need suggestion to select right wattage psu

get a 750 wat psu its plenty power for ur needs

[QUOTE=TVeblen;774440]

raj1402 said:

If the plastic that is melted is on the male connector from the power supply, and the female socket on the motherboard is un-melted and clean, then replacing the power supply will also replace the connector and if the new connector fits correctly into the socket then it would solve this issue (melted parts).

yeah the connector from PSU is melted clearly indicating problem with PSU

the motherboard preventing it from further damage by switching off the system

i guess.


PSU from cooler-master got 2 rails of +12 volts and psu's from corsair

got single rails +12v both are around 40 amps

so which should i select , single rails(corsair) or dual rail(cooler master)

No. Not exactly.

Your description of the effect of Ohm's law is correct, but you are forgetting something. If you have a resistance in the connector, it impedes the flow of electrons, yes. But the end result is that the connection itself becomes a resistor. Resistors are made in different power ratings for a reason, as current flow across a resistance generates heat.

No! What I said (and you quoted it) was exactly right! Note that I was responding to the comment about "resistance so great that the metal contacts become red hot". Please do NOT take what I say out of context.

And you are making assumptions you can't. You talk about resistance in a connector, then that is a bad connection or connector which would have been a problem from the beginning. Or, if it worked loose due to expansion and contraction (along with vibrations from motors and heavy footfalls) - which again, means the connector was not properly secured in the first place, then the motherboard would be shutting down at the interruptions and instability of the essential 12V power, or the PSU would be shutting down after the first arc or so.

That said, if there was arcing, that is simple to determine. Look at the contacts. In DC arcing, the arc is always in the same direction, so black pit marks would be apparent on the metal.

Don't get me wrong - I hope you are right and it is just a bad connector - perhaps a loose wire inside making contact with an adjacent wire - but I think the odds are against that. I don't see a lose connection arcing so much with only 12V potential to cause the plastics to melt. I think that type heat can only be caused by sustained excessive current - which means a near-short somewhere.

raj1402 said:

yeah the connector from PSU is melted clearly indicating problem with PSU

No it does not. You are assuming both the male and female sides of the connection are made of the exact same materials with the exact same melting point characteristics. That is highly unlikely - especially since the PSU and motherboard are made by different manufacturers. You have to look at the entire circuit, not just the component that fried.

PSU from cooler-master got 2 rails of +12 volts and psu's from corsair

got single rails +12v both are around 40 amps

so which should i select , single rails(corsair) or dual rail(cooler master)

I prefer single rails but both are good makers - and that is key to buying a good PSU. The problem with multiple rails is that some reserve must always be set aside for each rail while a single rail keeps all available power available. This has nothing to do with quality of the PSU, or the quality of the power it delivers. But it does mean you may have to buy a bigger multi-rail to ensure you have enough on each rail. It also means the multi-rail system has more parts - therefore more opportunities for something to fail.

Also, of the Corsairs I have used, and that's been several, compared to the Cooler Masters I've seen, the Corsairs tend to be much quieter.

I did the math, and as long as I did it properly, you are partially correct. Based on a dead short on a PSU rail supplying 12V at 20 Amps, an approximately 24" wire would have it's temperature rise to more than 6500 degrees Celcius in one second, or 6.5 degrees C per millisecond.

Oh? Well, not sure how you determine that without knowing the current capability of the conductor. And without knowing at least the diameter or gauge of the wire, and composition of the conductive materials, I don't see how you can determine that capability. And sadly, the ATX Form Factor Power Supply Design Guide does not require specific wire sizes - it only recommends. So who knows what size wires are used in that supply? But either way, it is not important to this topic.

It would take a tremendously bad power supply design for this to happen in the real world, I would think,

Ummm, you mean like the $10 no-name generic PSUs many users buy to save money, or many case retailers "toss in" to make the case sale? Sadly, catastrophic failures, where the PSU takes out everything plugged into it, is not that rare, and all the more reason to buy from a major maker.

thanks for the suggestion i got cooler master extereme power 600 watts!!!
(yeah i checkd with them and mother board isnt affected so got new psu)

So is it all working now?

Digerati said:

So is it all working now?

its since 24 hr i have changed it

and it works fine ,it 's a continuous run!!!