New psu - no power to system.

[tom]

Hi there.

My power supply on my PC is overheating, so I decided to buy a new one.

I made sure that the one that I bought was ATX with 20pins and had the 4 pin
connector for P4. It does. The only difference between the old one and the
new one is that the new one is 450W and the old one was 300W. All of the
cables and connectors are the same.

I disconnected the old PSU and installed the new one, everything is plugged
in exactly as it was previously. I push the button on the front of the
machine and nothing happens - no lights, no fans, no beeps, nada. I
reconnect the old PSU, and it works (although it still overheats after an
hour or so)

Have I been unlucky and been sold a faulty PSU, or is there something else I
should try before I take it back?

Thanks.
Tom

 

[Ken]

Hi there.

My power supply on my PC is overheating, so I decided to buy a new one.

I made sure that the one that I bought was ATX with 20pins and had the 4 pin
connector for P4. It does. The only difference between the old one and the
new one is that the new one is 450W and the old one was 300W. All of the
cables and connectors are the same.

I disconnected the old PSU and installed the new one, everything is plugged
in exactly as it was previously. I push the button on the front of the
machine and nothing happens - no lights, no fans, no beeps, nada. I
reconnect the old PSU, and it works (although it still overheats after an
hour or so)

Have I been unlucky and been sold a faulty PSU, or is there something else I
should try before I take it back?

Thanks.
Tom

Is there an on/off switch on the rear of the PS????

 

[hdrdtd]

also, look on the back of the PS. is there perhaps a little slide switch
used to set the AC voltage?

If so, they are ususally shipped with it in the 115vac position, but I have
heard of the switch being set to 220 or whatever rather than the needed
115vac setting.

 

[tom]

Thanks to both of you for getting back to me.

The voltage is set to 230V (I live in the UK, so this is correct)
There is a power switch on the back, it is set to the on position. I tried
in both the on and off positions in case the switch was labelled
incorrectly.

Is there a maximum wattage that can be connected to a motherboard? The
reason I ask is because both PSUs are the same brand, but the new one is a
more powerful model and output is the only obvious difference between the
two PSUs.

Thanks
Tom

 

[Michael Hawes]

Thanks to both of you for getting back to me.

The voltage is set to 230V (I live in the UK, so this is correct)
There is a power switch on the back, it is set to the on position. I tried
in both the on and off positions in case the switch was labelled
incorrectly.

Is there a maximum wattage that can be connected to a motherboard? The
reason I ask is because both PSUs are the same brand, but the new one is a
more powerful model and output is the only obvious difference between the
two PSUs.

Thanks
Tom

Send it back, it is faulty!
Mike.

 

[Ken]

Thanks to both of you for getting back to me.

The voltage is set to 230V (I live in the UK, so this is correct)
There is a power switch on the back, it is set to the on position. I tried
in both the on and off positions in case the switch was labelled
incorrectly.

Is there a maximum wattage that can be connected to a motherboard? The
reason I ask is because both PSUs are the same brand, but the new one is a
more powerful model and output is the only obvious difference between the
two PSUs.

Thanks
Tom

The wattage rating is the maximum that it can put out. Your computer
and its components will draw what they need, and as long as it does not
exceed the maximum, you will be OK. I would make sure your connections
from the PS are secure and not reversed anywhere. If one were to
somehow be reversed the PS would go into an over current condition and
shut down immediately. Start with all accessories (HDs, CD drives,
floppies, and anything else) NOT powered or attached to the MB. You are
just interested in seeing some life on the monitor. Once it starts, add
one component at a time.

 

[tom]

Took your advice and tried it without any component cards, usb, etc
connected. Just the graphics card, memory and CPU. I got nothing. I added
the components one at a time to see if that made any difference, testing
each time and getting nothing (I also tested the old PSU which worked every
time.) Thanks for replying, but it looks like the new PSU might just be
DOA. I'll take it back to the place I bought it and ask them to replace it.

Tom

 

[tom]

I am pretty sure you are right. I was just unlucky I guess.

I shall take it back and ask for a replacement. Thanks for your advice.

Tom

 

[larry moe 'n curly]

My power supply on my PC is overheating, so I decided to buy a new one.

How do you know it's overheating? Did it's fan fail?

I made sure that the one that I bought was ATX with 20pins and had the 4 pin
connector for P4. It does. The only difference between the old one and the
new one is that the new one is 450W and the old one was 300W.

Real 450W or fake 450W?

You can usually make a PSU run without a computer by shorting the green
wire on pin 14 to any black wire, such at pin 13 or 15. If that
doesn't make the PSU fan spin, unplug it and connect a hard drive to
provide a load on the +5.0V rail, and try again.

What brand of PSU is it, and, more importantly, what are its
registration numbers from CSA and UL (under the "9U" or "RU" symbol)?
You can check those numbers at www.csa.ca and www.ul.com to find the
actual manufacturer. If there are no such numbers, then the PSU is
absolute crap.

 

[tom]

How do you know it's overheating? Did it's fan fail?


Real 450W or fake 450W?

You can usually make a PSU run without a computer by shorting the green
wire on pin 14 to any black wire, such at pin 13 or 15. If that
doesn't make the PSU fan spin, unplug it and connect a hard drive to
provide a load on the +5.0V rail, and try again.

What brand of PSU is it, and, more importantly, what are its
registration numbers from CSA and UL (under the "9U" or "RU" symbol)?
You can check those numbers at www.csa.ca and www.ul.com to find the
actual manufacturer. If there are no such numbers, then the PSU is
absolute crap.

The fan on the original isn't working properly and it overheats after about
1 - 2 hours depending on what I am using the PC for.

Both the old model and the new one are Enermax units, which is a reasonable
brand. I'd like to think that if they say it's 450W, it's a real 450W.
Being honest, for all I know it could be a 350W with a 450W label, but I'd
still expect it to do something when I plug it in...

In any case, it's going back tomorrow morning. Thanks for replying.

Tom

 

[Chris Hill]

The fan on the original isn't working properly and it overheats after about
1 - 2 hours depending on what I am using the PC for.

Both the old model and the new one are Enermax units, which is a reasonable
brand. I'd like to think that if they say it's 450W, it's a real 450W.
Being honest, for all I know it could be a 350W with a 450W label, but I'd
still expect it to do something when I plug it in...

In any case, it's going back tomorrow morning. Thanks for replying.

Why not just replace the fan in the one you have? Usually a trivial
exercise.

 

[tom]

Thanks to those who responded to my query.

I took it back today and the supplier tested it and confirmed that the PSU
was faulty. They gave me a replacement and this is now sitting in my PC
working perfectly.

I guess I was just unlucky, but shit happens and if it's the worst thing
that happens to me this week, I'll be grateful.

Thanks again.
Tom

 

[old jon]

Thanks to those who responded to my query.

I took it back today and the supplier tested it and confirmed that the PSU
was faulty. They gave me a replacement and this is now sitting in my PC
working perfectly.

I guess I was just unlucky, but shit happens and if it's the worst thing
that happens to me this week, I'll be grateful.

A very sensible way of looking at real life..

 

[ToolPackinMama]

Thanks to those who responded to my query.

I took it back today and the supplier tested it and confirmed that the PSU
was faulty. They gave me a replacement and this is now sitting in my PC
working perfectly.

Mazeltov.