Question No display with new Ryzen 7 5700G and Asus Prime B450M-A II

Mawla

Commendable
May 21, 2021
51
0
1,530
My new Ryzen 7 5700G and Asus Prime B450M-A II were delivered today but I can't get them to POST. There's no display at all.
All voltage outputs from the PSU are normal. The CPU fan spins, the RAM LEDs light up.
USB keyboard and mouse do not light up.

Asus says the mobo is compatible with a 5700G since BIOS 2409 but I have no way of checking the version since there's no display.
If the BIOS is older than the required version, is it normal to have no display at all?
If the answer is yes, is there anything I can do other than finding an older CPU to update the BIOS with?
I have not yet used the BIOS flashback button.

Other parts:
Memory: ADATA XPG Spectrix 2x8GB 3200 RGB
PSU: XPG Pylon 550W

Nothing else is fitted/installed. No HDD/SSD, no discrete graphics card.
I've tried with a single stick of RAM on different slots. I've cleared the CMOS. No difference.
 
Aug 3, 2022
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Oops missed that. Does the product data on the box by any chance say the manufacture date and then you could assume that the BIOS is up to at least that date? If you could get a hold of an older Ryzen and see if it works would be a good test and then update the BIOS to support the 5700G if it is an older BIOS.
 

Mawla

Commendable
May 21, 2021
51
0
1,530
The box says the motherboard was manufactured in Sep 2020. BIOS v2409 date is Dec 2020. So the BIOS version must be older than that required to support the CPU.

I wish someone would answer the question I asked the first time: If the BIOS version is older than that required to support a given CPU, is it normal to have no display at all?
 
Aug 3, 2022
40
16
45
I didn't answer that question because I have never seen it but I would definitely say an un-supported CPU would cause that because the BIOS does not know what to do with the CPU and onboard video so you get a blank screen, no post
 

Mawla

Commendable
May 21, 2021
51
0
1,530
So the only thing to do would be to flash the BIOS with a supported CPU.
Since the technologies are close enough to support the 5700G with a BIOS update, I was wondering if it would work to some extent with the old BIOS, enough at least to enable flashing the BIOS.

Oh well, unless someone else comes up with a different approach that could help, I guess I'll have to borrow my nephew's Ryzen 5 3400G and flash the BIOS tomorrow. It's past midnight here now.
 
Aug 3, 2022
40
16
45
That would at least tell you your new mobo is good or bad. If it works with your nephew's Ryzen then it really should be as simple as a BIOS update. Best of luck to you. Keep us updated if it works or not
 

DSzymborski

Titan
Moderator
So the only thing to do would be to flash the BIOS with a supported CPU.
Since the technologies are close enough to support the 5700G with a BIOS update, I was wondering if it would work to some extent with the old BIOS, enough at least to enable flashing the BIOS.

Oh well, unless someone else comes up with a different approach that could help, I guess I'll have to borrow my nephew's Ryzen 5 3400G and flash the BIOS tomorrow. It's past midnight here now.

This is the expected behavior. It doesn't matter if they're close; the microcode just isn't there. It's like dialing a phone number and getting a number wrong.
 

Mawla

Commendable
May 21, 2021
51
0
1,530
Thanks for your continued support, guys. I got up late and haven't actually done anything yet. I'm going through the link and sub-links provided by egda23.
I don't want to rush and possibly brick the motherboard. I'm sure you're all aware that many technical instructions and explanations seem crystal clear if you already know the answers, but not so clear if the topic is unfamiliar.
 
Aug 18, 2022
1
0
10
My new Ryzen 7 5700G and Asus Prime B450M-A II were delivered today but I can't get them to POST. There's no display at all.
All voltage outputs from the PSU are normal. The CPU fan spins, the RAM LEDs light up.
USB keyboard and mouse do not light up.

Asus says the mobo is compatible with a 5700G since BIOS 2409 but I have no way of checking the version since there's no display.
If the BIOS is older than the required version, is it normal to have no display at all?
If the answer is yes, is there anything I can do other than finding an older CPU to update the BIOS with?
I have not yet used the BIOS flashback button.

Other parts:
Memory: ADATA XPG Spectrix 2x8GB 3200 RGB
PSU: XPG Pylon 550W

Nothing else is fitted/installed. No HDD/SSD, no discrete graphics card.
I've tried with a single stick of RAM on different slots. I've cleared the CMOS. No difference.

So i actually got this cpu and motherboard today and started building away. I found this thread because i was having the same problem. Now i am not sure what i did but i ended up getting a picture and booting into bios after i did this. I followed the directions on Asus website to flashback using the button and a flash drive on the back of the computer. I kinda just held the button down for 10 seconds and waited for maybe like 5 minutes. after that I noticed that the motherboard lights up orange when its powered. I was messing with the PCI slot as i dont have a GPU installed. I notice that the PCI slow has a moving plastic piece that holds the card was flipped open as if it was waiting for a GPU. ASUS calls it ASUS SafeSlot Core. so by the name i take it that it needs to be in the close position? I am not even sure if thats right. but i am installing windows on my system now. I hope this helps!
 
May 27, 2023
1
0
10
Hello all - long time fan of Tom's Hardware but posting here for the first time.
I have this exact same combo (PRIME B450M-A II and AMD Ryzen 7 5700G) and cannot for the life of me get a video output.

Additional specs:
Ram: Mushkin MSL4U320NF32GX2 (2x32GB)
HD: ADATA Legend 850 LITE M.2 SSD
BIOS: tried both 4002 and 3810 using the Flashback tool

I get the yellow lights and I've tried stripping it down to nothing else plugged in but the memory (admittedly the m.2 ssd) and an HDMI connected monitor (or a DVI connected monitor) - but am getting no video output.

Common issues on this and other threads seem like not previously flashing the bios and dodgy ram. I guess its possible my ram is bad but other than that I'm at a loss.

Any advice?