Computer switches off

"Bobby" wrote in message
...
The power switch on my daughter's PC has been damaged. I managed to "fix"
it
but when I try to switch on it powers-up for a few seconds (about 5
seconds)
before it switches off. Sometimes it doesn't come on at all. But it
usually
attempts to start before switching off.

I'm not sure if this has to do with the power switch or more serious
damage
to the system unit (I don't know what she's done to it).

Can anyone advise?

I'm assuming this is a fairly recent PC and is of the ATX type. The switch
operates by momentarily closing a circuit which activates the motherboard.
I'd say, if it's only staying on for 5 seconds that you have the switch
"fix"ed to stay closed-circuit and it switches on, then switches off again
after four seconds, as if the switch has been pushed and held. (Hard re-set)

Change the switch to be a momentary-contact as it should be and all will be
well. I'd say she hasn't done anything to it, you "fix"ing the switch is
causing the current problem.
--
~misfit~



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Thanks for the advice. Yes, it's a relatively new PC. But the machine
switches *off* - it doesn't reset.

I'm not clear what it is you are suggesting I do. Can you clarify?

Cheers.

Bobby

"~misfit~" wrote in message
...

"Bobby" wrote in message
...
The power switch on my daughter's PC has been damaged. I managed to
"fix"
it
but when I try to switch on it powers-up for a few seconds (about 5
seconds)
before it switches off. Sometimes it doesn't come on at all. But it
usually
attempts to start before switching off.

I'm not sure if this has to do with the power switch or more serious
damage
to the system unit (I don't know what she's done to it).

Can anyone advise?

I'm assuming this is a fairly recent PC and is of the ATX type. The switch
operates by momentarily closing a circuit which activates the motherboard.
I'd say, if it's only staying on for 5 seconds that you have the switch
"fix"ed to stay closed-circuit and it switches on, then switches off again
after four seconds, as if the switch has been pushed and held. (Hard
re-set)

Change the switch to be a momentary-contact as it should be and all will
be
well. I'd say she hasn't done anything to it, you "fix"ing the switch is
causing the current problem.
--
~misfit~



---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.504 / Virus Database: 302 - Release Date: 24/07/2003

He's saying, you may have "fixed it" incorrectly.
Are you real sure that the on/off switch is a momentary
contact one?

"Bobby" wrote in message
...
Thanks for the advice. Yes, it's a relatively new PC. But the
machine
switches *off* - it doesn't reset.

I'm not clear what it is you are suggesting I do. Can you clarify?

Cheers.

Bobby

"~misfit~" wrote in message
...

"Bobby" wrote in message
...
The power switch on my daughter's PC has been damaged. I managed
to
"fix"
it
but when I try to switch on it powers-up for a few seconds
(about 5
seconds)
before it switches off. Sometimes it doesn't come on at all. But
it
usually
attempts to start before switching off.

I'm not sure if this has to do with the power switch or more
serious
damage
to the system unit (I don't know what she's done to it).

Can anyone advise?

I'm assuming this is a fairly recent PC and is of the ATX type.
The switch
operates by momentarily closing a circuit which activates the
motherboard.
I'd say, if it's only staying on for 5 seconds that you have the
switch
"fix"ed to stay closed-circuit and it switches on, then switches
off again
after four seconds, as if the switch has been pushed and held.
(Hard
re-set)

Change the switch to be a momentary-contact as it should be and
all will
be
well. I'd say she hasn't done anything to it, you "fix"ing the
switch is
causing the current problem.
--
~misfit~



---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.504 / Virus Database: 302 - Release Date: 24/07/2003

The switch is a momentary one. Momentary means the contact is made only
momentarily (even if you keep holding down the switch).

I question the last part " even if you keep holding down the switch". As
long as you hold it down, it remains closed. Release it and the switch is
open. I just pulled my test ATX switch and verified this with an ohmmeter
in case the laws of physics changed in the last hour. Vanguard, I just
believe this is a "momentary" (pardon the pun) lapse in your writing skills
as you described the actions of the switch correctly in you post later on.
;^)

The motherboard interprets the switch. Depending on the length of time the
switch is closed, the state the PC is already in and the settings in the
BIOS, the pushing of the switch will turn on the PC, turn off the PC,
suspend or resume, etc.

