(SOLVED)No post - Red Light blinking 3 times on MOBO

LoF

Standard Member
Hello,
I have bought a new case for my PC and have installed the motherboard along with all my original components. The PC worked without any issues previously. After installing all of the components in the new case I attempted to boot the pc however a red light near the IO shield blinks 3 times and nothing happens, i have attempted to start the PC several times using the power button of the case has been plugged into the motherboard and attempted to start it using a screw driver and touching the two pins, all of these attempts failed with the same Red light blinking 3 times. I have also tried to do a CMOS reset by taking out the small battery out of the motherboard and waiting 5-10 minutes, I have did this three times and the same red light shows. I have tried to boot the pc by disconnecting all of the Fans which were plugged into the motherboard but no result. I have also tested my power supply unit using the paper clip test which turns out that the power supply works as intended. Here is a list of my components:
  • CPU - Ryzen 2700x
  • GPU - RTX 2070
  • MOBO - MSI B450 Carbon AC Gaming Pro
  • RAM - 16GB Corsair Vengeance RGB Pro
  • PSU - Cooler Master 700W
  • CPU Liquid Cooler - Cooler Master
Please help, I’ve spent the entire day doing this as I’m a little bit inexperienced since I’ve never built this PC (got it from a friend of mine).

The PSU is nearly 13 years old however the paperclip test shows that it probably works as intende, it worked fine previously so I don’t see any reason why it would suddenly stop.
 

DavidG1

Active Member
I would strip everything back to bare bones, no disk drive, 1 stick of RAM, reset the BIOS (again) by removing the CMOS battery for 10m and try again. If no better try the stick of RAM in an alternative position. If still no better try a different stick of RAM and do the same again.
check the I/O plate isn’t shorting out any of the ports.
remove the motherboard and check the standoff positions aren’t grounding the motherboard and/or any loose screws.
put the motherboard on the motherboard box, remove the front panel connectors, temporarily hook up the bare bones as before and see if you can get a boot by bridging the start up pins.
if no better you will need to take it to a tech where they can swap out with known good components to find the fault.
The paper clip method isn't a reliable way to check for PSU faults, the only real way is to swap out with a known good PSU
HTH
David
 
Last edited:

jimscreechy

Active Member
I would also remove and reseat the CPU and cooler.

The same thing happened to me once when I did a case move. I didn't remove the CPU and cooler because it wasn't necessary, but in the move the CPU somehow became slightly unseated, even though there were no bent pins or any other visible irregularities.

Removing and reseating fixed the issue.
 

LoF

Standard Member
I would strip everything back to bare bones, no disk drive, 1 stick of RAM, reset the BIOS (again) by removing the CMOS battery for 10m and try again. If no better try the stick of RAM in an alternative position. If still no better try a different stick of RAM and do the same again.
check the I/O plate isn’t shorting out any of the ports.
remove the motherboard and check the standoff positions aren’t grounding the motherboard and/or any loose screws.
put the motherboard on the motherboard box, remove the front panel connectors, temporarily hook up the bare bones as before and see if you can get a boot by bridging the start up pins.
if no better you will need to take it to a tech where they can swap out with known good components to find the fault.
The paper clip method isn't a reliable way to check for PSU faults, the only real way is to swap out with a known good PSU
HTH
David
I placed the mobo on a cardboard box, barebones with one ram stick, same issue persists. Red light blinks 3 times and that’s it. Tried the cmos reset again. Looks like I’m going to need to re-insert the cpu as that looks like my final option. Cheers
 

jimscreechy

Active Member
Sorry my poor attempt at humour just backfired there.

Given barebones tends to mean essential components, by 'boneless' I mean striped down to nothing on the motherboard, so no components at all... at any rate just try reseating The CPU but give it a once over with a close eye, just to make sure its fine.

Also do the same for the motherboard, just have a close visual look over all the components and tracks. A stray flake of solder or some other small foreign metal body introduced during the move could easily cause an issue.
 

v2 API

Distinguished Member
Please check and double check your power/power reset/hdd led case connectors to the motherboard.
 

CARLOS

Distinguished Member
Did you connect the 8 pin CPU power connector as well as the 24 pin ?
 

LoF

Standard Member
Please check and double check your power/power reset/hdd led case connectors to the motherboard.
I have, doesn’t work. Now I have my motherboard outside of the case, it’s sat on a cardboard box, still doesn’t post when I bridge the two pins.
 

CARLOS

Distinguished Member
I have, doesn’t work. Now I have my motherboard outside of the case, it’s sat on a cardboard box, still doesn’t post when I bridge the two pins.

Take a photo of the way its set up now outside the case
 

LoF

Standard Member
image.jpg
 

Attachments

  • image.jpg
    image.jpg
    327.8 KB · Views: 29

LoF

Standard Member
No I haven’t flashed it, I don’t have access to another computer atm
Have you flashed the bios at all, via a USB stick?
no I haven’t, I don’t know how to and I don’t have access to another computer, I have ordered new cmos batteries which will come tomorrow
 

CARLOS

Distinguished Member
Everything looks right apart from no graphics card, you are testing it with the graphics card ?
 

CARLOS

Distinguished Member
Good chance it is the power supply and to be honest at 13 years old I wouldn't even consider connecting a PSU of that age to a modern system.
 

LoF

Standard Member
Everything looks right apart from no graphics card, you are testing it with the graphics card ?
This build has an RTX2070 but it is not in at the moment. I am trying to see if the motherboard even works at this point
 

CARLOS

Distinguished Member
This build has an RTX2070 but it is not in at the moment. I am trying to see if the motherboard even works at this point

But it won't work without the GPU installed as the Ryzen has no built in GPU
 

CARLOS

Distinguished Member
Also do the Diagnostic leds light up and if so which one does it stop on ?

Capture.JPG
 

LoF

Standard Member
The diagnostic LEDs do not light up. The only LED that lights up is this one, it blinks 3 times then stops. I have also tried to boot with gpu and power connectors installed but it still doesn’t work, same result.
image.jpg
 

LoF

Standard Member
image.jpg

I have plugged in the keyboard and mouse and removed the extension white cables to use original, same result I’m afraid.
 

The latest video from AVForums

Podcast: Sony A90J Thoughts, madVR Processor & Sonus faber Lumina II Reviews + Movie & TV roundup
Subscribe to our YouTube channel

Latest News

Harman Luxury Audio Group releases updated MusicLife app
  • By Andy Bassett
  • Published
Q Acoustics announces Q Active app availability
  • By Andy Bassett
  • Published
TCL introduces Roku smart TVs for UK
  • By Andy Bassett
  • Published
Melco Audio introduces new N100-H50 digital music library
  • By Andy Bassett
  • Published
AVForums Podcast: 16th June 2021
  • By Phil Hinton
  • Published

Full fat HDMI teeshirts

Support AVForums with Patreon

Top Bottom