For some time by system would have a hard time starting and would click on
and off many times while holding the button in. It would finally start after
some time but now it seems to be dead. I tried shorting out the wires on the
main board where the button was plugged in and finally replaced the PS with
an Antec 500 W but no power seems to be getting any where. I am thinking of
replacing the CPU next as I have no idea what would cause this problem. Can
anyone off any help on where I might look for a fix? I use D915PBL Desktop
board LGA 775 with 3 G dual processor CPU.
Jonathan wrote:
> For some time by system would have a hard time starting and would
> click on and off many times while holding the button in. It would
> finally start after some time but now it seems to be dead. I tried
> shorting out the wires on the main board where the button was plugged
> in and finally replaced the PS with an Antec 500 W but no power seems
> to be getting any where. I am thinking of replacing the CPU next as I
> have no idea what would cause this problem. Can anyone off any help
> on where I might look for a fix? I use D915PBL Desktop board LGA 775
> with 3 G dual processor CPU.
> Thanks for any help.
If I were you, I would take it to a PC repairers.
--
SteveH
Jonathan wrote:
> For some time by system would have a hard time starting and would click on
> and off many times while holding the button in. It would finally start after
> some time but now it seems to be dead. I tried shorting out the wires on the
> main board where the button was plugged in and finally replaced the PS with
> an Antec 500 W but no power seems to be getting any where. I am thinking of
> replacing the CPU next as I have no idea what would cause this problem. Can
> anyone off any help on where I might look for a fix? I use D915PBL Desktop
> board LGA 775 with 3 G dual processor CPU.
>
> Thanks for any help.
>
Power ------------ Motherboard Logic -------------- Power Supply
Button (converts momentary (PSON# controls the
(front of switch closure, to steady state of the main
computer) 0 volt level on PSON#) section of the supply)
The CPU is not in that chain of logic, so replacing the CPU should not change
anything. The motherboard, or the power switch, are other elements that affect
system powerup.
A bad power cable or bad wall outlet, may also play a part.
You can also do a visual inspection inside the computer, and see if all
cables are firmly in place. Check that the CPU heatsink/fan clip is
still secure and the heatsink has not fallen off. And that the CPU fan
cable is plugged in. And so on. You might see something while you have
a look around.
"Paul" <nospam@needed.com> wrote in message
news:g7cf57$lqj$1@aioe.org
> Jonathan wrote:
>> For some time by system would have a hard time starting
>> and would click on and off many times while holding the
>> button in. It would finally start after some time but
>> now it seems to be dead. I tried shorting out the wires
>> on the main board where the button was plugged in and
>> finally replaced the PS with an Antec 500 W but no power
>> seems to be getting any where. I am thinking of
>> replacing the CPU next as I have no idea what would
>> cause this problem. Can anyone off any help on where I
>> might look for a fix? I use D915PBL Desktop board LGA
>> 775 with 3 G dual processor CPU.
>> Thanks for any help.
>>
>
> Power ------------ Motherboard Logic
> -------------- Power Supply Button (converts momentary
> (PSON# controls the
> (front of switch closure, to steady state of the main
> computer) 0 volt level on
> PSON#) section of the supply)
> The CPU is not in that chain of logic, so replacing the
> CPU should not change anything. The motherboard, or the
> power switch, are other elements that affect system
> powerup.
> A bad power cable or bad wall outlet, may also play a
> part.
> You can also do a visual inspection inside the computer,
> and see if all cables are firmly in place. Check that the CPU
> heatsink/fan clip is still secure and the heatsink has not fallen off. And
> that the CPU fan cable is plugged in. And so on. You might see something
> while you have a look around.
>
> Paul
Thanks for the reply Paul.
