The motherboard CPU LED is illuminated following the PC cleaning process?
The motherboard CPU LED is illuminated following the PC cleaning process?
I just cleaned up my old PC and now it isn't booting correctly, the CPU LED is lit.
I've already done these steps:
- Reseat CPU, GPU, RAM, PSU cables
- Tried a different CPU on the same board
- Removed CMOS battery for 10 minutes
Any further actions needed before giving up?
System details:
MBD: ASUS Z97-A
CPU: i7-4790K
GPU: EVGA GTX 1070
RAM: HyperX Fury 16GB
SSD: Crucial MX500 1TB
PSU: Corsair RM650x
Case: Fractal Design Define R4
How intense was your cleaning process? Did you possibly dislodge a tiny surface mount part from the motherboard or GPU card? Were any electrolytic capacitors (if present) around the CPU VRM stages? Did you follow correct ESD (Electro Static Discharge) precautions during cleaning to prevent static-sensitive parts from suffering a dangerous electric shock? Even a low voltage of 100V and static voltages above 1000V are common in practice.
https://automotivetechinfo.com/2016/12/p...ge-damage/
Did you disconnect any PSU leads without properly reconnecting them?
Have you inspected the CPU socket with a magnifying glass to check for bent or missing metal contacts?
I don’t mind a thin layer of dust in older computers, but I’d take action if it became severe.
https://terablitz.com/hardware/how-to-cl...ty-pc-diy/
I didn't see anything coming loose or any ESD effects since this isn't my first cleaning session. I only clean it when the buildup becomes substantial enough to force out dust each time I begin using the computer.
99 times out of 100, you're blissfully unaware of potentially causing ESD damage. The only time I've felt a static shock is when walking across a carpet in a large hotel and reaching out for a metal door knob.
At work, it was mandatory to observe full ESD handling precautions, including ESD work benches, ESD lab coats, ESD foot wear, ESD wrist straps, etc. This was for completed units as well as bare prinnted circuit boards.
You don't want airplane navigation and control systems or satellite electronics to fail, just because some technician zapped a module with static (and yes I know there is usually redundancy in aerospace equipment).
However, I think it unlikely your problem is due to ESD.
Have you tried a different PSU?
Have you tried the iGPU built into the i7-4790K instead of the PCIe GPU? Sometimes a blank screen is because the BIOS has reset back to providing output on the iGPU instead of the main graphics card.
There have been times when I've plugged my monitor cable into the motherboard iGPU output by mistake and been greeted with a blank screen.
I also recommend removing all system RAM apart from one stick and see if the system POSTs. If it does boot up, power off and fit the remaining DIMMs. Sometimes removing RAM "jump starts" awkward systems when clearing the BIOS fails.
What does the motherboard manual say about the CPU_LED? Does it provide any clues, apart from a CPU detection fault?
In these circumstances, I'd eventually swap all components over to one of my other LGA1150 boards, to see if the motherboard has failed, then search eBay for a similar second-hand board if necessary. Of course, there's no guarantee the replacement won't also have problems.
Okay I just just fixed it by removing the CPU and lightly blowing out any unseen debris. Now I have another problem, after I shutdown the computer, the next boot up has intermittent self shutdown before I get to the post screen, then it tries to boot up again and and shuts down again then it repeats.
I need to understand why you suspect dust or other foreign particles might be present in the socket. It appears the repair hasn't fully resolved the issue, but at least the system is partially functioning as it should. Did you try using a magnifying glass and spend five minutes inspecting each tiny spring contact inside the socket? If any of these are slightly misaligned, it could cause inconsistent contact with the CPU, which might explain your ongoing difficulties.
As the image demonstrates, the spring contacts are extremely small, making it difficult to detect misalignment easily. You might need to take the motherboard out of its case for a closer inspection. Make sure to use bright light from various angles when examining.
Please refer to this guide: https://www.youtube.com/watch?v=dd_vhLd8ykc
CAUTION: It's quite simple to break bent contacts while trying to fix them, which could damage the motherboard. While repairing a broken contact is possible, you'll need a replacement board, a hot air rewelding tool, and precise tweezers.
Some contacts are less critical, such as power/0V connections since multiple contacts can perform the same role; losing one isn't usually a big problem. Others are essential, like memory bus connections, because they have no backup options.