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[Solved] Bang and spark at the end of the kettle plug type lead

mij

Valued Donating Member
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Aug 6, 2009
Location
East Sussex
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Some Experience
5 minutes ago
#41



Thanksfor that KenB, I have had a look at the mobo but nothing is obvious from this side. I will look again tomorrow morning with daylight as my eyes are not what they used to be.

I took a look at the old PSU that went out with a bang and a big spark. A capaciter seems to have blown its glass end off and at the end of a white lead there is a large blob of something. Peering through the mesh of one of the good PSUs the white lead should have a white plug at the end. Perhaps this has melted during the bang/spark! It seems it may have taken out other electronics that it was connected to. Oh dear, I feel a rebuild coming on :censored:. I have attached a photo of the old PSU, the white blob (melted white plug) is at the end of the white lead and just up from the green rectangular board. The flash has made the photo difficult to see and if that is so I can do another tomorrow in daylight.
Jim.
1746-e58edd55440dbb80a2b67891a858ad09.jpg
 
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mij

Valued Donating Member
Joined
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Location
East Sussex
PC Experience
Some Experience
I have just tried that thumbnail and it didn't enlarge on this loopy laptop. It works one day then nothing the next. I'll try again tomorrow.
Oh for my W7 machine.....
Jim.
 

mij

Valued Donating Member
Joined
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Location
East Sussex
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My 2nd photo of the burnt out PSU is attached hopefully. Without the flash it is a little more obvious of the damage to the PSU. It shows the melted white plug but the blown 'glass' capaciter is end on and not so visible. It is next to the melted white plug and just above it.
Jim.
PS It wasn't until I magnified the image that I saw the largish capaciter had melted black something (used to be pitch) and closer inspection showed what I thought was a glass capacitor was looking more like a fuse that had blown apart. I think you may have known that.


2nd photo of the burnt out PSU.jpg
 
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mij

Valued Donating Member
Joined
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Location
East Sussex
PC Experience
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I have done the next check and with the 1st new PSU connected to the mother board, there is no turning of the fans in the PSU or the fan on the mobo itself :(.

I assume this means the mobo and/or the chip is defunct :( ?
Jim
 
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KenB

Administrator
Joined
Oct 19, 2008
Location
Wirral UK
Hi Jim,
Can you post some close-up pics of your motherboard please ?

Before I suggest that it is dead there is something I would like to check.
 
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mij

Valued Donating Member
Joined
Aug 6, 2009
Location
East Sussex
PC Experience
Some Experience
I have tried to get close but the photo goes out of focus. I can always try again if these are unsatisfactory.
Jim.mobo1.jpg

mobo2.jpg

mobo3.jpg

mobo4.jpg
 

KenB

Administrator
Joined
Oct 19, 2008
Location
Wirral UK
Hi
Thanks for the photos - they are a bit blurred - but I did manage to locate the Model Number.
Gigabyte GA-78LMT-USB3

The manual can be found here - http://download.gigabyte.asia/FileList/Manual/mb_manual_ga-78lmt-usb3_v.5.0_e.pdf

There is an ATX 12v connection on this board. [ see image ]
1537285711880.png

Try the following: Assuming that you left the M-Board in the case ?
1. Unplug from the wall.
2. Connect the 24 way connection.
3. Connect the ATX 12v connection.
4. Put in 1 RAM module

Now be VERY careful again ....
5. Plug in the PSU to the wall socket and switch on
6. Press the On / Off button on the case. [ Keep your eyes away from the PSU / M-Board ....just in case ]

Is there any life showing now ?
 
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mij

Valued Donating Member
Joined
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Location
East Sussex
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Some Experience
Before I carry out this move one of the leads left over was the ATX lead which should have 12V on each yellow lead. But there is only four connecters on it. I have leads here which adapt 4 connecter plugs to the 8 connecter plug on the mobo. They simply take two yellow and make them four yellow which are connected to all one side of the ATX connecter. Similarly with the two black leads from the other side of the PSU plug. Two black leads into the four connecters on the motherboard. That might sound like gobbdy gook, perhaps a photo will help. Maybe I should use these as it will supply life to the whole plug.
Jim.

4 to 8 adapter leads.jpg
 
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KenB

Administrator
Joined
Oct 19, 2008
Location
Wirral UK
Hi Jim,

Maybe I should use these as it will supply life to the whole plug.
???
They simply take two yellow and make them four yellow ....
If your PSU doesn't have an 8 pin ATX 12v connector you will need to use one of the 4 pin to 8 pin leads as you suggest.
[ unless the PSU has 2x 4 pin connectors that would do the job ? ]
 
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mij

Valued Donating Member
Joined
Aug 6, 2009
Location
East Sussex
PC Experience
Some Experience
Thanks KenB for staying with this. Your help is much appreciated here.

