I have a 3-pin Dell PSU spec’d as 19.5v 3.34A and DMM measures at 20v unloaded. The power reqs on the HP laptop are 19.5v 3.33A. AFAICT, that’s a match. Even the 3-pin barrel connector geometry matches. So what’s the problem?
The center pin is a “smart pin” aka “data pin”, as I came to learn. According to @over_clox@lemmy.world, this PIN basically passes brand info so HP can reject non-HP PSUs. But according to this article, the data pin is used to “regulate” the voltage -- which I take to mean it negotiates the voltage for transmission as USB-PD does. If it’s merely negotiating power reqs, then the Dell should work.
It’s possible both sources are correct.. perhaps HP has its own proprietary way of negotiating voltage and Dell has theirs.
Someone even claims that the data channel is used to communicate temp info so a PSU does not overheat. If that’s true, then perhaps it was a good design (noting that the USB-PD standard did not emerge yet).
But is it true about the communication? Considering there are hacks with a resistor or something to satisfy the data channel, it’s hard to believe that the communication is that sophisticated.
This page advises HP owners to always buy HP-branded PSUs. But it’s unclear if that’s just overly safe nonsense.
I just responded to the other post, and I definitely agree with you that when you're working with so many systems, knowing you have a baseline for the power supplies is important! (Especially given how sketchy those third-party adapters can be...)
But I will say I think it's pretty anti -consumer, and not accidental at all, that there is vendor lock in there. And as I said in that reply, I think a setting in the BIOS with a warning (and maybe a warranty invalidation?) that allowed it would have been the more friendly approach, but I can only imagine how much the lawyers would yell about why that's a bad idea, haha
USB-PD made me so happy, I was using my Apple power adapter with my Surface and Dell laptops and it was great!
Well put.
Though I've had little trouble using other power supplies across brands, so I wonder if this is a single HP line.
I've never run across this in business models - if the barrel fits it works, but each brand used their own barrel design, whether that was a different size or a pin in the middle.
And I've worked with many brands since the mid 90's - I've deployed thousands of machines over the years - not to say I've seen all of them, but a lot of the major brand's business models.
Consumer models are just garbage, so if this happens there I'm neither surprised nor concerned. I never buy consumer models - they're garbage, and cheaper for that reason.
And now C is resolving the issue.