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Tellarix
Journeyman III

PC Turns on but no display or peripherals (CPU LED light on)

Hello

I have an issue, when I turn on the pc it powers up (fan spinning, rams shinning) but there is no display or my mouse doesn’t work, however, my keyboards keys light is on

 

I updated my old pc all component except GPU -thanks market – and hdd and ssd

 

At first it worked fine, I then increased the rams speed to its advertised speed (3200), it worked fine after a while my pc was restarting randomly, I decreased the ram speed to 3032, it restarted and worked fine after a while it shut down and now when I turn on the pc it powers up (fan spinning, rams shinning) but there is no display or my mouse doesn’t work, however, my keyboards keys light is on.

 

my motherboard has in Ez debug LED it was shining on Dram then after updating my bios to latest version only CPU LED was on

 

Specs:

Motherboard MSI B550 A pro
CPU ryzen 5800x

CPU Cooler: Lian Li Galahad 240

Rams CORSAIR Vengeance RGB Pro 32GB (2 x 16GB) 288-Pin DDR4 SDRAM DDR4 3200

GPU MSI 980ti

HDD: Seagate 3TB

SSD Samsung evo 860 250g

M.2 NVMe Samsung 970 EVO SSD 500G

PSU: Seasonic FOCUS Plus 750 Gold

Case: Lian Li Lancool II mesh

 

Things I tried

-put rams in different slots, use single or double rams

-use different rams ( my old ones HyperX Kingston  Fury 2666MHz DDR4)

-try different bios update by flashing my motherboard

-reset cmos (by removing the battery and waiting few hours, )

- changes cmos battery

-reseat my GPU

-Reseat CPU and reapply the cooler and paste

-Tried different power supply

-removed everything on the motherboard except CPU

 

 

so I think what is left is only trying another motherboard or CPU

Sadly I don’t have any spare atm and I cant go to a shop

 

Is there anything that I can try to fix this ?

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11 Replies
Robinhood
Adept I

When you say you increased the RAM to its advertised speed, then decreased it to 3032, how did you do this exactly? Did you turn on XMP? Or did you manually set the RAM to that frequency? 

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i manually set it to that frequency by choosing  it from a drag list in the bios 

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Can you try resetting the BIOS to default and only turning on XMP?

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how can i do that without any display ? 

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Good point. When you flashed the BIOS, are you positive that you took it from your specific motherboard's website, and the correct revision of the motherboard? 

Also, you're using an AIO liquid cooler. Do you have anything plugged into your motherboard's CPU 4-pin fan header? 

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i made sure its to correct motherboard and tried different bios versions, 

the i have the aio fans connected to the cpu fans on the motherboard ( and it spins when i turn on the PC)

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Remove all the RAM sticks except one and see if you get Video output when you power up.

If  doesn't and you still get the CPU Trouble LED light on your motherboard, remove all the connected hardware to the motherboard including GPU and Keyboard and mice. Just leave the CPU installed and no other hardware.

Power up and see if the CPU Trouble LED  light goes off and the DRAM Trouble LED light goes on. If it does, at least that indicates your CPU is good and passed the BIOS test and found no RAM installed so it lit up the DRAM Trouble LED light.

If it still stops on the CPU Trouble LED Light with just the CPU installed then you either have a defective CPU or Motherboard.

Now install one RAM Stick and see if the DRAM Trouble LED light goes off and the GPU light goes on. If it does then install the GPU and monitor and keyboard and mouse and see if you get Video Output.

This is to try and see which hardware doesn't pass the BIOS test. No need to remove the motherboard. Just disconnect all hardware to the motherboard.

 

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i removed all motherboard components , just kept the cpu, the DRAM led was on instead of CPU. But when i added ram it went back to cpu led, no matter the slot, single or double

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The CPU passed the BIOS test when you powered up when the CPU LED light went off and then the DRAM LED Light going on.

Did you add both RAM sticks or just one?

If installed both just install one RAM stick and see if it goes past the CPU Trouble LED.

At least the problem is between the CPU, RAM or motherboard.

can you post the exact RAM part number you have installed (Make & Model)?

EDIT: Found this old thread concerning a MSI B450m Gaming motherboard and CPU Trouble LED light being on: https://linustechtips.com/topic/1111486-cpu-led/

Some MSI motherboards have a bad habit of letting up the CPU LED error light when actually the ram is at fault. What happens when you run with XMP off for a while?

Also try connecting a PC Speaker to see what Beeps you hear when you boot up?  Just using the CPU and RAM installed first.

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You mentioned you had a different set of RAM, Hyper X 2666 DDR4. Are you saying you tried running one stick of this different RAM and it still gave you a CPU LED error? 

rawintellect
Miniboss

Have you tried pulling out the BIOS battery while the unit is unplugged? This will set the BIOS back to defaults.

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