Is "blowing a motherboard" actually possible?

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grimstoner

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I have an external hdd, with it's own (missing) power supply.

Taking the first spare power supply I have lying around that fits (a 19.5V one), proceeded to plug it in. The moment the USB cable touched, I heard a (incredibly loud) pop, and the power (of the house) went down.

Hoping, I tested the computer's PSU, which unfortunately, is fine.

I have a DP45SG mobo, with a little power LED on the mobo itself. When I connect the PSU, this LED lights, but if I press the power button, nothing happens. I've also tried bridging the switch pins, nada. I've removed all the addon cards, nothing (hopefully, this means my graphics card is fine).

So, what's more likely to go? The motherboard or the CPU?
 
Mobo, easy.

How do you know the PSU is fine? Remember there are 3 main segments: power to your mobo, power to your drives and a loop back power to your monitors.
 
I would test another psu first. You could easily have popped the mobo circuit in the PSU. It's far more likely that a PSU will pop rather than a mobo, although a mobo can pop.
 
grimstoner said:
I have an external hdd, with it's own (missing) power supply.

Taking the first spare power supply I have lying around that fits (a 19.5V one), proceeded to plug it in. The moment the USB cable touched, I heard a (incredibly loud) pop, and the power (of the house) went down.

Hoping, I tested the computer's PSU, which unfortunately, is fine.

I have a DP45SG mobo, with a little power LED on the mobo itself. When I connect the PSU, this LED lights, but if I press the power button, nothing happens. I've also tried bridging the switch pins, nada. I've removed all the addon cards, nothing (hopefully, this means my graphics card is fine).

So, what's more likely to go? The motherboard or the CPU?
Click to expand...

There lies the problem. What is the correct voltage and/or polarity required for the ex-hdrive ? Seems like you fed a 19.5V signal directly into the usb port (5V), that would be damaging to the mobo. If you heard a pop you should see and smell the damage somewhere on the mobo. I am sure the ext drive will also be a goner.
 
wily me said:
There lies the problem. What is the correct voltage and/or polarity required for the ex-hdrive ? Seems like you fed a 19.5V signal directly into the usb port (5V), that would be damaging to the mobo. If you heard a pop you should see and smell the damage somewhere on the mobo. I am sure the ext drive will also be a goner.
Click to expand...

It's a Seagate GoFlex Desktop 3Tb. It's got a little desktop mount, which is where you plug in the power supply. Doesn't the hdd motor require 12V? I thought if it requires 12V, it should have some over-voltage protection and the 19.5V would be fine.
 
grimstoner said:
It's a Seagate GoFlex Desktop 3Tb. It's got a little desktop mount, which is where you plug in the power supply. Doesn't the hdd motor require 12V? I thought if it requires 12V, it should have some over-voltage protection and the 19.5V would be fine.
Click to expand...

Lol dude. Hahahaha. You know what thought did?
 
An external harddrive requires 12V. The 2.5" drives require 5V, hence they can be powered by USB.
 
What most likely happened is a USB short (or something similar, like current coming up from the USB enclosure) hit the mobo (at least) and the PSU's overload protection (if it had any) failed to trigger (maybe all the current was coming from the external side) and so enough amps were pulled to trip the mains board. In order of what I would guess is most likey damaged: motherboard -> PSU -> add-in cards -> CPU.

Do you know where the pop came from, the PC or the external power supply?

Did you check the polarity of the 19.5v power supply?
 
I popped my mobo by just plugging my CPU fan on the wrong 3 pins of the 4 it had on the mobo .... burnt track and everything... 1 X 2.5k Asus P8P67 pro dead! (everything else was fine .. only mobo died)
 
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grimstoner said:
It's a Seagate GoFlex Desktop 3Tb. It's got a little desktop mount, which is where you plug in the power supply. Doesn't the hdd motor require 12V? I thought if it requires 12V, it should have some over-voltage protection and the 19.5V would be fine.
Click to expand...
What i can gather from the net is that the goflex need a 12V DC source with the polarity 0V (-) on the outer contact and 12 (+) on the inner pin. I doubt if there was a regulator internally to reduce the 19.5V down to 12V as these units are designed to work with their own power supplies, they are not manufactured to be universal. Any 12V source of the correct polarity and pin size would work. On the drive there will possibly be protection in the form of a resistor that blows. I repaired one recently where exactly the same incident happened where a friends 19.5V laptop supply was used on a external HD adapter instead of a 12V. In this case only the Hdrive failed, no mobo damage, and I replaced one resistor on the drive to make it work again. (I do electronic repairs, my own and friends.)

http://support.moonpoint.com/hardware/power/adapters/

(search for goflex on the web page)
 
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Kosmik said:
I would test another psu first. You could easily have popped the mobo circuit in the PSU. It's far more likely that a PSU will pop rather than a mobo, although a mobo can pop.
Click to expand...

Just did. No go... so, fairly certain it's the mobo.
 
Sounds like the mobo took the punch unfortunately :( Can you see any damaged IC's or parts on the board?
 
wabbit16 said:
Sounds like the mobo took the punch unfortunately :( Can you see any damaged IC's or parts on the board?
Click to expand...

Had a good look, can't see anything. Dunno if maybe the north bridge has gone, and because it's covered by a cooler, can't see it? Is the USB hardware integrated on the north bridge?
 
Is there a smell coming from the board? If so, it could be a circuit or a part that has been damaged and as you say, it could be covered by a heatsink
 
grimstoner said:
Had a good look, can't see anything. Dunno if maybe the north bridge has gone, and because it's covered by a cooler, can't see it? Is the USB hardware integrated on the north bridge?
Click to expand...

USB isn't on the north bridge, it's usually on an io chip.
Your motherboard and hdd are most likely toast though but the rest will most likely be OK.
 
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Phoned the reseller... mobo warranty expired 2 weeks ago.

Sad face.
 
Is "blowing a motherboard" actually possible?

Hate it when these things happen. Sometimes I fake for granted how fragile pc tech equipment is and do stuff like using any power supply with any piece of equipment. Your lesson learnt is our lesson learnt.
 
grimstoner said:
It's a Seagate GoFlex Desktop 3Tb. It's got a little desktop mount, which is where you plug in the power supply. Doesn't the hdd motor require 12V? I thought if it requires 12V, it should have some over-voltage protection and the 19.5V would be fine.
Click to expand...

:wtf:. One should always keep true to the voltage ratings unless you the engineer who designed it :whistle:
 
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