How to test notebook power supply with sense pin?

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.

Reply to
Craig .
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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!).

Reply to
Craig .

Den 16-07-2011 10:08, Craig . skrev:

Put the brick in the freezer for a while then the joint becomes brittle an the rest is pure fun :-)

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Uffe Bærentsen
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=?ISO-8859-1?Q?Uffe_B=E6rentse

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.

Reply to
whit3rd

On Sat, 16 Jul 2011 00:48:26 -0700 (PDT), "Craig ." put finger to keyboard and composed:

It may help to examine the circuit diagrams of other Samsung notebooks:

formatting link

- Franc Zabkar

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Reply to
Franc Zabkar

89663252

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!

Reply to
Craig .

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