Assembled PC dose not power

  • Thread starter Thread starter Lara
  • Start date Start date
L

Lara

Hello,

I have assembled a PC components in the case but it dose not power
on , I changed the power supply also nothing happened ... what is the
problem ?
Is the problem in the switch button cable ?
How can I sure that this cable is installed correctly?


Thanx,,
 
Lara said:
Hello,

I have assembled a PC components in the case but it dose not power
on , I changed the power supply also nothing happened ... what is the
problem ?
Is the problem in the switch button cable ?
How can I sure that this cable is installed correctly?
Click to expand...


One possibility, check that the connections from the front panel to the
motherboard are correct. One of them is the start up button.
 
Keith Willcocks said:
One possibility, check that the connections from the front panel to the
motherboard are correct. One of them is the start up button.
Click to expand...

Is the jumper for clearing the bios in the right spot?
 
Hello,

I have assembled a PC components in the case but it dose not power
on , I changed the power supply also nothing happened ... what is the
problem ?
Is the problem in the switch button cable ?
How can I sure that this cable is installed correctly?

Thanx,,
Click to expand...

"I have assembled a PC components in the case but.........."
Where did they come from? Like New? 2nd hand etc?
Motherboard likewise? Have you done this before...& did it work/not
work?
Did you follow a m'board drawing/sketch/diagram while building this?
Does anything at ALL move/light up/make a noise/flash or otherwise
look/smell/sound different
than just the second before you hit the t.. switch? No green (or any
colour m'board LED?)
Without answering some questions there are too many variables to
hazard a guess.
starting with..
short on m'board
CPU not sitting right
IDE/power/graphics/video card not seated/socketed correctly.
RAM (as above or incompatible with M'board etc)
What motherboard do you have? Have you or can you get a drawing for
this m'board?
Post as much as you can of the details you can give.
 
Hello,

I have assembled a PC components in the case but it dose not power
on , I changed the power supply also nothing happened ... what is the
problem ?
Is the problem in the switch button cable ?
How can I sure that this cable is installed correctly?


Thanx,,
Click to expand...


With all this information we have to go on, the
possibilities are endless.

Pull out all parts but video, 1 memory module, CPU,
heatsink/fan, then clear CMOS. Unplug the case connectors
and short the two power-on motherboard pins with something
metal.

If it does not work, start over giving us complete but
concise lists of all parts make, model, including PSU make,
model, wattage and 12V current rating.
 
Lara said:
Hello,

I have assembled a PC components in the case but it dose not power
on , I changed the power supply also nothing happened ... what is the
problem ?
Is the problem in the switch button cable ?
How can I sure that this cable is installed correctly?


Thanx,,
Click to expand...

These are the elements needed to switch on the power supply.

----------------- ---------------
| Motherboard | +5VSB | |
| |<-------------| |
Push | | | ATX |
button | | PS_ON# | Power |
+---x x------| PWR |------------->| Supply |
| |(Momentary | | |
+------------| Contact) |------------->| |
| | COM | |
------------------ ---------------

1) When you turn on the power supply at the back, that causes
+5VSB to flow toward the motherboard.
2) On some motherboards, there is a green LED on the motherboard,
and it is a status indicator. If the green LED lights up, that
shows +5VSB is present. You can also check for +5VSB with a
multimeter set to the volts scale, and connected to +5VSB and COM
3) When the user presses the push button on the front of the
computer, that sends a momentary closed switch contact to
the motherboard. The push button is connected to the PANEL
header on the motherboard. The polarity of the push button
cable does not matter. What does matter, is that the push button
cable, is connected to the correct two pins on the PANEL header.
4) When the momentary contact is received by the motherboard,
it is "latched" or stored in the motherboard logic. The motherboard
sends an active low logic signal "PS_ON#" to the power supply.
The voltage value of PS_ON#, when it is trying to turn on the
ATX power supply, is close to 0 volts. When the power supply is
to be switched off, you will find the voltage value on PS_ON# is
near to +5 volts.
5) With the PS_ON# signal pulled close to ground potential (ground = COM),
the PSU starts up, and then the PSU delivers all the other voltages,
like +3.3V, +5V, +12V, -12V and so on. If you hear the fans
spinning in the computer, then you know that +12V is present
inside the computer. Measuring the other voltages with a
multimeter, can verify they are present also.

The computer speaker will beep once, if the initial part of the
Power On Self Test (POST) sequence is going well. If you get that
far, post back any other symptoms you get.

This document defines the pins on a 24 pin type ATX power supply,
so you will know where to make measurements with a multimeter on
the volts scale. See page 37.

http://www.formfactors.org/developer/specs/ATX12V_PSDG_2_2_public_br2.pdf

Paul
 
kony said:
With all this information we have to go on, the
possibilities are endless.

Pull out all parts but video, 1 memory module, CPU,
heatsink/fan, then clear CMOS. Unplug the case connectors
and short the two power-on motherboard pins with something
metal.

If it does not work, start over giving us complete but
concise lists of all parts make, model, including PSU make,
model, wattage and 12V current rating.
Click to expand...

just to add to the above if you can take a picture of the where the power
switch is connected and attach to post might help
 
Darklight said:
kony wrote:
.... snip ...


just to add to the above if you can take a picture of the where
the power switch is connected and attach to post might help
Click to expand...

