Charge from monitor causing pc to not POST

January 23, 2019 at 10:47:17
Specs: Windows 7
I had a problem getting one of my computers to POST (Power On Self Test) because I had the monitor plugged in and there was still a charge in the vga+power cable while it was connected to the computer. The problem started when I unplugged the computers power cable but left the vga monitor cable in the PC. Then plugged in again. Upon my next try to boot the pc would not POST (Power On Self Test). The fans would come on the hard drive would spin but the keyboard would not turn on and the video would not turn on.
I know it was the monitor because i had this happen before on another computer many years back.

The problem is I do not know how to release the charge correctly. I've tried several different ways to get it to release the charge in the pc.

Powering off the monitor, unplugging it, holding the power button on the pc, etc. I need to know the correct way to release the charge so I don't have to fiddle with it for 30+ minutes. The only way I had gotten it to boot was to remove the ram, booting with 0 sticks, then 1. I also had (on another machine) to remove the CMOS battery and the other computer booted.

All i'm looking for is how to release the charge the right way. Can anyone help?

Thanks.

Horses need not apply.
Horse lover.


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#1
January 23, 2019 at 11:26:23
The chance that the cause of the problem is what you think
it is is practically zero.

How many times has this happened with this computer?

Did you unplug the computer while it was turned on?
I have done that a few times when a computer started
doing something nasty, but it has been very rare.

-- Jeff, in Minneapolis


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#2
January 23, 2019 at 13:54:46
I have to agree with Jeff. I don't know what you did, but having a monitor connected to the computer is not what prevented the system from POSTing. If it was, EVERYONE with a desktop would be having the same problem.

Keep the monitor connected. Unplug the power cord to the tower, then press & hold the power button for at least 20 seconds. Release the button, plug the power cord back in & press the power button to start the PC. If it doesn't work, I suspect your power supply has failed.

message edited by riider


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#3
January 23, 2019 at 17:29:22
I also agree, it does sound more like a bad power supply than anything else.

You have to be a little bit crazy to keep you from going insane.


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#4
January 23, 2019 at 21:50:13
if you were here I could prove it is the charge left from the monitor caused it. Also the way the computers holding a charge and how after unplugging the pc's power cable and leaving the monitor plugged in, Then plugging it back in then trying to reboot caused it.
But anyway if no one else want to share HELPFUL INFO instead of just telling me I don't know what I'm talking about, Please don't post if your not going to help.
Remember what mother always says If you have nothing nice to say keep it to yourself!

Horses need not apply.
Horse lover.


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#5
January 24, 2019 at 00:52:42
"All i'm looking for is how to release the charge the right way. Can anyone help?"

just unplug the power supply cable and hold down the power button for 20seconds or so, no other cables need to be disconnected. (like stated above by riider)

after that just plug the power cable back in and let it start (the machine may try to do some memory training, i.e. restart a few times before you see the post screen again), if it takes longer than 5min, there is some other problem.

i5-6600K[delid]@4.7GHz/4.4GHz cache/@1.395v LLC=6 | 2x4GB Crucial-DDR4-2400CL17@14-15-15-28 1T 3000MHz@1.4v | MSI Armor RX 570 4GB@1410Mhz core@1.2v/1920MHz

message edited by hidde663


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#6
January 24, 2019 at 05:33:40
"if no one else want to share HELPFUL INFO instead of just telling me I don't know what I'm talking about, Please don't post if your not going to help"

I have well over 20 years computer repair experience & I know the others that have responded have many years experience as well. You have been told how to release the residual charge from your system - unplug power cord & hold power button for at least 20 seconds. You haven't told us if you've done that or not.

I can all but guarantee that your problem is NOT related to having a monitor connected to the tower. The fact that fans are spinning & you hear the HDD winding up proves your power supply is producing some power, but it doesn't necessary mean it's producing enough power.

It would help if you'd post the make/model/model number or your system, or the complete system specs (CPU, motherboard, RAM, graphics, power supply, etc). Without knowing what you have, anything we tell you is just a best-guess. If you were to call a mechanic about a problem with your vehicle, the 1st thing you'd be asked is for the year, make, model, engine, etc. Same applies here. The answer(s) you get will only be as good as the details you provide.


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#7
January 24, 2019 at 08:57:34
So-Unfair,

If you think that a static charge could cause the problem, you
could explain why you think so. We know that there is practically
no chance at all that a static charge is the cause.

If you want to find the actual cause, and thus a solution, you need
to take certain steps. I suggested the first two steps: Tell us how
many times this has occurred, and tell us whether you unplugged
the computer while it was running. The answers to those two
questions will greatly narrow down the possibilities.

The number of times the problem has occurred can be roughly
divided into two categories:

1) It happened only once.
2) It has happened several times.

If it happened only once, that suggests that you might have
damaged something when you unplugged the computer while
it was running. Hence the second question. If you did not
unplug the computer or otherwise cut off power while it was
running, then we can look at other possibilities.

If it happened several times, then you may have observed
something that will provide a clue to the cause. In that case,
you would need to describe in more detail the conditions
under which the problem occurred, as well as the system
info that riider asked for.

