Question Seasonic G550 Gold PSU gone(?) but did it damage other components?

eljoantonyn

Reputable
Aug 15, 2019
48
5
4,535
Hi folks !
Here is what happened.

So, I was browsing the internet in the early morning and after some time, I shut the system. It shut down normally, no errors and weird sounds or anything. But, after that, it wouldn't turn on. No lights, no display, no fans. Nothing.
So, I called up my PC troubleshooting friend and he asked me to disconnect everything and short PSU's green and black pins and see if the PSU fan turns on but it doesn't. No response from it.
Then, I borrowed a working PSU from him and connected it to my motherboard and graphics card. All other components which needed power like HDD, etc all had the power cables removed with the data cable still connected ( I was in a hurry). And when I turned it on, it would all blink for a second ie., fans and leds on PSU, graphics card etc would turn on for like one second and then turn off its own. No beeps or anything.
My friend says the PSU might have fried the motherboard!

So, what do you guys think?
Is my mobo gone?


Here's my pc config BTW.
Intel i5 4440 + Gigabyte B85 D3H Motherboard
G.Skill Sniper DDR3 1600 mhz 4GB ram x2 nos
Seasonic G550RM 80 plus Gold PSU
WD 1TB HDD x2 nos
Asus geforce 1060 6GB graphics card (blower type fan originally but I removed it and added a high static pressure axial fan)
20W Delta high CFM, high RPM fan-1 nos +2 "normal" CM Fans and a Chinese Fan Controller.
 
Last edited:

eljoantonyn

Reputable
Aug 15, 2019
48
5
4,535
Both PSUs - your original and replacement were modular PSUs. Right?
Did you use any cables from your old PSU with replacement PSU?

If so, then by doing this you may have damaged your hardware.
Seasonic was modular but the other one, a low end Cooler Master 600W was not.

I haven't used any cables from Seasonic while testing the PC with the Cooler Master.
 

eljoantonyn

Reputable
Aug 15, 2019
48
5
4,535
1. Any suggestions as to how to determine which component(s) got damaged ?

2. What would happen to my Windows 10 installation where I had many games installed (Steam and EA games mainly) if I replace the motherboard and CPU ?
I think I need to re-install Windows, right?
I can't imagine re-installing the games (huge downloads size!).

Any help would be greatly appreciated!
 

eljoantonyn

Reputable
Aug 15, 2019
48
5
4,535
Update:
So, three days ago I tried shorting the green and black wires again and the power supply started working!
Then, I connected the other components (except the graphics card) and my computer ran for two days without any issue. It won't turn on now, like it was before.
I tried the shorting thing again but no change.

So, what would be the component causing this issue?
Any help would be greatly appreciated!
 

eljoantonyn

Reputable
Aug 15, 2019
48
5
4,535
No, only one fan, the case exhaust fan is connected to the motherboard. Rest of the fans are connected to the fan controller which receives power from the PSU directly.
Sorry for being vague!
The 20W Delta was connected to the fan controller along with a CM high CFM fan. Both throw the air directly at the graphics card.
I placed the temperature probe of the fan controller at the exhaust side of the graphics card heat sink so that as the temperature of the graphics card increases, the fan rpm increases.
 
My guess is nothing is wrong with the PSU.

A PSU is supposed to not power on if it detects a dead-shorted condition. It is also supposed to run for a second but then shut down if the voltages cannot stabilize. Jumpering the green wire disables this second protection but not the first.

I would immediately disassemble the system and reassemble it with an eye for anything that may cause a short such as an extra standoff or loose screw. One of these days it is going to be running when it shorts again, and in such a case the PSU will not shut off even when things are on fire.
 
  • Like
Reactions: eljoantonyn

eljoantonyn

Reputable
Aug 15, 2019
48
5
4,535
@BFG-9000
Ok. But, it's not that simple!

When I saw my PC not starting, I disconnected all the connections from the PSU and shorted the green and black cables. It didn't work.
If there was a short circuit, removing the cables would certainly solve it. So, it should work then, right ?
But, it didnt.

It only worked after two days of non use.
 
Not necessarily--it may have required an unplug from the wall long enough to drain the caps to reset, before jumpering would work (there's a drain resistor but it doesn't work very fast because it's small for efficiency). The short isn't in the wires, because they have insulation and it would be obvious. But if you look under the motherboard what do you see? No insulation and 1/4" from metal too--just enough for a fallen screw to bridge. And it could be intermittent from temperature or rolling around.

This is why the proper course of troubleshooting is to remove the motherboard from the case and assemble it on a sheet of cardboard to isolate it from the case, then if it works outside of the case, reinstall one thing at a time. For all you know it may have been the cheap Chinese fan controller shorting to the case all this time, and you aren't going to find a short there while playing with PSUs!

If it doesn't work outside the case though, then it might really be the motherboard or PSU.
 
  • Like
Reactions: eljoantonyn

eljoantonyn

Reputable
Aug 15, 2019
48
5
4,535
Not necessarily--it may have required an unplug from the wall long enough to drain the caps to reset, before jumpering would work (there's a drain resistor but it doesn't work very fast because it's small for efficiency). The short isn't in the wires, because they have insulation and it would be obvious. But if you look under the motherboard what do you see? No insulation and 1/4" from metal too--just enough for a fallen screw to bridge. And it could be intermittent from temperature or rolling around.

This is why the proper course of troubleshooting is to remove the motherboard from the case and assemble it on a sheet of cardboard to isolate it from the case, then if it works outside of the case, reinstall one thing at a time. For all you know it may have been the cheap Chinese fan controller shorting to the case all this time, and you aren't going to find a short there while playing with PSUs!

If it doesn't work outside the case though, then it might really be the motherboard or PSU.
Does it that much time to reset ?

Anyway, what you say is logical even though my PC worked for like 2 days without any issue after the first power supply shutdown.

Right now, I have sent my PC for troubleshooting to a local computer repair shop. I'll check the components to see if there's anything wrong when I get it back.

Thanks for your inputs btw!
 

eljoantonyn

Reputable
Aug 15, 2019
48
5
4,535
@BFG-9000

Seems like you are right. My friend just called me to let me know that they suspect there is a short on the motherboard. They have sent the motherboard for service and they want a week to thoroughly check the board.

Lets see what they find.

BTW, if I have to change the motherboard, I must install Windows again, right ?
 

eljoantonyn

Reputable
Aug 15, 2019
48
5
4,535
UPDATE:
I got the motherboard back and it runs now with only one of my G.Skill 1600mhz RAM. When I plug the other one (I have 2 sticks of the same RAM), the system would not turn on and would stay that way for like one day!
The same thing happen if I change the RAM slot on the motherboard! It only work with that particular RAM stick with that particular RAM slot.

Weird !
May be it was the RAM which was causing this issue (initially) ?