Have a nice day!


"Vanguard" wrote in message
news:QjyUa.133968$OZ2.25703@rwcrnsc54...
"Bobby" wrote in message

Thanks for the advice. Yes, it's a relatively new PC. But the machine
switches *off* - it doesn't reset.

I'm not clear what it is you are suggesting I do. Can you clarify?


The switch is a momentary one. Momentary means the contact is made only
momentarily (even if you keep holding down the switch). Your fix is a
constant contact. You used the wrong switch type or you simply spliced
the wires together to have a constant short. You didn't tell us what
was your "fix" so we really can only guess, and due to the behavior
after your "fix" we are guessing that you short the wires together
either with a splice or the wrong switch type. Or maybe you stuck in
some chewing gum to constantly push the switch so it makes constant
contact across the wires. 5 seconds is the amount of time the system
will remain powered when the switch is constantly pushed in; i.e., the
power is on, you push the switch, hold it in for 5 seconds, and then the
power goes off. You are expected to push in the button and then RELEASE
it to let the power come and and STAY on.

Note that the power (and reset) buttons are just that, buttons. They
are not the actual switch but only are used to push the stems on the
switches. If the button has been damaged beyond repair (so it won't
slide in and out), you could remove it entirely. You'll then see the
switch in the case against which the button pressed. Usually you can
just manage to push the stem in and out using your fingernail, or you
can use something to push against the stem, like an ear swab
(preferrably a clean one) or plastic pen (with the metal tip removed or
withdrawn) or some other stem-shaped non-conductive object.

If it is the switch itself that is damaged, you really need to have it
replaced.

"rcm" wrote in message
. ca
The switch is a momentary one. Momentary means the contact is made
only momentarily (even if you keep holding down the switch).

I question the last part " even if you keep holding down the switch".
As long as you hold it down, it remains closed. Release it and the
switch is open. I just pulled my test ATX switch and verified this
with an ohmmeter in case the laws of physics changed in the last
hour. Vanguard, I just believe this is a "momentary" (pardon the
pun) lapse in your writing skills as you described the actions of the
switch correctly in you post later on. ;^)

The motherboard interprets the switch. Depending on the length of
time the switch is closed, the state the PC is already in and the
settings in the BIOS, the pushing of the switch will turn on the PC,
turn off the PC, suspend or resume, etc.

Have a nice day!

You're right. The momentary switch for the ATX power is always in
contact as long as you continue to hold down the switch. It is not a
momentary switch of the kind that snaps past a contact to provide a
quick connect and disconnect based on a throw of the switch. However,
to a degree, the electronics makes it a 5-second momentary throw switch:
you hold it down, and 5 seconds later the motherboard will pull the
PS-ON signal to TTL high on the 20-pin Molex connector from the power
supply, and continued holding down of the switch will not cause any
additional effect. You are also right that the switch is "programmable"
in that you can configure within the BIOS what a quick push versus a
long push will do or what any push regardless of length will do. But
with only 5 seconds before the power supply turns off after turning it
on, Bobby isn't going to be able to get into the BIOS to make any
changes.

I suspect the power button (which is not a switch) got damaged by impact
and is no longer usable to push the stem on the switch mounted in the
case. So the fix might've been to glue down the button so it constantly
pushes against the switch stem and keeps the switch constantly closed.
That's one scenario. Anyway, the switch is probably okay and can still
be depressed if you can manage to get your fingernail, ear swab,
popsicle stick, plastic pen, or whatever through the case slot to push
the switch's stem. I do this all the time when I have the case shell
removed since the button is in the then removed front cover (but then I
can easily reach the slot with my finger to use a fingernail to push the
switch stem).



"Vanguard" wrote in message
news:QjyUa.133968$OZ2.25703@rwcrnsc54...
"Bobby" wrote in message

Thanks for the advice. Yes, it's a relatively new PC. But the
machine switches *off* - it doesn't reset.

