OT: Can a laptop PSU just go bad?

[sjaltenb]

Hey,sorry for the off topic post!

So, I've had my HP laptop for a while now and its always worked great. When the battery dies, nothing happens and it just flashes the 3 little lights, saying there is no charge.

Well i went to plug it in to charge the other day, and it didnt, so i tired a bunch of different outlets in my house, no dice. The charge light at the ps input doesnt turn on either, but the very first time i plugged it in, it kinda flickered a bit then nothing. Im guessing the cap was discharging.

So i multimetered it, 121vAC in, Nothing out. However HP says these are "smart" laptop power supplies, which is something about how it wont charge if it doesnt need to. Does that mean my 0.0 multimeter read could have been innacurate?I broke the thing open and coudlnt see anything wrong, but it was harder than I thought to check. so either way I need a new one. They are pretty messy in there, and i saw a 400V cap i wasnt about to touch.

Does this sound fishy? or does this just happen?

[Scruffie]

Tried changing the fuse? Just a suggestion. My laptop power cable broke on the inside of the rubber, wiggling it about fixed it so then just had to cut it open, solder it up with a new socket and insulate it I don't see why the PSU would suddenly die when you went to charge it but I guess it depends on the protection inside your laptop or if it just gave up.

[Johan]

pull the battery on your laptop and try to run on psu alone...it might be a preblem with the battery and not with the psu...
...smart psu probably means it it doesnt deliver any dc unless it sees a load, so it might not be possible to measure the psu output uniless it is pluggen in...
j

[Papa_lazerous]

the smartness of the charging circuit may well be handling within the laptop itself and I would expect the PSU to have some sort of output.  If this isn't the case then it would be very hard o test indeed. I am guessing it would put out some form of juice out on power-up at the very least so it could sense the load in either case.  so connect you meter up before cycling the power and see if it does anything.  Odds are the PSU has just gone bad

[brett]

Happens and happens and happens.
Wallwarts and laptop PSs have a high failure rate long-term.  Dry electrolytics and internal fraying of cheap wires.
Destop PSs are a little more reliable.  But my desktop is on its third supply.

[Cliff Schecht]

First suspect is always the cord, followed by the electrolytics. Even those snazzy Oscon caps wear out eventually. This wear is of course expedited by hard/long use. If its a problem on the laptop-side of things however, you could be in for a tricky and/or impossible repair. I've had laptop power problems before - fortunately they were covered by warranty!

Also, speaking of PSU's, I just fired up the "TBA" PAiA SMPS prototype today.. Gotta love it when things work right on the first try!

[Sir H C]

Friend's laptop had the power jack in the PC go bad and cause such a problem.  These smart supplies have intelligence in them, my Dell will not let me use the 75 watt supply (for just the laptop) with the docking station saying "Too little power".  That is something that it can figure out from the supply talking to it.