Horrors. DO NOT ATTACH binaries (i.e. pictures) to Usenet
messages. If you want to publish them mount them under some
accessible page, and publish the URL.
 
With all this information we have to go on, the
possibilities are endless.

Pull out all parts but video, 1 memory module, CPU,
heatsink/fan, then clear CMOS. Unplug the case connectors
and short the two power-on motherboard pins with something
metal.

If it does not work, start over giving us complete but
concise lists of all parts make, model, including PSU make,
model, wattage and 12V current rating.
Click to expand...

What's up? Did we scare her off? Oh, dear! :-)
 
Paul said:
These are the elements needed to switch on the power supply.

----------------- ---------------
| Motherboard | +5VSB | |
| |<-------------| |
Push | | | ATX |
button | | PS_ON# | Power |
+---x x------| PWR |------------->| Supply |
| |(Momentary | | |
+------------| Contact) |------------->| |
| | COM | |
------------------ ---------------
Click to expand...


Come on CB - you will need to reply to this using your usual red pen,
surely?
 
Lara said:
Hello,

I have assembled a PC components in the case but it dose not power
on , I changed the power supply also nothing happened ... what is the
problem ?
Click to expand...

Well its either 2 faulty power supplies or something else.
Is the problem in the switch button cable ?
Click to expand...

Could be - why not just touch the motherboard connector for the power supply
with a small screwdriver and eliminate the power switch from enquiries.
Watch out for static though or w_tom will be on your back!
How can I sure that this cable is installed correctly?
Click to expand...

Look at it and if it is in the right place then it is installed correctly!
There are only 2 wires and the manual will tell you where they should be
plugged in (the 2 pins I just talked about shorting with a screwdriver).

You haven't replied to any of the replies here. We have all said that you
have not given us enough to go on, so you need to tell us more information.
What exatly does happen when you press the power button - do any fans spin
(even for a moment)? Does the speaker beep? Do you have any USB power? To
check this - do you have any USB devices with LEDs on? If you plug them in
while the PC is plugged in, do their LEDs light?
 
Come on CB - you will need to reply to this using your usual red pen,
surely?
Click to expand...

This is a reminder that I want a newsreader that recognizes
when something is ASCII art and uses fixed fonts only for
the ASCII-art.
 
What's up? Did we scare her off? Oh, dear! :-)
Click to expand...

We can hope that what has been suggested so far is being
tried and reported, so we have a better idea of what's going
on. Sometimes it's easy for people to forget that only they
can see the system in front of them.
 
CBFalconer said:
Horrors. DO NOT ATTACH binaries (i.e. pictures) to Usenet
messages. If you want to publish them mount them under some
accessible page, and publish the URL.
Click to expand...

God forbid that we should move forward! Lets stick in the 80s - its much
safer here!
 
GT said:
God forbid that we should move forward! Lets stick in the 80s -
its much safer here!
Click to expand...

This is a stupid attitude. If you want binaries, there are binary
newsgroups available. You can identify them by the word 'binary'
in their name. However Usenet is a pure text mechanism, and
doesn't need blocking with garbage, of interest to very few.
 
CBFalconer said:
This is a stupid attitude. If you want binaries, there are binary
newsgroups available. You can identify them by the word 'binary'
in their name. However Usenet is a pure text mechanism, and
doesn't need blocking with garbage, of interest to very few.
Click to expand...

So tell us, which binary newsgroup should Lara (OP) use to post an image
relevant to this thread post? And don't you think the users of that group
are going to get fed up with us hardware guys posting off-topic images from
time to time?!?

Sure there are binary newsgroups - they deal primarily in binary posts and
uploads, but are not limited purely to binary - there is some text and
conversations that take place.

This is a text-based newsgroup - it deals primarily in textual posts, but I
don't see why it has to be limited to purely text. Can you please explain to
everyone why an image of a power connector in a thread concerning a power
connector could possible be considered garbage, of interest to very few?
 
GT said:
This is a text-based newsgroup - it deals primarily in textual posts, but
I don't see why it has to be limited to purely text. Can you please
explain to everyone why an image of a power connector in a thread
concerning a power connector could possible be considered garbage, of
interest to very few?
Click to expand...

Because many usenet servers, paid or free, strip binaries out of non-binary
groups (as they should).

Seriously, you're tilting at windmills here. Binaries do not belong in
non-binary groups, as a convention, period.

Jon
 
Jon Danniken said:
Because many usenet servers, paid or free, strip binaries out of
non-binary groups (as they should).

Seriously, you're tilting at windmills here. Binaries do not belong in
non-binary groups, as a convention, period.
Click to expand...

'tilting at windmills' - is that a quote from the 80s? I think the cheap or
free newsgroup servers strip out binaries to save themselves storage space
and maintenance, rather than to comply with these superceeded views!

We are so far off topic now that we should agree to disagree and stop.
 
thank you to all of you,,

Sorry if i'm late , the reason is my work..

Today , I tried again to change power supply then only the power
supply fan and processor fan are power on for a second then suddenly
these fans are stop and I faced the same problem again nothing
happened when I press the power button,,
 
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