I'm not clear what it is you are suggesting I do. Can you clarify?


The switch is a momentary one. Momentary means the contact is made
only momentarily (even if you keep holding down the switch). Your
fix is a constant contact. You used the wrong switch type or you
simply spliced the wires together to have a constant short. You
didn't tell us what was your "fix" so we really can only guess, and
due to the behavior after your "fix" we are guessing that you short
the wires together either with a splice or the wrong switch type.
Or maybe you stuck in some chewing gum to constantly push the switch
so it makes constant contact across the wires. 5 seconds is the
amount of time the system will remain powered when the switch is
constantly pushed in; i.e., the power is on, you push the switch,
hold it in for 5 seconds, and then the power goes off. You are
expected to push in the button and then RELEASE it to let the power
come and and STAY on.

Note that the power (and reset) buttons are just that, buttons. They
are not the actual switch but only are used to push the stems on the
switches. If the button has been damaged beyond repair (so it won't
slide in and out), you could remove it entirely. You'll then see the
switch in the case against which the button pressed. Usually you can
just manage to push the stem in and out using your fingernail, or you
can use something to push against the stem, like an ear swab
(preferrably a clean one) or plastic pen (with the metal tip removed
or withdrawn) or some other stem-shaped non-conductive object.

If it is the switch itself that is damaged, you really need to have
it replaced.

"Bobby" wrote in message

I don't know how it started but the switch was "stuck in" - my
solution was to use a penknife to prise it out. It didn't fully
retract but it did "come out" about 3/4 of the way. When I then
connected the power cord it powered up (I didn't use the switch -
just used the power cord to start up the system) - but then switched
off as I described. That's the current position.

Advice appreciated. BTW I'm not competent with electronics so don't
suggest that I replace the switch.


Does the front cover pop off? That is, can you put your fingers
underneath the front and pry off the front cover? If so then you get
behind the button to see if you can then free it up. If it has been
damaged beyond repair, see my other post about how to just get rid of
the button and use a fingernail, ear swab, or whatever to push on the
switch's stem thorugh the slot in the case.

Yes, Vanguard, that makes sense - I think that the switch is making constant
contact - hence the 5 second switch off. What can I do about this?

Cheers.

Bobby

"Vanguard" wrote in message
. net...
"rcm" wrote in message
. ca
The switch is a momentary one. Momentary means the contact is made
only momentarily (even if you keep holding down the switch).

I question the last part " even if you keep holding down the switch".
As long as you hold it down, it remains closed. Release it and the
switch is open. I just pulled my test ATX switch and verified this
with an ohmmeter in case the laws of physics changed in the last
hour. Vanguard, I just believe this is a "momentary" (pardon the
pun) lapse in your writing skills as you described the actions of the
switch correctly in you post later on. ;^)

The motherboard interprets the switch. Depending on the length of
time the switch is closed, the state the PC is already in and the
settings in the BIOS, the pushing of the switch will turn on the PC,
turn off the PC, suspend or resume, etc.

Have a nice day!

You're right. The momentary switch for the ATX power is always in
contact as long as you continue to hold down the switch. It is not a
momentary switch of the kind that snaps past a contact to provide a
quick connect and disconnect based on a throw of the switch. However,
to a degree, the electronics makes it a 5-second momentary throw switch:
you hold it down, and 5 seconds later the motherboard will pull the
PS-ON signal to TTL high on the 20-pin Molex connector from the power
supply, and continued holding down of the switch will not cause any
additional effect. You are also right that the switch is "programmable"
in that you can configure within the BIOS what a quick push versus a
long push will do or what any push regardless of length will do. But
with only 5 seconds before the power supply turns off after turning it
on, Bobby isn't going to be able to get into the BIOS to make any
changes.

I suspect the power button (which is not a switch) got damaged by impact
and is no longer usable to push the stem on the switch mounted in the
case. So the fix might've been to glue down the button so it constantly
pushes against the switch stem and keeps the switch constantly closed.
That's one scenario. Anyway, the switch is probably okay and can still
be depressed if you can manage to get your fingernail, ear swab,
popsicle stick, plastic pen, or whatever through the case slot to push
the switch's stem. I do this all the time when I have the case shell
removed since the button is in the then removed front cover (but then I
can easily reach the slot with my finger to use a fingernail to push the
switch stem).



