Question I'm building a PC but having problems getting it to POST ?

[D Pete]

I have built a computer before but it has been several years. A lot has changed since then. I couldn't find a prebuilt computer with the specs I wanted. So I got the components from Newegg. Assembled everything in the case, turned on the power supply. Nothing happened. Reseated the memory, CPU, video card, all the cables in the motherboard and PSU. Still no power. Ended up taking the motherboard out of the case and tried with the minimum amount of memory, etc. plugged in. The CPU fan LEDs, four LEDs on the front and three LEDs on the back of the motherboard lit up for maybe 1 – 2 seconds. That is all. Nothing more happened.

I thought it might be the power supply. Purchased a PSU tester. The following is the results of those tests with two different PSU since I thought I was getting bad readings from the first PSU. I purchased another one thinking that the first was bad. The second PSU had somewhat similar readings. So I tested an old one I already had. Far different readings than the two new ones.

1st PSU: MSI - MPG A850G
-12V 12.1
+12V2 12.7
5VSB L.L
PG 0ms
+5V 5.0
+12V1 12.3
+3.3V 3.3

2nd PSU: CORSAIR RMx Series RM850x
-12V 13.5
+12V2 12.5
5VSB L.L
PG 0ms
+5V 5.0
+12V1 12.0
+3.3V 3.3

3rd PSU: an old one
-12V 12.4
+12V2 L.L
5VSB 5.2
PG 260ms
+5V 5.2
+12V1 12.4
+3.3V 3.4

The remaining components:

CORSAIR 7000D AIRFLOW Full-Tower ATX PC Case​

ASRock B650M Pro RS WiFi AM5 AMD B650 SATA 6Gb/s Micro ATX Motherboard
CORSAIR Vengeance RGB 192GB (4 x 48GB) 288-Pin PC RAM DDR5 5200
MSI Ventus GeForce RTX 3060
AMD Ryzen 9 7900X - Zen 4 12-Core 4.7 GHz - Socket AM5
Cooler Master Hyper 212 Halo Black CPU Air Cooler
SAMSUNG 990 PRO 2TB SSD, PCIe Gen4 M.2 2280
The free gift from Newegg: Patriot P400 Lite M.2 PCIe Gen 4 x4 1TB SSD, Solid State Drive

Is there something here that I am missing? Is the motherboard bad or is it the power supply or both? I am in a sort of time crunch because Newegg's return policy. I didn't think that this would still be a problem nearly 3 weeks after getting everything together.

I appreciate any and all help.

 

[DaleH]

I have built a computer before but it has been several years. A lot has changed since then. I couldn't find a prebuilt computer with the specs I wanted. So I got the components from Newegg. Assembled everything in the case, turned on the power supply. Nothing happened. Reseated the memory, CPU, video card, all the cables in the motherboard and PSU. Still no power. Ended up taking the motherboard out of the case and tried with the minimum amount of memory, etc. plugged in. The CPU fan LEDs, four LEDs on the front and three LEDs on the back of the motherboard lit up for maybe 1 – 2 seconds. That is all. Nothing more happened.

I thought it might be the power supply. Purchased a PSU tester. The following is the results of those tests with two different PSU since I thought I was getting bad readings from the first PSU. I purchased another one thinking that the first was bad. The second PSU had somewhat similar readings. So I tested an old one I already had. Far different readings than the two new ones.

1st PSU: MSI - MPG A850G
-12V 12.1
+12V2 12.7
5VSB L.L
PG 0ms
+5V 5.0
+12V1 12.3
+3.3V 3.3

2nd PSU: CORSAIR RMx Series RM850x
-12V 13.5
+12V2 12.5
5VSB L.L
PG 0ms
+5V 5.0
+12V1 12.0
+3.3V 3.3

3rd PSU: an old one
-12V 12.4
+12V2 L.L
5VSB 5.2
PG 260ms
+5V 5.2
+12V1 12.4
+3.3V 3.4

The remaining components:

CORSAIR 7000D AIRFLOW Full-Tower ATX PC Case​

ASRock B650M Pro RS WiFi AM5 AMD B650 SATA 6Gb/s Micro ATX Motherboard
CORSAIR Vengeance RGB 192GB (4 x 48GB) 288-Pin PC RAM DDR5 5200
MSI Ventus GeForce RTX 3060
AMD Ryzen 9 7900X - Zen 4 12-Core 4.7 GHz - Socket AM5
Cooler Master Hyper 212 Halo Black CPU Air Cooler
SAMSUNG 990 PRO 2TB SSD, PCIe Gen4 M.2 2280
The free gift from Newegg: Patriot P400 Lite M.2 PCIe Gen 4 x4 1TB SSD, Solid State Drive

Is there something here that I am missing? Is the motherboard bad or is it the power supply or both? I am in a sort of time crunch because Newegg's return policy. I didn't think that this would still be a problem nearly 3 weeks after getting everything together.

I appreciate any and all help.

I haven't use a PS tester. Does the tester measure the voltage with everything connected? If so, then voltages are ok. If not, then one needs to measure them with a voltmeter and everything connected, as the problem may only appear with the load connected to the power supply..

 

[punkncat]

Do you have spare components you can test some items with?

I do find something odd about the mobo support page. The CPU you have is supported by BIOS 1.18 which appears to be the base BIOS. All of the memory on the QVL is showing BIOS 1.28 (or higher) for almost everything.

I would expect that if this was a RAM issue that you would have a debug light or speaker code. The quick power up and power down may be hard to diagnose on your own.
Do you have a good mom and pop store around?

 

[D Pete]

When using the PS tester, its the only thing attached to the cables. I'm not sure how much load it provides.

I don't have any other spares other than the old power supply, unless I pull apart an old computer that I stole the hard drives from. I attempted to update the latest BIOS version but I don't think it worked. The lights don't tell me much of anything and if there is a speaker on the board, never heard a thing. I contacted Asrock and all I got was a message that their voice mailbox was full and never heard back at all when I submitted a support ticket. There is a computer repair store here. I'll have to call them.