[SOLVED] CMOS reset killed new MOBO?

[colra901]

Background: upgrading an old PC tonight with new MOBO, RAM, CPU.

Was able to get lights on fans etc upon first build but no POST. To try and get the system to POST I hit to "reset CMOS" button on my board, as indicated in the MOBO manual. Since then, we can't even get the fans to turn on. When we plug in the GPU, it's power socket has a tiny light, so PSU seems to be working.

Troubleshooting:

• checked CPU, RAM were compatible on vendor site
• completely removed all pieces from case, cleaned it out, and reset them after the initial POST failure, no changes
• connected only CPU, RAM (1 stick), MOBO and tried to boot
• left PC unconnected for 15min, tried to boot
• used another PSU, same issue
• swapped out RAM
• ensure RAM was in the correct slot as indicated by the manual (DIM2)

Can anyone clue me in as to what to try next? I'm pulling out my hair here, nothing I understand about CMOS should be working like this?

Build details
New components:
MOBO: MSI Performance Gaming X470 Gaming Plus AM4 AMD X470 SATA 6Gb/s USB 3.1 HDMI ATX AMD Motherboard
CPU: AMD RYZEN 7 3700X 8-Core 3.6 GHz (4.4 GHz Max Boost) Socket AM4 65W 100-10000007
RAM: G.SKILL Ripjaws V Series (2 x 8GB) 288-Pin DDR4 SDRAM DDR4 3200 (PC4 25600)

Re-used components (working fine before):
PSU: Corsair 750TX
GPU: MSI GeForce GTX 1070
HDD: Seagate STBD3000100 3TB 7200 RPM 64MB Cache SATA 6.0Gb/s
OS: window 10 Pro
Case: Corsair 400C White Steel ATX Mid Tower

 

[Darkbreeze]

How old is that TX unit?

What is the exact model of the "other" PSU you tried, and how old is THAT one?

Memory should be installed in the second and fourth DIMM slots, which are generally A2 and B2. That is for ALL dual channel motherboards. Often misinterpreted by confusing language in the user manuals, but ALWAYS correctly interpreted when you look at the graphical population rule images. If you do not have them in the A2 and B2 slots, as seen below, even if that is not the problem, you should STILL move them to those slots, and then do a hard reset INCLUDING switching off the power switch on the power supply and then switching it back on after the procedure has been completed.

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 five minutes. In some cases it may be necessary to remove the graphics card to access the CMOS battery.

During that five minutes, press the power button on the case for 30 seconds. 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 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, 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.

 

[colra901]

initial PSU age - when I checked, over 5 years old yikes! I will look into a replacement in the AM

the second PSU I tried was actually a lot newer, in the last 2 years or so from a newer PC build

What might the older PSU have impacted, just curious?

 

[Darkbreeze]

I'm not too worried about it having "impacted" anything, just not being up to snuff anymore due to age, degraded, etc. These units generally lose some amount of capability each, for lack of a better measuring stick, year. Capacitors degrade. Things break down. And when a PSU is not working right, nothing is working right.

What is the EXACT model of the 2 year old power supply?