The fuse keeps blowing and circuit tripping in the house every time I try to turn on

[Jiminez77]

I recently put a pci card into my Medion desktop to enable it to pick up wireless. It's the first time I've opened it up and the card went in fine.
Everything was working before hand, but now as soon as I plug the computer in and turn the power on, the fuse blows and it trips the circuit in the house.

This is probably unimportant, but to take the cover off, I undid two screws, both with identical heads, but different lengths. I didn't take note of which of the screws went in the top and bottom screws, so now I have the shorter one in the top and the longer one in the bottom.
Could anybody shed any light on what is going on and how I can fix it.

Thanks

[finito]

Hmm, try taking the card out and booting again, is the problem replicated?

Are you sure that the PCI card was Firmly seated in?

[Jiminez77]

Hello, thanks for the reply. I've just checked the PCI card and that is firmly in place. The fuse blew as soon as I connected the power after that.
I thought that it could possibly be a problem with the psu, so I unplugged the 20 pin plug from the motherboard, put a paperclip between the green wire on socket 14 and one of the black earths. Put power through the psu and hey presto, the fuse blew again and tripped the circuit breaker in the house.
I'm really not sure where this leaves me now. I'm thinking, new psu.

[edgaaa]

I think these problems might be caused by your PCI card.. Is any guarantee given to that card? if it is, give it to technical support service and let them check if it is everything ok with that card.. Oooh, firstly I wanted to ask if there was everything ok with your pc before pluging card in? and what about pc when you unplug that card?

[finito]

Yes what Edgaa said,

From what you said the only new edition is the PCI WLAN Card. I would look at that first, try removing it and booting.

[Jiminez77]

I'll explain exactly what I did. Hopefully, I won't sound too foolish as I'm a little bit new to going inside the computer.
I used a video on Youtube to show me how to put the PCI card in. The video suggested loading the driver from the cd first and then opening the computer and fitting the card.
When I received the card, I excitedly unwrapped it and undid the screws for the cover on the computer. I'd taken the two screws out and then though, hold on, the Youtube video said intall the software first. So, I thought I'd do that and turned on the computer, leaving the cover on but not replacing the screws. The power didn't go on from that point and the fuse blew.
I can't see how removing two screws from the casing could have caused this problem.
All that detail is probably completely irrelevant, but that's exactly what happened.
I opened the cover up anyway, to check to see if there were any loose connections, which there weren't and thought that while I had it open, I might as well put the PCI card in. As it stands, the computer has not been turned on once with the PCI card in. The fact that I was putting in the PCI card, might be a complete coincidence.
This could possibly be another irrelevance, but there is a bit of a heated plastic smell inside the computer. I don't know if this is pretty normal as like I say, this is only the third time I've ever opened a computer up.

[Jiminez77]

If this extra detail helps, the computer is a Medion MT175 and the PCI card is an Edimax wireless 802.11b/g Turbo Mode PCI Adapter. It is still guaranteed.

[finito]

Don't worry about the screws. Hmm maybe something is fried.

Please try this remove all Pheriperals, PCI, RAM, VGA, Mouse, Keyboard.

Everything just leave the Processor, Heatsink and the powersupply,

Now Boot

What you want to hear is 4 or 5 Beeps.

If you hear these beeps then you processor, motherboard and Power Supply are ok.

Now add your Ram Back in. Now you want to hear one single beep.

If you get this far then add your VGA and Boot you want to hear a single beep.

Now add your other peripherals one by one you want to hear a single beep.

As soon as you get a short or you don't get the single beep then you have aproblem with that device.

Hope this help, Let me know how it went.

P.S. I can't find anything on google with Medion Mt175 only RAM

[Jiminez77]

The plot thickens a little.
I managed to borrow a psu from a friend. It's 600w and the one in the computer was 400w.
I've put that in and hooked up the motherboard and all the connections to the CD trays and other plugs. I don't know what the other plugs are for, I just matched like for like.
I turned on the computer and the lights went on and fans started spinning. Unfortunately, the monitor simply stated no signal.
What does this mean? That the graphics card is possibly fried?

Incidentally, I opened up the old psu and there was an area of scorching about the size of a 2 pence piece in the middle of the circuit board. I hope that this isn't of relevance as I'm wondering if it's possible the scorching relates to a particular area of the computer that it was supply power to and this is the root of the problem.

[finito]

From the way you talk, I will assume you have some understanding of circuits. As such you know Over or Under volting is not optimal for electrical appliances.

AFAIK There is no revelence to what you are trying to say, The fact that your computer booted without display doesn't say anything concrete.

A Bad processor or Motherboard can also throw the no signal. You must eliminate that by doing what I stated earlier.

When you get the spinning and lights up do you hear any beeps?

[Jiminez77]

Unfortunately, there was no no beeping at all.
I did exactly as Finito said. Oh thank you by the way for detailing what to do.

I removed all the peripherals, RAM, VGA, PCI, mouse and keyboard and booted. The main fan came on and the normal lights on the front, however there was no beeping at all.
From what I've read, this could mean: a short, No power, Bad CPU/MB or Loose Peripherals
I'm assuming that the power supply is OK as that was new in yesterday despite being a second hand psu. I have to rule out loose peripherals as there were none plugged in.

I suppose that this leaves the motherboard and the processor how do I go about assessing the extent of the damage here?

Oh, and it's a Medion PC　MT5

[Jiminez77]

A

[Jiminez77]

B

[finito]

C

[finito]

D

[finito]

Yes you read right, the reason I wanted to eliminate as much as possible is to go bare down to Processor and M/B. Now the only problem you could have is. PSU, MB, Processor, or combination of 1, 2, or all 3 of em.

As for your Machine. Can you please give me the system specs to be able to advise you what your options maybe.

As it stands I believe your machine is a P4 2.8 Ghz. (Correct me if I am wrong)

Hmm in this case I guess you should replace the motherboard first, as I believe it to be the most likely failed component.

You must understand, that even if you change the motherboard, and Processor, you may find other failed components.

You have to weigh your options, New Machines have become extremely cheap, do you want to hassle and fix this one or buy a new one.

Since your machine is dated I would suggest you get a new one, but that is your choice for whatever reason.

It may just be the Motherboard or it maybe the M/B, Processor, RAM, etc. Can't really say. All you can do is test each component in another machine to see if it works nominally.

[Jiminez77]

Thanks, yes it's a Pentium 4, I'm not sure of the Ghz. I realise that it is getting a little old.
I've looked into the cost of a new machine and fixing this one up and I'm just not sure at the moment. I'd be wanting to boost the RAM anyway.
I think that I'm going to go for the repair option. My life isn't terribly interesting at the moment and this'll give me something to fill my spare time up with.

[finito]

My life isn't terribly interesting at the moment and this'll give me something to fill my spare time up with.

Value your time. Time is very precious, I know it's none of my concern, but please value your time. Don't waste it.

I speak from experience. Please PM me if you wish to discuss on this matter. I don't wish to intrude further w/o your permission on the subject.