No POST Solid Blue LED

[Jayley]

Hello all, need some help here

My 5 years old PC is having a no Post issue. Open up the chassis and saw a solid blue LED light (DIAG_CPU LED).

It happened after coming back from 1 week vacation. Previously my PC has this issue as well, it has this no post issue but I just left it alone and a few days later it works. This only happen when I don't touch my PC for a long time (like 1 week). The first time it happen was when I went oversea again for 1 week. But this time, it didn't come back.

I tried the rubbing contact point of my rams and graphic card. Tried power drain. Nothing works.

Specs below:
Asus z97 WS MB with i7 - 4790k
AS Strix GTX980 4gds
Vengeance LPX 16gb ddr4 DRAM 2400MHz
Cooler Master 850 (PSU)
Nepton 280L Liquid Cooling Kit

I pray its my PSU but I would like some professional insight on this, thanks

 

[singupingu]

There's an indicator on the motherboard regarding the blue led light that lit up. What is the indicator says on the motherboard? Your motherboard have multiple indicator LED so we won't know which light is it that lit up and what does that light indicate.

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[abcdefgh123]

u got q-code leds. there is a 2 error code you can what it means. https://dlsvr04.asus.com/pub/ASUS/mb/socket1150/Z97-WS/Manual&QVL/E12543_Z97-WS_UM_V2_WEB.pdf

 

[Jayley]

Thanks for the reply! I tried zooming in, it says "DIAG CPU".

There's an indicator on the motherboard regarding the blue led light that lit up. What is the indicator says on the motherboard? Your motherboard have multiple indicator LED so we won't know which light is it that lit up and what does that light indicate.

Sent from OnePlus ONEPLUS A3003 using GAGT

 

[shadow84]

Thanks for the reply! I tried zooming in, it says "DIAG CPU".

Means there is an issue with cpu. Either mismount or cpu is dead. If u can get another 4th gen haswell cpu to test, it would help determine a more concrete result. I doubt its mounting issue since u have been using for a long time.

 

[Jayley]

You found the manual! I tried finding the eBook but couldn't find it online. There were only 2 codes shown throughout the entire boot up phase.

0C 14 - Reserved for future AMI SEC error codes, Pre-memory CPU initialization is started

00 76 - Not used, PCH DXE Initialization (PCH module specific)
I look them up in the manual but can't really figure out the meaning.

u got q-code leds. there is a 2 error code you can what it means. https://dlsvr04.asus.com/pub/ASUS/mb/socket1150/Z97-WS/Manual&QVL/E12543_Z97-WS_UM_V2_WEB.pdf

 

[Jayley]

Dead CPU? It's a first for me to encounter such situation ._.

Means there is an issue with cpu. Either mismount or cpu is dead. If u can get another 4th gen haswell cpu to test, it would help determine a more concrete result. I doubt its mounting issue since u have been using for a long time.

 

[singupingu]

CPU hardly fail, though not impossible.

Possibly part of the mobo died too. Try boot with barebone? Single ram, no gpu, only boot ssd and remove all other drives. Remount cpu and reapply thermal paste at the meantime. See if you can borrow a confirmed working psu from a friend? If your psu half dead (not supplying the correct or sufficient voltage), your pc won't boot too.

If it boots slowly add back one thing at a time and see which is giving issue.

After everything and still won't boot, like it's CPU or mobo died.

Not hard to hunt for another Z97, but it's better to build a new one. 3rd Gen AMD Ryzen on the horizon. Be launching next month if you're not in a hurry?

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[Phen8210]

try reset bios also