Question Red CPU LED on and no video on brand new MSI MAG B550 TOMAHAWK

May 4, 2021
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Hi,
I just completed a brand new build as per specs below and the Red CPU LED on the motherboard is on (the other LEDs are off) and there is no image on the display. Also there is no beep/audio either when trying to boot. Can somebody help please?

The bequiet case I am using does not have the classic 2-pins audio connector. And the motherboard does not have the two-digit display for the Q codes. How can I get specific codes?

I just "plugged in all the parts". Is there something else that needs to be done with that motherboard/processor perhaps before booting it for the first time? They are all brand new parts.

I tried the following:
  • tried using an old PCI graphic card because I read that it could be because the Ryzen does not have graphic support and while waiting for it I a couple of 5 years old PCI graphic cards. I assume any old-ish PCI graphic card would work, correct?
  • tried with a single RAM slot placed in DMMA-2 (as suggested in the manual)
  • CPU pins are all good (always been extremely careful when unpacking and installing the CPU)
  • the P8 connector for CPU power is plugged in
But still no video and the red CPU light on the motherboard is on.
  • CPU: AMD Ryzen 9 3900X 3.8 GHz 12-Core Processor
  • CPU Cooler: The one that comes with the CPU for now then pending performance then switch to liquid cooled on (see question at the bottom)
  • Storage: 2 x Western Digital SN750 1 TB M.2-2280 NVME Solid State Drive BOTH mounted on the two M.2 slots
  • Case: be quiet! Silent Base 601 ATX Mid Tower Case
  • Motherboard | MSI MAG B550 TOMAHAWK ATX AM4 Motherboard
  • Memory | PNY XLR8 32 GB (2 x 16 GB) DDR4-3200 CL16 Memory
  • Power Supply: be quiet! Straight Power 11 - 750W
Waiting for the Video Card: Asus GeForce GTX 1650 G6 4 GB Phoenix OC

Thank you as always :)
 
Last edited:

PC Tailor

Judicious
Ambassador
What is the rest of your system spec?
  • Memory make/model?
  • PSU make and model?
Have you checked the CPU for any contamination or bent pins?

Go through everything here first: "No POST", "system won't boot", and "no video output" troubleshooting checklist | Tom's Hardware Forum (tomshardware.com) even if you've done them before, as this guide really does cover the majority of issues.

I read that it could be because the Ryzen does not have graphic support and while waiting for the I tried different video cards (a couple of 5 years old PCI graphic cards). I assume any old-ish PCI graphic card would work, correct?
That would stop the system from booting yes. PC needs graphical output before it can boot. But it would usually cause a VGA error, not a CPU one.
 
May 4, 2021
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Thank you PC Tailor!! :)

I updated the OP with the PSU and Memory specs.

All CPU pins are as they should. And just went through the list in the link you suggested (thank you for that!) but no boot yet. Anything else to try?

Does the power switch have polarity? It doesn't show any on the bequiet manual but it does show polarity in the motherboard manual. I always thought that the front panel switch is a standard push-button switch (i.e. mechanical without polarity), but maybe the motherboard requires a logic level type output where there is polarity? A bit strange but thought worth asking.

Thank you as always!! :)
 
May 4, 2021
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At the moment I have the CPU cooler fan connected to the motherboard but the cooler is NOT mounted on top of the CPU (because I want to make sure it all works correctly before attaching the cooler). Does that motherboard sense that the cooler in not mechanically on top of the CPU? I could not see any contacts/sensors...
 
May 4, 2021
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It is a Firepro W5000. I just checked and it is a PCIe. I don't think the old PCI would insert, correct?

But it is not the VGA led that comes up but the CPU led. Can the graphic card cause the CPU led to come one?

The HD audio of the case is connected but there is no beep/audio when switching it on. Can that indicate something?

The bequiet case does not have the classic 2-pins audio connector. And the motherboard does not have the two-digit display for the Q codes. How can I get specific codes?
 
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May 4, 2021
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Hi,
a brand new MSI MAG B550 TOMAHAWK with brand new Ryzen 9 3900X 3.8 GHz 12-Core wasn't booting/POSTing. So I reset the BIOS.

Is there a way to flash the BIOS with the latest version when the motherboard is not bootping/POSTing? If so, how?


Thank you :)
 

avg9956

Commendable
Apr 7, 2019
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You can flash boards without a CPU and RAM installed, this is known as BIOS Flashback (which is present in modern boards). Note that older motherboards cannot do this feature.

View: https://www.youtube.com/watch?v=rTBs0-gTJRI


Luckily there's a video of your exact board model on how to do this

I have done BIOS flashback myself on my MSI X570 Tomahawk board when my Ryzen 9 5900x didn't boot, it went without a hitch. Just make sure you're using USB 2.0 flash drive (BIOS can be quite picky), format it to NTFS file system and rename the file BIOS file appropriately. On MSI Boards, there is a dedicated USB 2.0 just for BIOS Flashback, this is where you plug the USB 2.0 in.
 
Reactions: Star2222
May 4, 2021
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Hi,
the MSI MAG B550 TOMAHAWK seem to have just 4 debug LEDs CPU/VGA/MEM/BOOT. Is there any way to get more precise debug infos like specific codes (by get them to flash a sequence or something similar)?

Thank you :)
 
May 4, 2021
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Thank you both, :)
The motherboard has the 10-pins HD Audio connector (9-pins to be precise, 1 missing for keying) as well as both the classic 2-pins buzzer connector and 2-pins speaker connector.

I connected only the "HD audio" 10 pins connector to the Be Quiet Pure Base 500DX because it does not have either one of the classic 2-pins buzzer and speaker connectors. I assume it is the same? Or not?

i.e. would the diagnostic/POST beeps/sound be present on that connector as well?


If not (i.e. the POST sound comes out only from the 2-pins speaker or buzzer connectors) how can I get POST diagnostics sound?

Thank you
 
May 4, 2021
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Only temporarily, the system booted and it was working for few minutes then started again. I just tried re-flashing the BIOS and now it does not seem to come out from BIOS-Flashing mode. Has been sitting there for 20 minutes.

Any other suggestions?

Thank you :)
 
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May 4, 2021
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Hi,
I cannot find the Asus G6 4 GB Phoenix OC Video Card anywhere here in the UK.

1) can you suggest an alternative that is similar in performance (used for CAD and engineering work NOT for videogames)?

2) while I am trying to get this new system up and running, I am trying these two graphic cards I have: AMD FirePro W600 and also FirePro W5000
Is there any reason for them not to be compatible or not work with a MSI MAG B550 TOMAHAWK ATX AM4 Motherboard?

Thank you :)
 
May 4, 2021
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Thank you COLGeek,

I tried only the W5000 because to try the W600 would need to take it off the system I am currently running.

I have opened separate threads because in the past on other forums when I tried posting questions that were quite different from the OP, despite being related to the OP, I've been asked to post them as new threads.

Thank you
 
May 4, 2021
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Thank you, :)
but how do I do that if to enter the bios I need the monitor because the card itself needs setting up like you suggested? It's a catch-22 situation, isn't it? Or are there other ways?

Thank you
 

Vic 40

Titan
Ambassador
You are right, no other gpu you can maybe lend to test with?

What i'm personally looking at is that ram you have, not on the supported list, although it probably uses chips that are common maybe soemthing that doesn't work out right with the system more since it did boot after the bios update. Could return it and try another brand see if that helps.

Other thing might just that the cpu you got is really faulty, again can return/rma it and test with another one. The motherboard may be the same story. hard to figure out without replacing parts.
 

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