ISO 400PP PSU Fuse

  snowy30 00:26 21 Apr 2008
Locked

I expect the PSU needs changing, but before I do is it possible to change a fuse in a ISO 400PP 4 PSU?

My bro brought his son's computer down for me to look at, there is no power - it's completely dead. I checked the plug, changed a fuse in that, used a wire connection from one of me comps and still there is no life. I also checked the connections inside too. I found one on Ebay for £9.99 + p+p of £6.95.

Are the fuses in the PSUs interchangable?

  DieSse 12:57 21 Apr 2008

Well they are - but

It may not be the fuse that's made the PSU "dead"

Even if the fuse has blown - that is normally because something is seriously wrong. Replacing it can do substantial damage to the PC if you're unlucky.

  DieSse 12:59 21 Apr 2008

And BTW they're not easy to replace as they're normally soldered in.

I guess the real message is - don't try.

  snowy30 18:06 22 Apr 2008

Well, changed the PSU and still no power

  wiz-king 18:14 22 Apr 2008

Do you mean no power ie no fan running or lights anywhere or do you mean it is not working?

  Fruit Bat /\0/\ 18:15 22 Apr 2008

Oh dear sounds as if the old PSU took the motherboard and maybe the CPU with it.

  Diemmess 18:22 22 Apr 2008

It may be that the motherboard is kaput. If you are unlucky there can be a domino effect, one component overloading another.

I assume the monitor shows at best - "no signal" and there is a total absence of lights on the PC.

One thing you could try is to find the leads from the Power-On switch and briefly short the leads at the point where they reach the motherboard.

This is a low voltage circuit and provided you only short the two pins where the lead plugs on to the mobo there will be no fireworks or detrimental activity, you are only proving that it isn't the switch itself.

  snowy30 18:31 22 Apr 2008

It's completely dead - no life whatsoever.

And Diemness.
You assumed correctly. No lights, no signal. How will I go about shorting the two pins?

  snowy30 18:32 22 Apr 2008

It's completely dead - no life whatsoever.

And Diemness.
You assumed correctly. No lights, no signal. How will I go about shorting the two pins?

  Diemmess 18:49 22 Apr 2008

You have to trace the thin cable from the switch on the case, to a collection of such leads on the mobo.
There will probably be leads to LEDs maybe the case speaker, reboot switch and so on.

If you follow it through you will finish at a small black plug Pull this off (gently) and then anything, a suitable screw driver which can touch both bare gold plated pins at once. You are doing what you would normally do when you switch on with a push switch like a doorbell.

Don't hold your breath!
It is unlikely to be a switch fault but they do go wrong very occasionally, and it costs nothing to try this.

  snowy30 19:01 22 Apr 2008

Still no life. Completely dead.

I placed a screwdriver across the plates of the small black plugs as suggested but still no life.

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