"Vanguard" wrote in message
news:QjyUa.133968$OZ2.25703@rwcrnsc54...
"Bobby" wrote in message

Thanks for the advice. Yes, it's a relatively new PC. But the
machine switches *off* - it doesn't reset.

I'm not clear what it is you are suggesting I do. Can you clarify?


The switch is a momentary one. Momentary means the contact is made
only momentarily (even if you keep holding down the switch). Your
fix is a constant contact. You used the wrong switch type or you
simply spliced the wires together to have a constant short. You
didn't tell us what was your "fix" so we really can only guess, and
due to the behavior after your "fix" we are guessing that you short
the wires together either with a splice or the wrong switch type.
Or maybe you stuck in some chewing gum to constantly push the switch
so it makes constant contact across the wires. 5 seconds is the
amount of time the system will remain powered when the switch is
constantly pushed in; i.e., the power is on, you push the switch,
hold it in for 5 seconds, and then the power goes off. You are
expected to push in the button and then RELEASE it to let the power
come and and STAY on.

Note that the power (and reset) buttons are just that, buttons. They
are not the actual switch but only are used to push the stems on the
switches. If the button has been damaged beyond repair (so it won't
slide in and out), you could remove it entirely. You'll then see the
switch in the case against which the button pressed. Usually you can
just manage to push the stem in and out using your fingernail, or you
can use something to push against the stem, like an ear swab
(preferrably a clean one) or plastic pen (with the metal tip removed
or withdrawn) or some other stem-shaped non-conductive object.

If it is the switch itself that is damaged, you really need to have
it replaced.

It's just a clone rcm - but I'll have a play with the switch and see what
happens.

"rcm" wrote in message
. ca...
You do not have to be an electronics expert to look at a PC but experience
is a definite asset. Sometimes common sense and some "handyman" expertise
is all that is needed.

From your description, as others have suggested, the mechanics of the
switch
seem compromised. On most systems, the button on the front is directly
over
the switch inside. Consider it direct drive to the switch. In some
computers, like Compaq, IBM, AST brand names, they have convoluted
mechanical mechanisms that push a switch farther inside or in the power
supply farther back. Being mechanical, they can get out of alignment
(rare).

My experience with problems with power switches as I can remember are as
follows:

1) Acer P166 MMX Black tower case. Would not power on. The power switch
in
the front was connected by a rod, bent and shaped in a strange pattern to
snake halfway back to a standard ATX power switch which was on a plate of
thin metal to the case. The end of the rod was connected to the standard
switch with a small rubber tube coupling the ends!!!!!! The plate the
switch was on had slowly bent over time from being at right angles to
being
at 80 degrees or so. This cause the switch to be farther back by a mm or
two or three but enough to not allow contact when the switch was
depressed.
I fixed it by bending the switch plate back to right angles. This was
years
ago and I have seen this design several times and this is a common problem
with this mechanical rod/tube/switch system.

2) AST Pxx Bravo series system. This was a direct connect to the AT
switch
on a plate at a right angle just inside the case. Most switches are on
the
case metal or on the plastic front panel. They are screwed on and cannot
really move. Again, the thin plate bent from being at right angles and
the
switch could not click on unless you really pushed hard. Of course
pushing
hard just bent the plate even more for the next time. Fixed the plate to
right angle again. But these PC had a history of this problem because the
metal was too thin and bent over time.

3) On another note, in older AT systems, the power switch had break off
notches (about 1 mm each) to allow you to have a custom length if needed
on
cases where the front panel was too close. When replacing the power
supply
in these systems, it was possible to have trouble closing up the case
front
panel and even powering on the system. A little common sense and
experience
found the problem and the switch was adjusted to fit right. I also have
used tubing cut to the correct length to lengthen the switch shaft if it
was
too short but placing the tubing over the shaft.

