A shorted USB input can cause more problem ...

 

Image Source: PCmag

I had a bad scare just a few days ago!

I was installing my unsuccessfully returned Transcend SSD into my PC when something horrifying happened! 

My PC went dead! It won't turn on at all!

And worst, it was leaking electricity! I just kept getting small jolts of shocks when I touched any USB ports, any exposed metal or even the screws on my casing!

I thought it must be the problem with my power supply unit (PSU)! So I removed it and did a paperclip test by inserting the 2 ends of a paperclip into 2 different pins to try and short it. (You can see the tutorial here) And somehow, it still didn't run! So the PSU is probably dead. 

I asked a friend of mine and he said that I probably fried my motherboard! Which made my heart sink! If a motherboard is fried, it could also affected everything else that is connected to it - like the GPU, ram and even the SSD/HDD! I was pretty devastated, I just spent more than a thousand on my PC and it's dead now!!!

However, my friend told me not to despair yet and do further testing first. So I removed my current PSU and then run an old PSU on it (but it's missing the GPU PCIe cable connector and it has only a 4 pin connector instead of 2x4 pin which my motherboard needs) so I couldn't test the GPU and not sure if enough power is supply to my CPU.

Turned out that my motherboard could turn on but not so sure about my CPU since my PC could only output video through the GPU.

Well, at least my motherboard is pretty safe... I contacted Cooler Master (since my PSU is still under warranty) and they asked me to run through a few test ... 

I was pretty reluctant to try but I still decided to follow their instructions to clear the CMOS - removing the battery and wait for 1-5 minutes.

Somehow, when I was opening the case again, I realised that there is one USB connection that I didn't remove. Probably missed it since it wasn't in the way; it was long enough for me to open the case easily and do all the testing.

So I removed it... and then did the CMOS clearing... I connected everything back and... surprisingly, everything started to work! 

Erm... so what is exactly the problem? 

To be honest, I don't know the whole theory behind it. I just know that the particular USB port that I didn't plug out is having power issue - when I tried to plug it in, there is a small spark!

So it was the one who is causing the electricity leak! Well, it's powered by an external power source via a MicroUSB cable, and that cable happened to be faulty! So it was causing the "short".

I'm not sure how a small "faulty" USB connection could actually affect the WHOLE computer, preventing it from even powering up! But at the same time, I'm pretty glad that the protection on my PC is good enough to prevent further damage!

Replacing a MicroUSB cable is definitely cheaper than having to replace any of the PC parts!!

Phew, what a relief!!