On Sun, Aug 17, 2025 at 2:10 PM Tomas Kuchta <[email protected]> wrote:
> Dell barrel chargers have 3 pins actually: outer barrel, inner barrel and > center pin. > > HP and other chargers only have outer (just simple) barrel an center pin. > > The third pin on dell charger is id pin. Probe to see the charger id > protocol. > > -Tomas > > > On Sun, Aug 17, 2025, 15:50 Michael Barnes <[email protected]> wrote: > > > On Sun, Aug 17, 2025 at 12:32 PM Denis Heidtmann < > > [email protected]> > > wrote: > > > > > Check the polarity and current rating. > > > -Denis > > > > > > On Sun, Aug 17, 2025 at 12:27 PM Michael Barnes <[email protected] > > > > > wrote: > > > > > > > Here's a confusing one. I have an HP laptop with the usual 45W 19V > > power > > > > supply. I'm doing some work with an associate's Dell laptop, which > also > > > has > > > > the typical line lump 45W 19V supply. I figured I'd just plug my HP > > > supply > > > > into the Dell as the connectors are the same (generic 2.5mm barrel). > > > When I > > > > powered up the Dell, I get a BIOS warning screen that says > questionable > > > > power supply and it would not charge the battery. > > > > > > > > I've checked both supplies with voltmeter and oscilloscope, nothing > is > > > > riding on the DC, both outputs are clean and identical. > > > > > > > > What does Dell do that it knows it is not a Dell supply and will not > > > charge > > > > the battery? I've seen this with USB-C and micro-USB connectors that > > have > > > > ID pins incorporated, but that doesn't account for a straight 2-wire > DC > > > > barrel plug. > > > > > > > > Any one run into anything like this? > > > > > > > > Thanks, > > > > Michael > > > > > > > > > > > All ratings identical, voltage, current, polarity, etc. Found another > > laptop supply, a generic no-name, same issue. All supplies work fine with > > my HP, all but the Dell branded supply give an error trying to power the > > Dell and do not charge the Dell battery. > > > > Michael > > > Well, you learn something new every day. Not that I've previously ever had occasion to pay attention, I've never noticed a 3-pin barrel connector before. I guess that answers the question. Thanks, Michael
