No POST in just assembled computer that got on fire

[Federick]

Hi there,
I'm italian and this is my first time writing here in Ltt. I read the thread "README: How to respond to a no POST or no power up situation"  and used the search function but I didn't find anyone with my exact problem. 
 I have assembled my pc with these specs:

Asrock AB350M Pro4
Amd Ryzen 3 1200
Zotac GTX 1060 AMP!
Crucial 2x4gb (DDR4)
 Corsair CX450M
 Western Digital Blue 1tb
Case: Corsair Spec-Alpha Carbide Series

This case has two front fans and a rear fan. The rear fan has been connected directly to the mobo using the apposite pins. The front fans are connected to the front panel of the case (where there is a switch to regulate the fans' speed) and finally a SATA cable connects the front panel to the PSU. 

This was important because this is the part that went on fire. 
After everything was assembled, i turned the computer on and the risult was:
- Every fan moving (comprehensive of CPU and PSU)
- ‎the fans' switch was working properly
- but ‎no signal to the monitor (not even the BIOS)
After forcing the shut down and restarting, the computer started rebooting every 30 sec. Still no signal to the monitor.
After forcing the shut down and restarting again, the computer was always turned on without giving any signal to the monitor (but without rebooting). 
Every forced shut down could alternately switch the computer's behaviour. 

After some minutes while the computer was shut down but the PSU was powered on, I felt like something was wrong because i was sniffing that something was burning. 
Thinking that it was just my imagination,  I switched on the computer. At that point the cables of the front fans started melting, and the SATA cable alimenting the front panel got on fire. 
Immediately I plugged off the PSU and 
detached any front panel cable from the fans. 
At this point I switched on again the computer and... Magic! The BIOS appeared on screen and everything worked. I rebooted with the USB pen drive inserted in for installing windows, and also in this case everything went well. I kept the computer on for several minutes to understand if there was something melting again and tried also to reboot it a couple of times and still everything worked. 
So I was sure that the problem was this connection between the front fans and the front panel of the case. I switched off the PSU to move the computer from where I assembled it to where I would place it everyday. 
But again, when i've plugged in and switched on the pc, no signal has arrived to the monitor. Again if i force to shut down it begins looping. 
The same as before but the fact that nothing seems to be melting. 

I followed some guides in the internet and tried these:
- changing the monitor (seems stupid, but evrntually i tried)
- ‎restarting the CMOS
- ‎reseating everything
- ‎tried to power up eliminating one component at the time, till switching on with only CPU and mobo. Still no signal on screen. 
- ‎cut off the melted cables in order to avoid further short circuits. 

What do you suggest?
Grateful for your cooperation, 
Greetings
Federico

[Ashleyyyy]

wait a minute, you are troubleshooting a machine that got on fire? 

 

unplug it, and keep it off. 

 

electrical fire is something you don't want to mess with... 

[aisle9]

Return the mobo, PSU and case. You likely have a massive short somewhere, and those are the three components that appear to be affected or potentially causing it. Do not troubleshoot an electrical fire. Return it and make it the OEM's problem.

[justinas2003]

2 minutes ago, aisle9 said:

Return the mobo, PSU and case. You likely have a massive short somewhere, and those are the three components that appear to be affected or potentially causing it. Do not troubleshoot an electrical fire. Return it and make it the OEM's problem.

Some wires were shorting. 

[Guest]

Erhm @firelighter487... With a username like yours, I would expect a different attitude.

 

TS: I can't seem to notice any burn damage on your cables. But you do seem to have some stuff connected, which is optional/towards the case. Maybe try and disconnect that and try again? Maybe remove it entirely from the case, and put it on a cardboard (mobo)box, and see if it will post then?

 

If it doesn't work, just RMA it.

 

PS: had some "minor" electrical damage on my preveous mobo. Onboard audio got actually fried/clear damage to the PCB. After taping off the wrinkled PCB wires, it worked for another 10 years. (and still going strong)

 

 

[Ashleyyyy]

1 minute ago, Dutch-stoner said:

Erhm @firelighter487... With a username like yours, I would expect a different attitude.

haha i didn't even realize..

[justinas2003]

1 minute ago, Dutch-stoner said:

Erhm @firelighter487

PS: had some "minor" electrical damage on my preveous mobo. Onboard audio got actually fried/clear damage to the PCB. After taping off the wrinkled PCB wires, it worked for another 10 years. (and still going strong)

 

 

How the hell your pc worked for 10 years? 

[Guest]

Keeping it on 24/7 usually helps. Good maintainance. Swap out the ocasional burned up low-range GPU, adding ram, adding moar storage... Keeping expectations realistic. (it sits currently at my GF's house as a YT/series/movies pc, which she ocasionally uses for lightweight indi games) @justinas2003.

 

Oh, it also helps that it's an AMD pc.

