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PSU, dead due to low voltage?

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February 6, 2003 9:37:33 AM

Hey. I have been experiencing problems with the electrical system where I live. One of the main fuses blows, but there's still power, but it seems to be low-voltage or something. (Normal voltage is 220-230 in Norway). Normal lightbulbs gives just a little light, the plate in the microwave turns around on "half-speed" et cetera. But what this also does, is to kill one of my powersupplies. It has happened 2 times, and both times, it's the psu in the pc with an amd cpu that dies. the other one in a p2-300 works perfectly fine.

i've tried changing fuses inside the powersupplies. the first time, resulted in a loud noise, and both fuses on the circuit where my computeres are connected, blew at the same time.

the psu who survied the first incident was placed into the amd computer. next time, it didn't survive. but the new one that i installed into the old pentium-box did.

i have tried to change circuits inside the psu, with no positive results. the last one that died was a standard aopen atx psu at 360WATTS, plenty of power..but when i plugged into the powercable, i could hear the sound of some sparks.. you know, the sound that sometimes comes from the pins inside the box when they come closer to the cables connectors. so it's just like some parts of the psu is still alive.

and the first one was an expensive noise-control super-silented psu... costed 250-300$... :/ 

anyone know what i can do to fix these psus?

and to prevent this from happening (ofcourse, getting the houseowner to fix the electrical system would be a good start but..) will a ups do the job? i don't think a surge powerprotector will do the job, because it seems like it's insufficient current, not way to much.. but will an ups deal with variations in the voltage perfectly?
February 6, 2003 12:01:13 PM

Power supplies should not normaly die from a lack of voltage. I have tested this theory myself when I was running my computers on generator power in the middle of nowhere for a couple of years. When I loaded down the generator the measured voltage just dropped to around 200 to 220. When this happened all that went on was the computer would just go into an endless reboot cycle because it could not got enough voltage. I would first recommend getting a surge protector because thats the most likely suspect. Because as you said you are getting low voltages it is more likely a surge killing the PSU`s. If you have the money to burn though a UPS would also do.
AREA_51
February 6, 2003 12:12:50 PM

so maybe there can come a surge first, and then one of the main fuses blows, and the voltage drops? but why does this only affects the psu of the amd computer (could be just a coincidence.. but)..

think i'll go and buy a surge protector today :D 
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February 6, 2003 8:54:33 PM

The only reason I can think of for it affecting just the AMD computer is because it draws more power so the PSU is already stressed from the start. Thats all I can think of.
AREA_51

'It's only when you look at an ant through a magnifying glass on a sunny day that you realise how often they burst into flames'
February 7, 2003 5:26:56 AM

A UPS would certainly help, and might just cure the problem

<font color=blue>There are no stupid questions, only stupid people doling out faulty information based upon rumors, myths, and poor logic!</font color=blue>
February 8, 2003 9:57:27 PM

I think your 2 AC lines are unbalanced, with one having much more voltage to ground than the other. So an UPS would suffer just as badly.
February 8, 2003 10:40:44 PM

You clearly dont understand electricity. (No offence meant) If I understand what you are inplying is that you think that one line is overvolted in relation to ground. Well that is not relivent. You have 3 lines here in Australia and though there may be slight diferences around the world that is pretty much standard. You have the Active Neutral and Earth. There is no current flow from earth to active or neutral. It NEVER carries current. All the current flows between the Active and Neutral creatung a circuit. So it is not possible to get more voltage on 1 line killing his computer. It would be aross both if it was and would be readable with a multimeter. Just thought I would point that out.
AREA_51

'It's only when you look at an ant through a magnifying glass on a sunny day that you realise how often they burst into flames'
February 9, 2003 9:39:54 AM

This is the Europian system: 2 lines (third optional):
Line one (blue): this one carries the load (active)
Line two (brown): this one goes back to the ground in the transformator house in your neighborhoud. (neutral)
Line three (green/yellow): earth ground for safety... directly connected with the ground(water) under your house.

I never heard that one of the 2 lines can have an overload (unless lightning strikes) so I think you're right.

My dual-PSU PC is so powerfull that the neighbourhood dimms when I turn it on :eek: 
February 9, 2003 10:44:37 AM

Thats basicaly the setup that we have here in Australia. Except it is brown for active and blue for neutral. And the earth line is mandatory here.
AREA_51

'It's only when you look at an ant through a magnifying glass on a sunny day that you realise how often they burst into flames'
February 9, 2003 11:19:08 AM

Well it could be that I mixed the wires and that brown is active and blue is neutral.

My dual-PSU PC is so powerfull that the neighbourhood dimms when I turn it on :eek: 
!