How to test notebook power supply with sense pin?

C

Craig .

Guest
I have a Samsung R580 notebook in very good condition, when I test the
power supply I get very low (0.6V) voltage on the pin and also on the
inner barrel. (The plug has earth on the outer barrel and then a
separate line on the inner barrel and also a central pin, again
separate) I assume the pin is a sense pin that *may* only ramp the V
up when the unit is connected?

When I connect the adapter with the unit dismantled I get no voltage
across any of the pins on the DC IN plug.

Do you suppose this is a faulty power supply or is the fault with the
laptop?

I'm considering just using a separate 19v adapter but am uncertain as
to whether the V+ should be on the centre pin or the inner barrel.
 
Den 16-07-2011 10:08, Craig . skrev:

But how do I know which line is meant to be V+? Will
dismantle the power supply brick (man that's a pain!).
Click to expand...
Put the brick in the freezer for a while then the joint becomes brittle
an the rest is pure fun :)

--
Uffe Bćrentsen
 
On Jul 16, 5:48 pm, "Craig ." <mailc...@gmail.com> wrote:
I have a Samsung R580 notebook in very good condition, when I test the
power supply I get very low (0.6V) voltage on the pin and also on the
inner barrel. (The plug has earth on the outer barrel and then a
separate line on the inner barrel and also a central pin, again
separate)  I assume the pin is a sense pin that *may* only ramp the V
up when the unit is connected?

When I connect the adapter with the unit dismantled I get no voltage
across any of the pins on the DC IN plug.

Do you suppose this is a faulty power supply or is the fault with the
laptop?

I'm considering just using a separate 19v adapter but am uncertain as
to whether the V+ should be on the centre pin or the inner barrel.
Click to expand...
OK perhaps I was imagining it but now when I test there is only 0.05V
sometimes on the inner barrel, the rest is 0. Sounds like a cactus
power supply? But how do I know which line is meant to be V+? Will
dismantle the power supply brick (man that's a pain!).
 
It sounds like the power supply has failed. Diagnosis of these
is difficult, because many faults result in logic shutdown (and that
symptom is too generic). I'd cut the plug and a foot or so of
wire from the adapter and splice the supply to a resistor load, just to
see if it works then.

Bad laptop, bad power socket on laptop, bad plug on power supply,
and bad power supply are the four main branches here.
 
On Sat, 16 Jul 2011 00:48:26 -0700 (PDT), "Craig ."
<mailcrai@gmail.com> put finger to keyboard and composed:

I have a Samsung R580 notebook in very good condition, when I test the
power supply I get very low (0.6V) voltage on the pin and also on the
inner barrel.
Click to expand...
It may help to examine the circuit diagrams of other Samsung
notebooks:
http://www.4shared.com/dir/0S3W-zjF/MOBO_SCHEMATICS.html#dir=89663252

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.
 
On Jul 17, 7:30 am, Franc Zabkar <fzab...@iinternode.on.net> wrote:
On Sat, 16 Jul 2011 00:48:26 -0700 (PDT), "Craig ."
mailc...@gmail.com> put finger to keyboard and composed:

I have a Samsung R580 notebook in very good condition, when I test the
power supply I get very low (0.6V) voltage on the pin and also on the
inner barrel.

It may help to examine the circuit diagrams of other Samsung
notebooks:http://www.4shared.com/dir/0S3W-zjF/MOBO_SCHEMATICS.html#dir=89663252

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.
Click to expand...

Well I dismantled it and it was FILLED with some kind of (flame
retardant?) white gap filler like substance.. I mean it was chock a
block. I assume something has overheated or the goop has physically
brocken something.. I removed the goop as best I could and tried
bridging what looked like a shot fuse but it just popped.. Cut off the
cable and attached it to another 19v psu. lappie goes fine.
thanks!
 
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