These are all experiences I am relating to you to give you an idea of
possible causes (similar) for your problem. The switch may not be
defective, the mechanics of operating it may be compromised and easily
fixed. If you have any mechanical skills, you might be able to fix it
quite
simply.

Obviously, you may just have a busted switch. Hard to do but not
impossible. Or the spring mechanism is bad. Changing the switch is not
difficult for the experienced tech but for the inexperienced, the
possibility of causing other problems is great. Bring it to a shop, cost
you $50-$100. Hopefully they will be honest. PC repair is like car
repair
shops, they can be expensive and you can be taken for a ride (pun
unintended). Try to get references on the shop from friends and family.

What model of PC do you have? Brand and model and tower or desktop? Or
just a clone???

Hope this food for thought helps.

"Bobby" wrote in message
...
Thanks for the feedback rcm.

How did this problem start? Did you add new hardware or change the
system
somehow or just open the case for a peek? You may have caused the
problem
with a loose connection. Or drop the PC, kick it, etc.

I don't know how it started but the switch was "stuck in" - my solution
was
to use a penknife to prise it out. It didn't fully retract but it did
"come
out" about 3/4 of the way. When I then connected the power cord it
powered
up (I didn't use the switch - just used the power cord to start up the
system) - but then switched off as I described. That's the current
position.

Advice appreciated. BTW I'm not competent with electronics so don't
suggest
that I replace the switch.

Cheers.

Bobby



"rcm" wrote in message
. ca...
How did you fix it???? More details please.

Did you replace the switch? If so, you need to put the correct type
of
switch as other posters mentioned. Old AT system with AT power
supplies
used an On Off switch that worked like a light switch. The light was
on
or
off. Same for a PC. So you can't use an old switch from an old PC.

The ATX system you have works differently. IT does not have an On Off
switch like the above. It is a momentary contact switch. It is just
on
when you push it in and hold it. The power supply/motherboard senses
this
momentary on as a signal to turn on the PC. Holding the switch in
long
enough will signal it to go to sleep or power off. Putting in the
wrong
type of switch like the one above turns it on and right back off.

You can tell if it a momentary switch because it never clicks on. It
just
pushes in and goes right back out. This looks "broken" to people with
no
PC
background but it is normal.

If you did not change the switch, then your power supply is turning
itself
off. Could be a switch problem or a power short or bad component.

How did this problem start? Did you add new hardware or change the
system
somehow or just open the case for a peek? You may have caused the
problem
with a loose connection. Or drop the PC, kick it, etc.


"Bobby" wrote in message
...
The power switch on my daughter's PC has been damaged. I managed to
"fix"
it
but when I try to switch on it powers-up for a few seconds (about 5
seconds)
before it switches off. Sometimes it doesn't come on at all. But it
usually
attempts to start before switching off.

I'm not sure if this has to do with the power switch or more serious
damage
to the system unit (I don't know what she's done to it).

Can anyone advise?

Cheers.

Bobby

"Bobby" wrote in message

Yes, Vanguard, that makes sense - I think that the switch is making
constant contact - hence the 5 second switch off. What can I do about
this?


Can you pop off the front cover (so you can get at the button from the
backside of the cover)? Maybe then you could access it better to free
it up. If not, see if the switch is mounted to the case so its stem is
accessible through a slot. Can you push your fingernail into the slot
to push the stem of the switch to make it power on and off? If you
cannot repair the button, you might be able to remove it and then use
your finger, ear swab, popsicle stick, or whatever to reach through the
hole left in the front cover by the button's removal and push the switch
stem.

The button provided some protection in that its range of motion was
limited. As such, it prevents users from exercising too much force
against the switch's stem. So if you end up having to press against the
stem yourself without anything anymore limiting the range of your push,
be sure to push gently.

Also, if this is a clone, it's possible you could get a replacement
front cover. If it's cheap enough, you could just buy another of the
same case and use the front cover from the new case. That's probably
cheaper than hauling the computer to the local shop to get them to fix
the button (and if it's really damaged, they'll just order a new front
cover or move everything into a new case).