I have been inspecting everything endlessly and see nothing wrong. I have
unplugged every cable and plugged them in several times. I do have extra
cables with this new PS but I don't see anywhere they would go. I have 4
PCI-E 6 wire cables, 3 black and 3 yellow. One I have plugged into my video
card. I have extra SATA power cables and one extra 6 wire cable that has 3
black and 3 yellow one yellow has a black stripe but no where to plug it
into. I have one 6 wire connector that can only plug into one place with a 4
connector next to in that also can only fit on one connector. It seems like
I am not missing anything but still no power. This system had been running
for a few years undisturbed so I know nothing came loose. The power on
problem just started within the last few months so I am totally lost as to
what might have gone wrong. I just don't trust anyone to not rip me off with
some outrageous repair bill. Who knows how long it might take some unknown
hack to even find a reliable fix. I could replace the MOBO for less that
what I might get a bill for if I am not mistaken. I was hoping there was
someone that knew something that I might have missed.
On Wed, 06 Aug 2008 04:03:38 -0400, Jonathan wrote:
> For some time by system would have a hard time starting and would click
> on and off many times while holding the button in. It would finally
> start after some time but now it seems to be dead. I tried shorting out
> the wires on the main board where the button was plugged in and finally
> replaced the PS with an Antec 500 W but no power seems to be getting any
> where. I am thinking of replacing the CPU next as I have no idea what
> would cause this problem. Can anyone off any help on where I might look
> for a fix? I use D915PBL Desktop board LGA 775 with 3 G dual processor
> CPU.
>
> Thanks for any help.
I think Paul is correct, if you have checked all the connections it is
probably either the power switch or motherboard . You should be able to
test the old psu out of the case to see if it powers up and if you have a
multimeter can check some voltages. Of course you do this at your own
risk.
Here is a website to explain how to test a psu: http://modtown.co.uk/mt/article2.php?id=psumod
Jonathan wrote:
> "Paul" <nospam@needed.com> wrote in message
> news:g7cf57$lqj$1@aioe.org
>> Jonathan wrote:
>>> For some time by system would have a hard time starting
>>> and would click on and off many times while holding the
>>> button in. It would finally start after some time but
>>> now it seems to be dead. I tried shorting out the wires
>>> on the main board where the button was plugged in and
>>> finally replaced the PS with an Antec 500 W but no power
>>> seems to be getting any where. I am thinking of
>>> replacing the CPU next as I have no idea what would
>>> cause this problem. Can anyone off any help on where I
>>> might look for a fix? I use D915PBL Desktop board LGA
>>> 775 with 3 G dual processor CPU.
>>> Thanks for any help.
>>>
>> Power ------------ Motherboard Logic
>> -------------- Power Supply Button (converts momentary
>> (PSON# controls the
>> (front of switch closure, to steady state of the main
>> computer) 0 volt level on
>> PSON#) section of the supply)
>> The CPU is not in that chain of logic, so replacing the
>> CPU should not change anything. The motherboard, or the
>> power switch, are other elements that affect system
>> powerup.
>> A bad power cable or bad wall outlet, may also play a
>> part.
>> You can also do a visual inspection inside the computer,
>> and see if all cables are firmly in place. Check that the CPU
>> heatsink/fan clip is still secure and the heatsink has not fallen off. And
>> that the CPU fan cable is plugged in. And so on. You might see something
>> while you have a look around.
>>
>> Paul
>
> Thanks for the reply Paul.
>
> I have been inspecting everything endlessly and see nothing wrong. I have
> unplugged every cable and plugged them in several times. I do have extra
> cables with this new PS but I don't see anywhere they would go. I have 4
> PCI-E 6 wire cables, 3 black and 3 yellow. One I have plugged into my video
> card. I have extra SATA power cables and one extra 6 wire cable that has 3
> black and 3 yellow one yellow has a black stripe but no where to plug it
> into. I have one 6 wire connector that can only plug into one place with a 4
> connector next to in that also can only fit on one connector. It seems like
> I am not missing anything but still no power. This system had been running
> for a few years undisturbed so I know nothing came loose. The power on
> problem just started within the last few months so I am totally lost as to
> what might have gone wrong. I just don't trust anyone to not rip me off with
> some outrageous repair bill. Who knows how long it might take some unknown
> hack to even find a reliable fix. I could replace the MOBO for less that
> what I might get a bill for if I am not mistaken. I was hoping there was
> someone that knew something that I might have missed.
>
> Thanks.
>
> J.
>
So the Antec supply is not starting at all ? And the old one would click on
and off, while the power button was held down ?