[Federick]

Spoiler

 

Thanks everyone for the answer. I didn't attach the photo of the burnt cables because i cut them off somewhere before point where the plastic melted. In this way i hoped to solve the problem because maybe the problem was a second shortcircuit in these cables. I want to underline that the "only" burnt cables where those coming from the case, namely the SATA connector for the PSU, and the fans' cables. All these cables come from the front panel of the case (that i inspected without finding any macroscopic damage). 

 

I Also tried to boot the mobo on its box, but I didn't manage to power it up with a screwdriver as seen in some Yt video. Maybe it was mobo's fault, or more probably it was mine. In any case, the only thing i connected from the mobo to the case was the power on button. Also running the mobo on its box (with only CPU, PSU and 1 RAM) there was no

POST. i don't know if the experiment can be considered valid since that I connected the power on button of the case as said. 

 

In the meanwhile, thinking the PSU was the guilty guy, I returned the cx450m to have a new one back. But also in this case, with a New PSU still no post. 

 

 

Quote

Return the mobo, PSU and case. You likely have a massive short somewhere, and those are the three components that appear to be affected or potentially causing it. Do not troubleshoot an electrical fire. Return it and make it the OEM's problem.

 

Can i do that? Couldn't the OEM say that i assembled badly the computer and so that it was my fault?

 

I excluded as a cause of the problem:

- the PSU

- the case (Q: can we consider the test negative even if the power on buttonnwas still connected to the mobo?)

 

So remains the mobo.. Do you agree?

[SupaKomputa]

burnt cables usually from over current, that should be the psu fault not mobo.

so i would assume the original psu got screwed, this can be from the bad front panel or fans connections.

then the bad psu screwed the mobo.

you changed the psu with the new one, but the mobo already fried.

 

so now i think, since its a new motherboard, just RMA it.

as long as there's no physical damage / burnt stuff, they cannot blame you for the damage.

 

replace the troubled fans or the case which maybe the culprit in the first place.

 

Quote

i don't know if the experiment can be considered valid since that I connected the power on button of the case as said. 

disconnect all pins to the front panel.

to power up you simply short (touch 2 pins) with a screwdriver or metal object.

this does the samething as a power button.

 

Quote

Also running the mobo on its box (with only CPU, PSU and 1 RAM) there was no POST.

aha... this is a classic Ryzen mistake. where did you connect the monitor if no gpu plugged? how do you asses if the mobo not post? do you have a speaker plugged in?

[Federick]

20 hours ago, SupaKomputa said:

burnt cables usually from over current, that should be the psu fault not mobo.

so i would assume the original psu got screwed, this can be from the bad front panel or fans connections.

then the bad psu screwed the mobo.

you changed the psu with the new one, but the mobo already fried.

This is what I was Thinking too!

Quote

 

so now i think, since its a new motherboard, just RMA it.

as long as there's no physical damage / burnt stuff, they cannot blame you for the damage.

 

replace the troubled fans or the case which maybe the culprit in the first place.

 

I agree for the mobo. Of course I cannot RMA the case since there are burnt or cut cables, can I?

 

Quote

aha... this is a classic Ryzen mistake. where did you connect the monitor if no gpu plugged? how do you asses if the mobo not post? do you have a speaker plugged in?

Directly to the mobo through VGA. Indeed i also tried to connect the GPU and connect the monitor via HDMI, but also in this case no signal arrived qto the monitor. 

[SupaKomputa]

Quote

I agree for the mobo. Of course I cannot RMA the case since there are burnt or cut cables, can I?

why don't you try it. explain what happened. maybe they will replace it.

Quote

Directly to the mobo through VGA.

Yes, this is the classic Ryzen troubleshooting mistake. The mobo doesn't have build in vga, neither the cpu, so you won't see anything.

 

Go get one of this thing :

 

place it in your motherboard (see manual) and see if its beeping.

 

Have you tried to reset the bios to default, find a jumper pin on the side of the board that said "CLRCMOS1".

there are 3 pin in that socket, 2 of those connected by a jumper, pull the jumper and place it in the opposite pin (1-2 to 2-3).

unplug power cable, and wait 30 seconds and then place back power cable and the jumper to pin 1-2. then boot.

 

 

[Federick]

Quote

Yes, this is the classic Ryzen troubleshooting mistake. The mobo doesn't have build in vga, neither the cpu, so you won't see anything.

Oh gosh! So maybe also the GTX got fried?!?

20 hours ago, SupaKomputa said:

Have you tried to reset the bios to default, find a jumper pin on the side of the board that said "CLRCMOS1".

there are 3 pin in that socket, 2 of those connected by a jumper, pull the jumper and place it in the opposite pin (1-2 to 2-3).

unplug power cable, and wait 30 seconds and then place back power cable and the jumper to pin 1-2. then boot. 

yes I tried. Still no POST. 

 

20 hours ago, SupaKomputa said:

place it in your motherboard (see manual) and see if its beeping.

Thanks for the advise. I will keep you uptaded

[Federick]

To answer those who asked and for readers' sake, The problem was the very first thing we excluded because so unprobable: the second PSU was broken too! Of course the first one had fried the mobo and the VGA. Good luck if you are stuck in my same problem.

Thanks to all who helped!