Given the very limited info you have provided, I agree with
riider and Fingers that the most likely cause is an
under-performing power supply. But we need more info to
make that anything more than a wild guess.

-- Jeff, in Minneapolis


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#8
January 26, 2019 at 14:31:17
Hi So,

is the Monitor powered from the PSU in the PC or direct from a Wall Socket?

Here is an example of one:
https://www.dreamstime.com/stock-ph...

Good Luck - Keep us posted.?

message edited by Mike Newcomb


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#9
January 28, 2019 at 11:02:32
I never said anything about static charge.
I'm talking about the way a computer stores a charge of electricity in it's capacitors and how it has a few different modes of when its powered off and on.

For example (Powering on):
1.)When you plug in the computers power cable to the psu (Power Supply Unit) and it turns on just by plugging it in, not touching the power button. That's 1 way.
2.)When you plug in the power cord but the computer does not turn on (which it's suppose to do).

Shutting off:
1.)One press on the power button shuts the computer off normally.
2.)Or having to PRESS AND HOLD the power button because the computer has hung or because this is one of the "modes" that it turns off.
3.)Shutting off power by pulling the power cable from the power supply.

If you do this without shutting the power off to the monitor (on some monitors) the amber "mode" the monitor is in still has a charge in it and if the vga cable is still connected to it there will still be electricity going to the Desktop via the vga port. You can prove this to yourself. When there's no video attached it will say "no signal" if the power is off or the cable isn't connected to the PC. When it goes into "sleep mode" it still is "on" and there's still a charge going from the monitors vga port to the vga connector in the back of the computer. This is true and you can test it yourself: Take a monitor keep the vga cable disconnected until it says "no signal." Then take it and plug it into a working computer that is off but is still plugged into the wall socket, it will turn "amber" after you keep it plugged in the vga port. It will turn black without the "no signal" message.

Whey does this do this? Because the way the computer is holding a charge inside of it and how it handles electrical charges in it.

Horses need not apply.
Horse lover.

message edited by So-Unfair


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#10
January 28, 2019 at 12:33:49
So-Unfair wrote:

> I never said anything about static charge.

I used the term "static charge" to make clear that a
static electric charge is what you were referring to.

> I'm talking about the way a computer stores a charge of
> electricity in it's capacitors ...

Which confirms that you were talking about a static charge.
Capacitors work by building up a temporary static charge,
and then releasing the charge as an electric current.

> ... and how it has a few different modes of when its
> powered off and on.
>
> For example (Powering on):
> 1.)When you plug in the computers power cable to the psu
> (Power Supply Unit) and it turns on just by plugging it in, not
> touching the power button. That's 1 way.

Do you have, or have you seen a computer that does this?
I'd be interested to know the make and model.

I think it is common for a computer in a standby mode to come
on when it is plugged in, but not a computer that is "off".

> 2.)When you plug in the power cord but the computer does
> not turn on (which it's suppose to do).

All personal computers I've seen in the last 40 years power-on
only when the power switch is in the on position (pre-Windows
computers) or when a momentary-contact button is pressed
(nearly all computers made in the last 25 years).

> Shutting off:
> 1.)One press on the power button shuts the computer off normally.
> 2.)Or having to PRESS AND HOLD the power button because the
> computer has hung or because this is one of the "modes" that it turns off.
> 3.)Shutting off power by pulling the power cable from the power supply.
>
> If you do this without shutting the power off to the monitor (on some
> monitors) the amber "mode" the monitor is in still has a charge in it
> and if the vga cable is still connected to it there will still be electricity
> going to the Desktop via the vga port. You can prove this to yourself.
> When there's no video attached it will say "no signal" if the power is
> off or the cable isn't connected to the PC. When it goes into "sleep
> mode" it still is "on" and there's still a charge going from the monitors
> vga port to the vga connector in the back of the computer.

Here you use the word "charge" in a non-standard way which makes
me suspect that you don't know the difference between a charge and
a current. If something is "going from" the monitor to the computer,
it is a current, not a charge. You may have meant "current" when you
said "charge". Also, such a current could be caused by a charge in a
capacitor, and that appears to be what you meant.

Also, you say:

> ... there will still be electricity going to the Desktop via the vga port.
...
> there's still a charge going from the monitors vga port to the vga
> connector in the back of the computer.

The fact that the "No signal" message does not appear when the
computer is in sleep mode shows that a current is going from the
computer to the monitor through the VGA cable, not from the
monitor to the computer.

> This is true and you can test it yourself: Take a monitor keep the vga
> cable disconnected until it says "no signal." Then take it and plug it
> into a working computer that is off but is still plugged into the wall
> socket, it will turn "amber" after you keep it plugged in the vga port.
> It will turn black without the "no signal" message.

Right. This shows that an electric current goes from the computer to
the monitor over the VGA cable, telling the monitor that the computer
is in Sleep mode.

> Why does this do this? Because the way the computer is holding a
> charge inside of it and how it handles electrical charges in it.

Charges aren't involved with that. Just currents.

-- Jeff, in Minneapolis


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