KenB said
unless the PSU has 2x 4 pin connectors that would do the job ?

It has just the one. Ok I have tried it and nothing turned or lit up. It looks as if that mobo is dead. Unless you think different?
Jim.
PS Reading back over your instructions I did not put the RAM back in, how important was it to this test?
 
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mij

Valued Donating Member
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Location
East Sussex
PC Experience
Some Experience
I've just put the ram in and it made no difference at all. Dead as dodo.
Jim.
 

KenB

Administrator
Joined
Oct 19, 2008
Location
Wirral UK
I did not put the RAM back in, how important was it to this test?
Not that important - you would have seen some evidence of life.

It does look like the M-Board was taken out when the PSU died.

Where do you want to go from here ?
 

mij

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Location
East Sussex
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Thanks KenB for continuimg with this, it's one of those jobs isn't it.

I would like to get another mother board if it's possible. I assume these might still be on the market? I cannot stand this horrible W10 thing :(.
Jim.
.
 

KenB

Administrator
Joined
Oct 19, 2008
Location
Wirral UK
I did see a new board here - click here

The PSU could have taken out RAM / CPU and any other hardware that was attached to the board.
 

mij

Valued Donating Member
Joined
Aug 6, 2009
Location
East Sussex
PC Experience
Some Experience
Thanks for looking that up for me KenB. That seems reasonable at £51.88. Although I may need more than a mobo as it was all connected when it went bang. The chip and fan I'd get as a matter of course and I'd expect them to be costly as well. Are they as easy to get? Is there any more vunerable bits left? The RAM perhaps?

I could get ordering today if you can stick with this :). I am motivated by this loopy laptop.
Jim
 

KenB

Administrator
Joined
Oct 19, 2008
Location
Wirral UK
Hi Jim,

Just because the RAM etc were connected to the M-Board doesn't mean that they WILL have been taken out.

The chip and fan I'd get as a matter of course
Do you mean the Central Processor Unit [ CPU ] and attached fan?

It could be that the original is OK.

If it were me - I would get the M-Board first and see what happens from there.

If the CPU has gone west too then a basic replacement could be about £50 - £60

4GB RAM would cost about £25

Do you have the original Win7 disk ?
 

mij

Valued Donating Member
Joined
Aug 6, 2009
Location
East Sussex
PC Experience
Some Experience
Thanks for that information KenB, as you can tell I am lost with this stuff.

You said-
"Do you have the original Win7 disk ?"

I have a couple of W7 disks some where here, I'll have to look up the one that came with the machine.

There looks to be a lot of dust in the fins of the heat sink underneath the cooling fan. Is it ok to remove the fan and use the vacuum cleaner to make it more efficient as a cooler? I'd have to take the CPU off the mobo to achieve that.
Jim,
 

Rustys

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Aug 28, 2017
Location
Here since I am not there
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Very Experienced
Is it ok to remove the fan and use the vacuum cleaner to make it more efficient as a cooler? I'd have to take the CPU off the mobo to achieve that.
I will have to state NO refer to the second NOTE and leave the heat sink on the CPU.

Get some cans of compressed air and blow the system clean. Make sure the system is powered off and unplugged. Remove the battery if a laptop if the battery can be removed.

Read the instruction on the can. Spray in short burst and when the can start to feel cool to the touch switch to a different can. After they warm up to room temp they work fine.

Do this in a well ventilated room or outside this way the dust does not settle all over the inside furniture or worse you or someone inhaling it.

Do NOT turn the cans upside down turn the system. Remove the battery and blow that our as well.

NOTE: You take the chance of wrecking the bearings with the compressed air. Compressed air can actually accelerate the fans beyond their rated speeds and damage them, if you are cleaning them out with air, it is often recommended to hold the blades in place with a toothpick or other non-conducive material.

NOTE: Do not use a vacuum to clear the dust they can cause a static discharge and end up toasting the system or a components. There are also jumper on the boards that could be sucked off and then the system would be bricked.
 

mij

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Joined
Aug 6, 2009
Location
East Sussex
PC Experience
Some Experience
Thanks Rustys, all noted and will folllow those guide lines :).
I tried ordering the mobo this evening and I am unsure if it went through or not. I will ring them tomorrow morning and check. Each site is not always like the usual.
Jim.
 
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