I guess you've already ruled out the power switch, by connecting the
pins together momentarily, on the PANEL header.
To turn on a supply, you can connect PSON# to COM, while the main power
connector is plugged into the motherboard. This bypasses the chain of logic
I just drew. PSON# is supposed to be driven with open collector logic from
the motherboard, and open collector logic is a logic type, that can safely
be grounded. (The logic gate only drives strongly to ground, and doesn't
drive a logic 1. A pullup resistor is used to make a logic 1. The signal
can be grounded, without fear of damaging the logic gate.)
See the diagram for the main ATX connector, to identify PSON# and COM. PSON#
should be a green wire, on the latch side of the connector. There are several
black COM (ground) wires in the vicinity of the green wire. Since some metal from
each pin, is visible from the backside of the connector, you should be able to
access those two connections with a paper clip or something similar. These
two documents show pinout, for a 20 pin and a 24 pin ATX power supply, respectively.
Now, it is only fair to warn about the consequences of this kind of
experiment. On the one hand, connecting a paper clip from PSON# to COM,
will not damage the motherboard gate driving PSON#. But the motherboard
contains features for protecting stuff. An example, is CPU overheating.
If the CPU gets too hot (say the heatsink falls off, as they sometimes
do when some plastic fails), a signal is sent to the motherboard logic
and it turns off the ATX PSU. If you use the "paper clip trick", not
only will it turn on the ATX supply, it will also defeat the CPU
overheat protection feature. That is because, if the CPU overheats,
the motherboard stops driving the PSON# signal - but the paper
clip grounding the supply, is still holding the signal in its
active state (grounded) and the power supply continues to run. So the
CPU will continue to get hotter. So there is a tiny risk associated with
the technique, and bypassing the motherboard logic with a paper
clip, is not what I would consider a safe long term workaround.
If the experiment succeeds and the computer is fully functional, then
you might conclude that the motherboard PSON# driver has a problem. Because
you've tried a second power supply, and the motherboard had no better luck
talking to it, than the original supply.
jerry wrote:
> On Wed, 06 Aug 2008 04:03:38 -0400, Jonathan wrote:
>
>> For some time by system would have a hard time starting and would click
>> on and off many times while holding the button in. It would finally
>> start after some time but now it seems to be dead. I tried shorting out
>> the wires on the main board where the button was plugged in and finally
>> replaced the PS with an Antec 500 W but no power seems to be getting any
>> where. I am thinking of replacing the CPU next as I have no idea what
>> would cause this problem. Can anyone off any help on where I might look
>> for a fix? I use D915PBL Desktop board LGA 775 with 3 G dual processor
>> CPU.
>>
>> Thanks for any help.
>
> I think Paul is correct, if you have checked all the connections it is
> probably either the power switch or motherboard . You should be able to
> test the old psu out of the case to see if it powers up and if you have a
> multimeter can check some voltages. Of course you do this at your own
> risk.
> Here is a website to explain how to test a psu:
> http://modtown.co.uk/mt/article2.php?id=psumod
>
> and another to identify the pins on the psu:
> http://en.wikipedia.org/wiki/ATX
>
> I was always told to put a load on the psu, e.g. an old hard drive. I
> don't know if this is still necessary with the newer psus.
>
> By all means do it safely, and if you are uncomfortable learn more about
> the procedure first.
>
> I assume there are no beeps or any other symptoms when you do try to
> power up the computer.
>
> Good luck
> Jerry
You can also do this, with the power supply connected to the computer.
This picture shows a wire on the bottom of the connector, but you can also
plug a wire into the top side of the connector, while the connector
is plugged into the motherboard. At least one guy, is running his
motherboard that way :-) I don't really like the idea for long
term usage, but for testing, I think it is OK. As long as you've
verified things like the CPU cooling is working and heatsink
is firmly in place.
