How to test notebook power supply with sense pin?

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!).

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 :-)

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 ." put finger to keyboard and composed:

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

- Franc Zabkar

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!