hard wire power plug

  • Thread starter Thread starter zirath
  • Start date Start date
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zirath

We recently got an IBM 9511-AG4 lcd monitor. The power jack on the monitor
wasn't making good contact and finally stopped functioning. After looking at
the board that the jack is install on, I found 4 pins that seemed to be for
the jack. 3 of the pins were grounding and the 4th wasn't. I was thinking of
connecting the + wire from the ac adapter to the 4th pin and the - wire to a
ground.

Would this be safe?

Thanks.
 
zirath said:
We recently got an IBM 9511-AG4 lcd monitor. The power jack on the monitor
wasn't making good contact and finally stopped functioning. After looking at
the board that the jack is install on, I found 4 pins that seemed to be for
the jack. 3 of the pins were grounding and the 4th wasn't. I was thinking of
connecting the + wire from the ac adapter to the 4th pin and the - wire to a
ground.

Would this be safe?

Thanks.
Click to expand...

On a laptop, the jack might look like this. They actually have a switch
inside the jack, that is sensitive to the presence of the barrel of the
power supply. On an LCD monitor, they wouldn't need that, so the jack style
could be different. Or, they could use one with the switch, and simply not
connect electrically to the extra terminal.

http://www.cui.com/pdffiles/PJ1-021.pdf

The first thing you'd check, is whether the plug is "center positive"
or "center negative". For barrel connectors, this is supposed to be
marked in the plastic, near the jack. That will help ensure that you do
the right thing with respect to the center pin.

You'll notice in that PDF, that terminal 1 is the center pin terminal.
So whatever polarity is marked in the plastic, is the wire you'd
connect to "1".

For the other connection, you need to figure out how the jack works,
whether it is a simple power connection (it should be, on a monitor).
Some of the pieces of metal on a connector, can be there for
mechanical rigidity, rather than an electrical connection. Maybe the
copper patterns on the PCB, will give some hint as to where the
power flows. Getting the center pin polarity right, will reduce
(but not eliminate) the risk of blowing the thing up.

There are all sorts of minor variations on these things, as can be
seen in some of the pictures here.

http://dkc3.digikey.com/PDF/T081/P0438.pdf

Paul
 
We recently got an IBM 9511-AG4  lcd monitor. The power jack on the monitor
wasn't making good contact and finally stopped functioning. After looking at
the board that the jack is install on, I found 4 pins that seemed to be for
the jack. 3 of the pins were grounding and the 4th wasn't. I was thinking of
connecting the + wire from the ac adapter to the 4th pin and the - wire toa
ground.

Would this be safe?

Thanks.
Click to expand...



If done properly, sure. You'd need to determine for sure what goes to
where, and use some kind of cord grip. I'd definitely recommend a plug
& socket in the cord near the monitor, otherwise a pull on the cord
could cause a lot of damage.


NT
 
Paul said:
On a laptop, the jack might look like this. They actually have a switch
inside the jack, that is sensitive to the presence of the barrel of the
power supply. On an LCD monitor, they wouldn't need that, so the jack
style
could be different. Or, they could use one with the switch, and simply not
connect electrically to the extra terminal.

http://www.cui.com/pdffiles/PJ1-021.pdf

The first thing you'd check, is whether the plug is "center positive"
or "center negative". For barrel connectors, this is supposed to be
marked in the plastic, near the jack. That will help ensure that you do
the right thing with respect to the center pin.

You'll notice in that PDF, that terminal 1 is the center pin terminal.
So whatever polarity is marked in the plastic, is the wire you'd
connect to "1".

For the other connection, you need to figure out how the jack works,
whether it is a simple power connection (it should be, on a monitor).
Some of the pieces of metal on a connector, can be there for
mechanical rigidity, rather than an electrical connection. Maybe the
copper patterns on the PCB, will give some hint as to where the
power flows. Getting the center pin polarity right, will reduce
(but not eliminate) the risk of blowing the thing up.

There are all sorts of minor variations on these things, as can be
seen in some of the pictures here.

http://dkc3.digikey.com/PDF/T081/P0438.pdf

Paul
Click to expand...

I found a 2 pin plug socket (don't know if it's called a "sata" plug), on
the side
of the power plug board that gives the same readings on the ohm meter as the
power plug (when the pluig is in - turning on the switch). It gives a ground
reading on one pin and shows a capacitor on the other that charges to the
same amount of resistance.

I was wondering if this might be a back-up plug for the power
 
zirath said:
I found a 2 pin plug socket (don't know if it's called a "sata" plug), on
the side
of the power plug board that gives the same readings on the ohm meter as the
power plug (when the pluig is in - turning on the switch). It gives a ground
reading on one pin and shows a capacitor on the other that charges to the
same amount of resistance.

I was wondering if this might be a back-up plug for the power
Click to expand...

You mean like a factory test point of some sort ? Is it
accessible externally ? Normally, the only externally
accessible power connection, would be the barrel connector.

Paul
 
I found a 2 pin plug socket (don't know if it's called a "sata" plug), on
the side
of the power plug board that gives the same readings on the ohm meter as the
power plug (when the pluig is in - turning on the switch). It gives a ground
reading on one pin and shows a capacitor on the other that charges to the
same amount of resistance.

I was wondering if this might be a back-up plug for the power
Click to expand...


This is presumably intended to supply power to something internal,
which might not be fitted. Charging to the same R means both are
connected to a capacitor, but that doesnt mean its the same power
rail. Grounds will be connected, but the +s might or might not be. An
ohmmeter from internal conector + to external conn + could tell you -
though this wont pick up on any passive filters that may be in the
way. (Obviously you need to discharge both ccts before conecting the
meter.)


NT
 
Paul said:
You mean like a factory test point of some sort ? Is it
accessible externally ? Normally, the only externally
accessible power connection, would be the barrel connector.

Paul
Click to expand...

It's not accessible externally.
 
We recently got an IBM 9511-AG4  lcd monitor. The power jack on the monitor
wasn't making good contact and finally stopped functioning. After lookingat
the board that the jack is install on, I found 4 pins that seemed to be for
the jack. 3 of the pins were grounding and the 4th wasn't. I was thinkingof
connecting the + wire from the ac adapter to the 4th pin and the - wire to a
ground.

Would this be safe?

Thanks.
Click to expand...

I hard wired the power cord and it functions somewhat. There has to be
a plug in the old socket to keep the switch on. Also, it seems the
capacitors need to be charged up (which I do with the ohm meter
attached to the cord that's hard wired) on the + side before it will
turn on if the power's been off for more than a minute or two as well
as the computer off. But I've been able to use it so far.
 
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