"Paul" <nospam@needed.com> wrote in message
news:g7db9k$ad1$1@aioe.org
> Jonathan wrote:
>> "Paul" <nospam@needed.com> wrote in message
>> news:g7cf57$lqj$1@aioe.org
>>> Jonathan wrote:
>>>> For some time by system would have a hard time starting
>>>> and would click on and off many times while holding the
>>>> button in. It would finally start after some time but
>>>> now it seems to be dead. I tried shorting out the wires
>>>> on the main board where the button was plugged in and
>>>> finally replaced the PS with an Antec 500 W but no
>>>> power seems to be getting any where. I am thinking of
>>>> replacing the CPU next as I have no idea what would
>>>> cause this problem. Can anyone off any help on where I
>>>> might look for a fix? I use D915PBL Desktop board LGA
>>>> 775 with 3 G dual processor CPU.
>>>> Thanks for any help.
>>>>
>>> Power ------------ Motherboard Logic
>>> -------------- Power Supply Button (converts
>>> momentary (PSON# controls the
>>> (front of switch closure, to steady state of the main
>>> computer) 0 volt level on
>>> PSON#) section of the supply)
>>> The CPU is not in that chain of logic, so replacing the
>>> CPU should not change anything. The motherboard, or the
>>> power switch, are other elements that affect system
>>> powerup.
>>> A bad power cable or bad wall outlet, may also play a
>>> part.
>>> You can also do a visual inspection inside the computer,
>>> and see if all cables are firmly in place. Check that
>>> the CPU heatsink/fan clip is still secure and the
>>> heatsink has not fallen off. And that the CPU fan cable
>>> is plugged in. And so on. You might see something while
>>> you have a look around.
>>> Paul
>>
>> Thanks for the reply Paul.
>>
>> I have been inspecting everything endlessly and see
>> nothing wrong. I have unplugged every cable and plugged
>> them in several times. I do have extra cables with this
>> new PS but I don't see anywhere they would go. I have 4
>> PCI-E 6 wire cables, 3 black and 3 yellow. One I have
>> plugged into my video card. I have extra SATA power
>> cables and one extra 6 wire cable that has 3 black and 3
>> yellow one yellow has a black stripe but no where to
>> plug it into. I have one 6 wire connector that can only
>> plug into one place with a 4 connector next to in that
>> also can only fit on one connector. It seems like I am
>> not missing anything but still no power. This system had
>> been running for a few years undisturbed so I know
>> nothing came loose. The power on problem just started
>> within the last few months so I am totally lost as to
>> what might have gone wrong. I just don't trust anyone to
>> not rip me off with some outrageous repair bill. Who
>> knows how long it might take some unknown hack to even
>> find a reliable fix. I could replace the MOBO for less
>> that what I might get a bill for if I am not mistaken. I
>> was hoping there was someone that knew something that I
>> might have missed.
>> Thanks.
>>
>> J.
>>
>
> So the Antec supply is not starting at all ? And the old
> one would click on and off, while the power button was held down ?
>
> I guess you've already ruled out the power switch, by
> connecting the pins together momentarily, on the PANEL header.
>
> To turn on a supply, you can connect PSON# to COM, while
> the main power connector is plugged into the motherboard. This bypasses
> the chain of logic I just drew. PSON# is supposed to be driven with open
> collector logic from the motherboard, and open collector logic is a logic
> type, that can safely be grounded. (The logic gate only drives strongly to
> ground, and doesn't drive a logic 1. A pullup resistor is used to make a
> logic 1. The signal can be grounded, without fear of damaging the logic
> gate.)
>
> See the diagram for the main ATX connector, to identify
> PSON# and COM. PSON# should be a green wire, on the latch side of the
> connector. There are several black COM (ground) wires in the vicinity of
> the green
> wire. Since some metal from each pin, is visible from the
> backside of the connector, you should be able to access
> those two connections with a paper clip or something
> similar. These two documents show pinout, for a 20 pin and a 24 pin ATX
> power supply, respectively.
