[SOLVED] Cpu LED on no display

[Troy1101]

Had my PC for a few years was running fine until a few days ago. It still turns on just the monitor says no signal and the cpu LED on the mobo is bright red.
I already got a new cmos battery and tried reseating the cpu. I figure the motherboards probably dead but figured I should ask here.

Cpu: i7 4790k
Motherboard: Asus z97-a.
Gpu: Gtx 1080
Psu: evga supernova 750w
Ram: gskill 16gb ddr3 1600

Sorry if it's a bit hard to read had to post from my phone for obvious reasons

 

[Darkbreeze]

Try a hard reset, since you replaced the CMOS battery.

BIOS Hard Reset procedure

Power off the unit, switch the PSU off and unplug the PSU cord from either the wall or the power supply.

Remove the motherboard CMOS battery for about three to five minutes. In some cases it may be necessary to remove the graphics card to access the CMOS battery.

During that five minutes while the CMOS battery is out of the motherboard, press the power button on the case, continuously, for 15-30 seconds, in order to deplete any residual charge that might be present in the CMOS circuit. After the five minutes is up, reinstall the CMOS battery making sure to insert it with the correct side up just as it came out.

If you had to remove the graphics card you can now reinstall it, but remember to reconnect your power cables if there were any attached to it as well as your display cable.

Now, plug the power supply cable back in, switch the PSU back on and power up the system. It should display the POST screen and the options to enter CMOS/BIOS setup. Enter the bios setup program and reconfigure the boot settings for either the Windows boot manager or for legacy systems, the drive your OS is installed on if necessary.

Save settings and exit. If the system will POST and boot then you can move forward from there including going back into the bios and configuring any other custom settings you may need to configure such as Memory XMP, A-XMP or D.O.C.P profile settings, custom fan profile settings or other specific settings you may have previously had configured that were wiped out by resetting the CMOS.

In some cases it may be necessary when you go into the BIOS after a reset, to load the Optimal default or Default values and then save settings, to actually get the hardware tables to reset in the boot manager.

It is probably also worth mentioning that for anything that might require an attempt to DO a hard reset in the first place, IF the problem is related to a lack of video signal, it is a GOOD IDEA to try a different type of display as many systems will not work properly for some reason with displayport configurations. It is worth trying HDMI if you are having no display or lack of visual ability to enter the BIOS, or no signal messages.

Trying a different monitor as well, if possible, is also a good idea if there is a lack of display. It happens.


If that fails to change anything then given the age of the motherboard it's a pretty good probability that you have a dead board. CPUs generally don't just "die" in working systems unless they've been run overclocked with questionable voltage or particularly high clocks for a long period of time and have degraded. It's unlikely to be CPU which means it's likely to be motherboard as that is about six to seven years old now and average age for daily driver motherboard longevity is usually right around five to eight years.

 

[Troy1101]

Thanks for the reply Darkbreeze! I tried hard resetting the bios and plugged in HDMI and got nothing. Seems pretty likely the motherboard is dead. Will try getting a new one and just hope it's not the CPU! Also don't suppose it's possible it could be the PSU?

 

[Darkbreeze]

I mean, it COULD be the power supply, because here's the thing. ALL problems that can happen on a computer CAN happen as a result of any of a number of problems that the power supply might have. ALL problems.

Various failures with a PSU can mimic ANYTHING, because EVERYTHING relies on the power supply. Without it, NOTHING works. So that is always a possibility, however, this particular problem seems unlikely to fit that mold unless there has been a failure on the voltage regulation side of things.

WHICH EVGA Supernova power supply model do you have and how long has that unit been in service?

 

[Troy1101]

I have a EVGA Supernova 220-g2-0750 and it's been used the same amount of time as the motherboard for around 5-6 years. Also not sure if this is changes anything but my bios had been resetting every reset while my PC was still functioning. Figured it was just the cmos battery dying

 

[Darkbreeze]

So, the G2 is a pretty good power supply and technically these came with a 10 year warranty if you registered them within 30 days of purchase. Otherwise they had a 7 year warranty. Either way, you should still be within the warranty period which doesn't mean there can't be a problem with yours but it does make it a bit less probable. If possible, it wouldn't be the worst idea to beg, borrow or steal (No, don't steal. LOL.) another reliable power supply that's at least 550w, and known good, just to test the idea and see if it changes anything.

Otherwise, it sure looks and sounds like a faulty board to me.

 

[Troy1101]

Yeah I went ahead and bought a new motherboard. Gonna be a pain to replace. Honestly if it's the processor that's just unlucky I suppose. Thanks for the help!

 

[Darkbreeze]

Man, ok, my bad, I should have said something earlier but neglected to, but I hope you didn't buy a replacement motherboard for the existing platform. It just, isn't fiscally advisable. Not when those old boards cost so much, and if it isn't old new stock, then it isn't even worth buying at all, and if it is, then it is going to cost too much.

This would be the much, MUCH, better idea, IF you can wait a minute for things to get back in stock which is annoying and painstaking these days.

Honestly, rather than investing in a replacement board for a 7 year old platform, this would be far wiser even if it requires waiting a while to get finances in order. Yes, seems kind of entry level for an i3, but THIS i3 BLOWS DOORS on my 6700k, which still does a decent job for me, so can't be too bad.

PCPartPicker Part List

CPU: Intel Core i3-12100F 3.3 GHz Quad-Core Processor
Motherboard: ASRock Z690 PG Riptide ATX LGA1700 Motherboard ($209.99 @ Newegg)
Memory: G.Skill Trident Z RGB 32 GB (2 x 16 GB) DDR4-3600 CL18 Memory ($129.99 @ Newegg)
Total: $339.98
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2022-02-04 03:34 EST-0500

 

[Troy1101]

You know I forgot processors nowadays are so much more affordable. But if it's any solace I'd like to have the PC up and running decently quickly. It is a bit of a shame when I decide to upgrade I'm gonna need a new motherboard though...Replacing both parts at once would have covered the slim chance my processor is fried... Maybe I should have had a little better foresight but on the bright side the motherboard wasn't too expensive!

 

[Darkbreeze]

I'm going to assume you bought a used one?

What did you get and what did it cost?

 

[Troy1101]

It was Used like new and it was ~170 for a z97-a. Could have gotten one a bit cheaper but the $100 boards were like unlabeled random bored or from sellers with pretty questionable ratings

 

[Darkbreeze]

Ok, but you should be aware that any Z97 or compatible board that you can buy, whether new old stock or used, is likely just as old and just as likely to have similarly degraded caps as your board, so it's really not a very good investment considering it's a 7 year old platform.

I understand the desire to want to quickly get your system back up and running with a minimum of fuss, but paying 170 dollars for a 7 year old motherboard when you could simply invest an additional 170 dollars and get something that outperforms it by almost double, and that will likely last you another 7 years, seems like a less than favorable choice. Hopefully it works out for you AND an additional 170 bucks IS an additional 170 bucks, but I'm really skeptical about investing in these older platforms unless you can get the hardware for REALLY cheap because they simply aren't good investments and are highly likely to have extremely short lived positive results by comparison.

 

[Troy1101]

Yeah a bit of an oversight on my part I should have waited a little while before buying especially with 12th gen processors having just come out recently. Honestly didn't realize the new 12th gen i3 and i5 were as good as they are. Even besides that though it wasn't my greatest idea. Well at the very least I won't make the same mistake twice I suppose!

 

[Darkbreeze]

 

[Troy1101]

It was in fact the motherboard!

 

[Darkbreeze]

👍