[JADJr]

I just built a new desktop computer, and it did not power on. No fans or lights, except for one instance when the light on the power button came on. Since operator error on my part is very possible, I wanted to check the power supply. I used a Kingwin tester, and attached is an image of the results. The tester beeped continuously, and the number 120 under "PG" blinks.

Can anyone interpret these readings for me?

Thanks.

 

[Bill_Bright]

I have the same tester. It beeps because the -12VDC is missing or wrong. But that's not a problem. -12VDC is no longer a requirement. As long as the +12VDC, +5VDC and +3.3VDC are present, and within the allowed ±5% tolerance (and they are in your case). Then your power supply is fine.

So something else is wrong. Make sure all your power connections are tight and secure. Check your motherboard and graphics card (if using one) manuals to ensure all power connectors are used.

Note that cases are designed to support 1000s of different motherboards. So, it is common for cases to have more motherboard mounting points than boards have mounting holes. And while the ATX Form Factor standard dictates where motherboard mounting holes “can” be on motherboards, it does not dictate where they “will” be. So, one board may have a mounting hole in a specific place while another may not.

A common mistake by the less experienced and distracted pros alike is to insert one or more extra standoff in the case under the motherboard. Any extra standoff creates the potential for an electrical “short” in one or more circuits. The results range from "nothing" (everything works perfectly) to odd "intermittent” problems, to "nothing" (as in nothing works at all ). So, you might want to verify you only inserted a standoff where there is a corresponding motherboard mounting hole.

So, if you are sure you made all the proper connections, I recommend taking everything out of the case and assembling the computer on a large, unfinished bread/cutting board to see if it boots there. Then inspect the case and verify again, only the necessary standoffs have been installed in the correct places before reassembling back inside the case.

 

[JADJr]

Thanks for that reply. I wanted to check the PSU before I started over again or RMA'ed the case. Operator error is certainly possible here.

 

[Bill_Bright]

or RMA'ed the case.

The case? It is highly unlikely the case if at fault - unless the box it came in looks like it fell off the delivery truck a couple times.

 

[JADJr]

The case came with PSU and AIO pre-installed, so if the PSU were bad, I would RMA the case.

The AIO makes it difficult to build outside of the case, now that fan is attached to the CPU, but I will see what I can do.

 

[MPR]

Your motherboard, if it is a standard ATX, will require nine standoffs. Your case will be set up to be able to install several other sizes of motherboards though and will have additional standoff positions. You need to look to see which standoff positions align with the holes in you motherboard and place the standoffs accordingly. It's not that hard, if you count out nine standoffs and the proper nine mounting holes in your motherboard are filled then you have things correct.

You will need standoffs of the proper height. If they are too low then the solder tails of your motherboard will short out against the case. It's pretty easy to determine this too. Just install enough standoffs onto your motherboard to make it a "table" and then set it on a table and look under it to see if everything is clearing. If something from the motherboard is touching the table then you need higher standoffs.

Also, follow your motherboard's manual when building a system. There's a reason why commercial pilots with thousands of hours of flight time still read from a checklist on each and every flight. If you don't follow a checklist, it's easy to forget a necessary connection. And speaking of connections, if you don't hear a "click" then they probably aren't seated properly.

 

[Bill_Bright]

Your motherboard, if it is a standard ATX, will require nine standoffs.

Sorry, but that is not true. Please read my post #2 above.

As noted above, ATX Form Factor standard does not dictate how many standoffs are used. It only dictate where they will be located - "IF" used. This means an ATX motherboard might only have 7 or 8 mounting holes and not 9 and still be consider a standard size ATX board - as opposed to a microATX or extendedATX board.

For this reason, users must verify standoffs are inserted in the case are only located where there is a corresponding motherboard mounting hole, and ensure there are no extra standoffs under the board.

 

[MPR]

Sorry, but that is not true.

Nine mounting holes are standard since ATX 2.01 and all of the current ATX motherboards I looked at on Newegg had nine mounting holes. However, you are probably the person to find that rare white raven. I believe that there are four known to exist in the world.

Must be used

All ATX board mounting locations shown in Figure 2 should be implemented for chassis assemblies to achieve full ATX 2.01 compliance and to provide proper support for the board in these areas. Mounting hole locations ATX A, C, F, G, H, J, K, L, M. Hole at F must be implemented in all ATX 2.01-compliant chassis assemblies. It was optional in the ATX 1.1 specification.

https://web.aub.edu.lb/pub/docs/atx_201.pdf

 

[Bill_Bright]

I hear you, and you are right about the boards - at least for new boards designed since that ATX version came out. Thanks for that - I should have done my homework better.

HOWEVER in reading it carefully, "should" is used in there a lot instead of "will".

Plus, users cannot be sure when a motherboard or a case was designed. So, IMO, my advice stands and we must ensure motherboard mounting holes and standoff mounting locations match to ensure no extra standoff is under the board.

 

[SoCalBryan]

So, a few questions;

What is the motherboard brand and model?

I see empty memory slots in the posted pic. Do you have memory installed?

If I remove my memory chips and then put them back, I have to wipe the CMOS (short the CMOS jumper pins) and then it will boot.

The other way is to pull the CMOS battery, wait 15 seconds, put it back in, then try to boot it.

 

[JADJr]

Hello, all, and thanks for weighing in. Additional details on my build: I am using the CoolerMaster NR200P Masterbox case. It is SFF and comes with PSU and AIO cooler installed. I am using the Asus ROG STRIX B660-I board. It has just 4 screws to attach it to the case. I did install everything, including the RAM, but when I could not power up, I started disassembling the system in order to check all my connections. I also decided to test the PSU before I tried reassembling, just to see if that might be the issue.

At one point, I did see the light at the power switch on the case top go on briefly and then not again.

I am trying to see if I need to RMA the PSU, that is why I did the testing. I am just not sure if what I see indicates a problem.