> http://www.formfactors.org/developer...X12V_1_3dg.pdf
> (page 30)
> http://www.formfactors.org/developer...public_br2.pdf
> (page 37)
> Now, it is only fair to warn about the consequences of
> this kind of experiment. On the one hand, connecting a paper clip from
> PSON# to COM, will not damage the motherboard gate driving PSON#. But
> the motherboard contains features for protecting stuff. An example, is
> CPU overheating. If the CPU gets too hot (say the heatsink falls off, as
> they sometimes do when some plastic fails), a signal is sent to the
> motherboard logic and it turns off the ATX PSU. If you use the "paper clip
> trick", not only will it turn on the ATX supply, it will also defeat
> the CPU overheat protection feature. That is because, if the CPU
> overheats, the motherboard stops driving the PSON# signal - but the
> paper clip grounding the supply, is still holding the signal in
> its active state (grounded) and the power supply continues to
> run. So the CPU will continue to get hotter. So there is a tiny risk
> associated with the technique, and bypassing the motherboard logic with a
> paper clip, is not what I would consider a safe long term
> workaround.
> If the experiment succeeds and the computer is fully
> functional, then you might conclude that the motherboard PSON# driver has
> a problem. Because you've tried a second power supply, and the motherboard
> had no better luck talking to it, than the original supply.
>
> Paul
"jerry" <jturba@yahoo.com> wrote in message
news:FYpmk.3486$zv7.1213@flpi143.ffdc.sbc.com
> On Wed, 06 Aug 2008 04:03:38 -0400, Jonathan wrote:
>
>> For some time by system would have a hard time starting
>> and would click on and off many times while holding the
>> button in. It would finally start after some time but
>> now it seems to be dead. I tried shorting out the wires
>> on the main board where the button was plugged in and
>> finally replaced the PS with an Antec 500 W but no power
>> seems to be getting any where. I am thinking of
>> replacing the CPU next as I have no idea what would
>> cause this problem. Can anyone off any help on where I
>> might look for a fix? I use D915PBL Desktop board LGA
>> 775 with 3 G dual processor CPU.
>>
>> Thanks for any help.
>
> I think Paul is correct, if you have checked all the
> connections it is probably either the power switch or
> motherboard . You should be able to test the old psu out
> of the case to see if it powers up and if you have a
> multimeter can check some voltages. Of course you do this
> at your own risk.
> Here is a website to explain how to test a psu:
> http://modtown.co.uk/mt/article2.php?id=psumod
>
> and another to identify the pins on the psu:
> http://en.wikipedia.org/wiki/ATX
>
> I was always told to put a load on the psu, e.g. an old
> hard drive. I don't know if this is still necessary with
> the newer psus.
>
> By all means do it safely, and if you are uncomfortable
> learn more about the procedure first.
>
> I assume there are no beeps or any other symptoms when
> you do try to power up the computer.
>
> Good luck
> Jerry
Thanks Jerry. I just noticed while looking inside in low light that there is
a green light on somewhere on the board. I will be looking closer later this
afternoon.
On 2008-08-06, Jonathan <Jonathan@NoSpam.not> wrote:
> For some time by system would have a hard time starting and would click on
> and off many times while holding the button in. It would finally start after
> some time but now it seems to be dead. I tried shorting out the wires on the
> main board where the button was plugged in and finally replaced the PS with
> an Antec 500 W but no power seems to be getting any where. I am thinking of
> replacing the CPU next as I have no idea what would cause this problem. Can
> anyone off any help on where I might look for a fix? I use D915PBL Desktop
> board LGA 775 with 3 G dual processor CPU.
As others have noted, the mobo is a likely culprit. The CPU is
not something I would consider likely at all. Have you tried
reducing the machine to its bare essentials - mobo, CPU, one stick
of memory and video card? Disconnect both the signal and power
from any drives and remove any additonal expansion cards. Obviously
in that state it won't be able to boot but it should come up and
start driving the display.
A few months back I had similar symptoms from a machine that had
been stuffed full of USB and Firewire cards simply because they
were lying around. Reduce the complement to a sane amount and
suddenly the machine sprang back into life which shows reducing
things to the essentials often helps.
Another thing I'd check for before replacing components is for any
shorts between the mobo and the case. If assembled correctly in
the first instance this shouldn't really be an issue but it's
possible a lost screw or whatever inside the machine is causing
the problems. If the machine wasn't compentently assembled in the
first instance another thing to watch is the PCB mounting holes -
you don't need to support _every_ hole, and some boards you
_shouldn't_ support the board at some locations unless using
insulated moutings.
Computer no longer starts 
Linear Mode
