Bought a new PSU, connected everything, PC only boots for a fraction of a second

[Frantisek_1]

Hello, I need your help. Recently I've been considering buying a new GPU (especially since the old one gone bust), XFX RX480 GTR, but I figured I should buy a new PSU for it first. My system specifications:

Asrock H87M mobo
i5-4590 (with aftermarket cooler)
No GPU atm, only integrated
Win 8.1
2x8 GB RAM
1 SSD and 2 HDD (+DVD drive)

The old PSU was Corsair CX430M, now I bought EVGA 550 G2.
I installed the new PSU, but when I pressed the power button, the system only powered up for a split second before turning off, and it did the same thing again only when I flicked the IO switch on beside power cable on and off, otherwise it didn't bother to try again.

I checked if all the cables are inserted well in correct places, and it seems that they are. I googled but haven't really done anything more (firstly disassembling and assembling everything again is a pain, and secondly I am afraid that I break something if I am going to do that often, I don't really have the money to buy new components often).

Any suggestions on how to proceed?

Thank you for all help.

 

[Vithu Sel]

Hi, Can we have a bit more info on what happened to the old PSU?
Did it just stop working or was there a bang?
There is a possibility of a power surge before the psu died therefore damaging internal components.

 

[InvalidError]

If the PSU refuses to turn on until you cycle its power switch, it means that the PSU encountered a fault condition while trying to power up and went into lockout mode to force manual intervention before another power-up can be attempted.

Usually, that happens because something is shorted out and trips the PSU's over-current/over-power protection.

 

[Frantisek_1]

Vithu Sel:

Nothing happened to the old PSU, it was working just dandy, it's just it probably wouldn't be enough for the new GPU, so I wanted to upgrade it as well. I have a surge protector too.

And if you mean the old GPU, it broke one day when I had to do a sudden reset (holding the power button for a few seconds) when a game froze, then until I disconnected it there were graphical glitches everywhere (like green strips on the screen) and my system was having all kinds of errors because it wanted to use the card even though I switched to onboard graphics (I even reinstalled the system in hopes of fixing it), but the problems have disappeared once I took the bad card out.


InvalidError:

That's what I thought too after googling, so I checked and it doesn't seem like the mobo is touching the case and the cables are oriented the correct way. Can that be caused by sweat? My fingers were sweating a little, especially when I was manipulating the CPU cable which is hard because there is little room because of the heatsink (and I didn't feel like disassembling it).

 

[InvalidError]

Sweat on the cables shouldn't matter but if a drop of sweat landed on the motherboard, GPU or other high power component, anything could have happened depending on where that landed in the circuitry. Bad luck with ESD at some point during the swap-out process is also a possibility.

Double-check everything that you moved/removed and that you have no surplus connectors touching things they shouldn't be. Check for pinched or damage wires too.

 

[Frantisek_1]

It's not like my fingers were dripping sweat, lol.

What do you mean exactly by everything I moved/removed?

My cable management is abysmal, but I tried to take care that nothing is pinched or touching anything conductive.

I'll do that tomorrow after work, probably, thanks for helping me.

 

[InvalidError]

What do you mean exactly by everything I moved/removed?

Anything you may have touched, nudged, removed and re-installed, etc. while removing your old PSU and putting the new one in is a potential suspect. For example, if you pulled on the GPU while unplugging the PCIe power cable, the GPU may have partially come out of the PCIe slot and shorted something there. If you nudged a DIMM, it may have partially come out and shorted something there. Everything that may have moved or been touched is a potential suspect.

Another way to proceed would be to remove all unessential components and see if that helps. If it does, put the rest of the stuff back in one by one, checking if the PC still boots between each component addition.

 

[Frantisek_1]

Some progress in my situation:
I have about two hours before I go to work, so I just thought I would look over if the cables are connected well and disentangle them a bit. I did and everything checked out, so I tried disconnecting my two HDDs from power. You see, the two drives are powered from one Molex cable (through splitting expansion cable) which also powers the front and back case fans. I run the machine without the two drives connected and the fans spun up and it seemed to run normally. Mind you, this setup was working just fine with the old PSU.
So I think I have these possible culprits:
- the splitting cable is not connected to the drives properly (nudged out)
- the splitting cable is bad
- the connection between the splitting cable and Molex is messed up
- the Molex is bad

 

[Frantisek_1]

Update:
I just tried the cables connection into drives, they felt solid. But then I tried looking at the connection between the splitting cable and Molex and the Molex has one hole a little bent. I will try replacing it.

 

[Frantisek_1]

I have some Molex cables which came with the PSU, but none of them exactly matches the configuration of the pins on the PSU end of the cable I want to replace. Does it matter a lot?

 

[Frantisek_1]

I have replaced the cable, but another thing came up, which might have been the real cause of my issues - the split cable powering the HDDs had a weak pin, and now it was pushed out of the connector entirely. I'll have to buy a new one. Hopefully it will work.

 

[Vithu Sel]

If that does not work. I would suggest unplugging all the power connections and try running the psu on its own. you can connect the green wire and any black with (motherboard connector plug 20 or 24pin) to trick the psu to boot. I would suggest having a hard drive plugged in to produce a load. Do be careful when shorting these two cables i havent heard of anyone hurting themselves before. You can do it with a paperclip and then hit the power button on the back of the psu to turn it on.