The impossible problem of no display and no usb power. Try me, I tested everything.... help!!!

[Alex_Labgon]

1. I got a gaming desktop computer here that has no video signal sent to the monitor and no USB power.
   The PC start and light up
2. All the fans (CPU, GPU, case) turn on and the LED (motherboard and fan) too
3. I change the motherboard and PSU to brand new ones and got nothing. They are still in the computer, and the old motherboard is in my second desktop PC, working great
4. I swap the GPU with my other one: no result, but the GPU of the PC having a problem worked great in my second PC.
5. I tried the CMOS technic, no result.
6. Tried changing the ram, reseating it, and starting without it; nothing AND the RAM work great in my second pc
7. I swap the CPU with one I have in my second PC; still nothing
8. Tried starting without SSD and HDD; nothing
9. Tried numbers 5, 6, 8 at the same time; still nothing
10. Tried changing the HDMI cable, no result.
11. DP cable also isn’t working, and changing monitor isn’t working either.
12. Having two monitors at the same time isn’t working either
13. Before all those, I sent the PC to a PC shop and they found nothing. They gave me feedback on what they tried and had said it was either the motherboard or the CPU.
14. When plugging HDMI or DP cable, the monitor get out of sleep but still found no signal
    Guess they were wrong and I lost 126$ with them, kinda sad
    My brother whose pc is to tell me it had started having problems after 3 consecutive power outages and it was the other morning that the no display happen.
    But hey, he like lying so it could also be something else, he also told me windows started having problems first.
    His pc had work for 7 months until he now got a problem.

Do y’all have any other ideas??? ???

Setup
PSU: 750W 80 plus - corsair
Motherboard: ASUS ROG b550-F
SSD: M.2 NVMe 1.4 Samsung 980 250Go
HDD: Seagate 1To
RAM: Corsair Vengeance LPX 16Go DDR4 3600
Case: NZXT H710i White
Thermal paste: Graphite Pad by Innovation Cooling (before you say its the problem, know that my second PC work with this pad and has great temperature with an AMD ryzen 5 )
CPU: AMD Ryzen 7 3800X 8cores
CPU cooler: AMD’s CPU included fan → LED Wraith Prism
GPU: ZOTAC RTX 3060 OC 12Go GDDR6

[Bruce]

is the PC with this issue 7 months old?
if so, it’ll be under warranty still.

that mobo doesn’t have an onbaord speaker, so unless you added one to the SPKR header on the mobo, you would not hear any POST beeps that may indicate an error.
one of these is what you are after;
[ATTACH type=“full” width=“137px”]9185[/ATTACH]

in all that testing, did you reinstall Windows?
have you also tried taking all the components out of the case and reassembling them on a piece of cardboard?
this will eliminate any shorts between the mobo and the case plus allow better swapping in and out of parts until the rig is working.
it also offers a second chance to double check all the connections.

[Alex_Labgon]

good thing is I got a buzzer like this one except it’s doesn’t have the plastic header, but all try making a diy solution.
I don’t know what reinstalling windows could do because it’s installed on the SSD, and even without storage, the computer should still boot on the bios right?
Ima also gonna try building it out of the case to see if the case can be the problem.

Thanks for the tips, all be back to give news

[Alex_Labgon]

Quick Update ---------------

1. I tried the speaker before rebuilding the PC, and I don’t get any sound. I tried connecting it in different ways (5v / gnd, 5v / speaker, speaker as VCC / gnd (tried both))
   I don’t get any sound. Would that mean it doesn’t even boot in bios? (See picture attached to see pin diagram)
2. I found out by reading that one of the Q-LED, the DRAM, is on and stays on.
   It is said it’s due to a problem but I’m not quite sure what it is

Ima start disassembling

EDIT: I got the same motherboard and RAM on my second PC, and the Q-LED form DRAM isn’t on

[Alex_Labgon]

I’m done building it out of the case.
There is now only the power switch of the case that is connected to the motherboard, because of multiple try and fail, I now only have the essential thing connected

1. My second you, so now I know it’s not the problem for sure
2. The mother is new, and I got the old one which the problem had start with in my computer, I know it ain’t the peoblem
   It self but maybe it contain the problem (memory?, dram?? (What is this)?, cmos?)
3. Got the ram etc etc

The problem still persists

[Bruce]

yep, without storage, you’lll still be able to boot into BIOS, and the PC should give off some beeps.

providing you put the + side of the speaker unit to +5v and the - side to the speaker pin on the mobo header unit, you should get sound.
at least one beep to indicate a successful POST and multiple beeps to indicate hardware fault.
for example, 3 short beeps indicates memory or graphics issues.

to force a hardware fault, remove all the memory sticks and boot up - you should get 3 short beeps, that repeat. you could also try that on the other motherboard to confirm a successful test - that is, you do get 3 beeps.

if not beeps on the motherboard with the issue, that would suggest a fault with the board or memory.

this other good PC, can you put its memory into the rig with the issue for further testing?

[PeterOz]

RAM: Corsair Vengeance LPX 16Go DDR4 3600

This from amd
System Memory Specification
Up to 3200MHz

[Alex_Labgon]

After testing, without any memory, the system does send beeps.
But I’m not quite sure if it’s 1long - 2short. Or 3short
I think it’s more of a 1long / 2short but there isn’t a big diff between short and long if it’s the case

I’m also gonna try putting my storage of the my good pc on this bad one and see

Btw Peter, thanks for the answer but 3200Mhz it’s the officials max compatible ram speed for the cpu, but it is possible for it to take more (to a certain point) speed. 3600Mhz work just fine on my pc with a Ryzen 5 3600x, it’s just that over 3200Mhz, if I’m not wrong it will be considered like OC, but yea, my pc is working since January 2020 and still going strong ???

Correct me if I’m wrong, I ain’t no genius and I’m always learning!
Be back with storage test result soon

[Alex_Labgon]

Putting my ssd in his bad pc didnt do anything, but now my pc is slower.. kinda weird

[Alex_Labgon]

a restart make it algood again

[Bruce]

so you have display and USB’s back again, and it’s all working, but slower than before?

[Alex_Labgon]

Ok, seem like i didnt express myself clear ahah

The pc is still not working with display
My SSD in HIS bad PC didn’t work

My PC was slower when I put back My SSD, but it not run normal again after a restart

The problem is still there

[Bruce]

let’s get the PC specs for BOTH PC’s…

download Speccy from here; Speccy - Download Builds
in Speccy, click File > Publish Snapshot > Copy to Clipboard > Close.
paste that link into a post.
One area Speccy doesn’t show is the Power Supply Unit, so also include the make/model of the PSU.

[Alex_Labgon]

Okay but how am i supposed to make it work on the bad PC without display and access to USB?
I can do it on mine tho (the good one)?

[Bruce]

doh!
manually give us the motherboard, CPU, power supply, memory, and graphics details thanks.