor models (those are the main components that get weaker with age). If you tell me the exact model, i can look it up. If it's a cheaper model, then yeah, its best days will probably be behind it.
 

jeroenn

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Thank you for your help btw.

Just tried it without the case and on a wooden surface and the CPU led is still on.

The other PSU I used for testing is a Channel Well Technology DSAII5005-G 500W I think? Thats whats indicated next to model, although googling it only shows similar PSUs.
You'd think a brand new be quiet! system power 9 PSU wouldn't cause the problem, although the mobo and cpu are also new.
It feels like I've exhausted alot of options im not sure whats left.
 

citay

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I'm always glad to help.

Ah, a CWT, the DSAII is a very low-budget design. That one will definitely be on wobbly legs by now. The capacitors lose their properties and you're stressing the attached hardware more and more.
Therefore that test was not very conclusive.

About your be quiet! PSU, you will see in my PSU thread that i like that brand myself. But since everything is untested, you first start from the component that is easiest to test. I mean, you will agree that borrowing a decent, not too old PSU (or otherwise acquiring one) is easier than testing a different CPU or board. Maybe you even want to get a new PSU for your second PC, or get a slightly better one for this main PC and use this one for the second PC.

Even the best PSUs can sometimes (rarely) have some fault. Just because the PSU model seems ok, we can never fully rule it out unless the PC has been tested with a different known good or new PSU. Unless you want to go straight to the next thing: Either testing a different CPU in this board, or this CPU in a different 600-series board. Or if you can't do that, either trust the board (since it says "CPU"), or trust the instinct that the board is still more likely to have a fault than the CPU.
 

jeroenn

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Is it possible an old PSU like the DSAII could damage parts?

Would my CPU run with only one 4-pin connected into the 8-pin CPU power slot?
What if I use the new be quiet! power 9 PSU on my old PC that runs a P8B75-M LX bord, Intel Core i5-3470S CPU @ 2.90GHz and Nvidia geforce gtx 660 ti. If it works would that increase the likelihood my PSU is not at fault?

I don't think testing a completely different CPU or board is going to be possible so I might just RMA one or the other after confirming its not the PSU.
 

citay

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Such an old PSU can usually cause things like silent data corruption and crashes, it's rare that it outright damages something. You are stressing the attached hardware more if the filtering capacitors in the PSU don't do their job very well anymore. But it's not an immediate risk in that regard.

Running the old system with the new PSU would indeed increase that likelihood you speak of, however, we want to get a definitive answer. And for that, you would need to test the new system with a different known good or new PSU.

As for CPU or board, contact @lowdominio154d02de to see if he has any news, he's the user from the thread you linked. To me, the board seems more likely, but that can't be guaranteed.
 

jeroenn

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Returned my board and they told me they couldn't get it to post either so I got a replacement. The replacement board arrived today and I'm typing this from my new computer! So it seems it was the result of a faulty board.

Thank you again btw for guiding me through this and I learned alot for when I build another PC in the future.
 

jeroenn

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I'm not sure if I should create another thread but I've been having trouble with my case fans.

The green graph shows the problem. My case fans audibly speed up and slow down considerably consistantly every 2 seconds or so. Going from 1600rpm to 800rpm and back repeatedly.
pc fans2.png

Same specs as posted in my first message. Using an old sharkoon tg4 case which has 3 rgb led 120mm front fans and one 120mm rear fan.
The rear fan is plugged into System 1 fan header with a 3pin plug. The 3 front fans are plugged into PUMP1 with a 3pin plug.

I've read your "setup fan curve in BIOS" guide and switched the fan settings in BIOS from PWM to DC and enabling smart fan with a similar ascending dominant curve.
pc fans3.png

pc fans4.png

pc fans5.png

Weird how only the system 1 fan shows voltage use and the voltage also jumps down from 7.20V to around 4.50V randomly in that chart.
 

jeroenn

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Updated the BIOS and changed back all the settings to what they were in the previous post.

The BIOS update seems to have completely fixed the problem on a 15%+, non idle, CPU workload. But when it's idle, OCCT still shows that the system 1 fan is jumping around. Although this is completely inaudible and I can't tell by feeling the airflow at the back or looking at the fan spinning around in real time. Maybe I should increase the SYS Fan1 step up time from 0.1s to 1.0s but I don't see why as I don't notice the problem at all anymore.
pc fans7.png

Thank you for the help again.
 
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