Look at you fix this thing like a boss👌

@JonnyFix

3 ай бұрын

Thanks! Should be doing it for a living..... and being my own boss!

802.3at PoE is nominally 48v so there would be no issue running a PoE device without the control protocol - some PoE injectors are passive and there are thousands of them deployed in the field, due to a few differing standards that came in that weren't interoperable ( older Cisco wireless APs for example). Also a non-PoE device won't (or at least shouldn't) be affected by having 48v run though - this voltage is DC-filtered on ingress and the card should only ever see the data signal. The one issue with running passive PoE is that it, and earlier 802.3af wasn't compatible with gigabit ethernet, which uses all four pairs. You'll note that your phone only connected at 100Mbps when the port was dodgy. 24v is non-standard, and I think only used for some older access points from Ubiquiti (and some other vendors like Mikrotik). I don't think even Ubiquiti use it on their newer stuff though - it was always a bit janky and we network engineers tended to look down our noses at the 'toy' stuff that ran passive like that 😂 Nice fix that!

@JonnyFix

3 ай бұрын

Cheers for the info. You sound like you're in the right industry! It's good to have a decent budget behind you so you can avoid using the passive junk :) I accidentally sent POE to my PC some time ago...... I think it smoked the magnetics on those 2 pairs and no longer does gigabit.... and I did see a puff of smoke emanate HAHA. If the device isn't POE capable I guess there's no requirement to design to deal with it on the assumption it should never happen. Maybe I should do a video on my PC and investigate what actually happened!

@jasejj

3 ай бұрын

@@JonnyFix Interesting. To be fair I've not tested the theory with actual hardware, and I guess some stuff won't have the filtering. You really don't want to be finding out that it's wrong on your brand new, $2000 laptop lol. Yeah I enjoy networking, I was a field engineer for many years deploying microwave connections, dark fibre and the like as well as on-prem kit. Don't get as much chance to get my hands dirty any more though as I work for a largish UK ISP designing stuff in the datacentres, but I like to get out and do real engineering every so often 😉

Well done you clever devil lol :-D I know nothing about that box of madness lol. Odd how there wasn't protection on the mosfets. Oh ok cheapness lol. Hmm windows xp, i used that os for years, my local tesco supermarket ran the self service machines using xp. One day i walked into tesco and one of the machines had crashed, it was obvious it was xp. i never knew. have you fallen asleep reading my jibbering lol.

@JonnyFix

3 ай бұрын

Hahah... old laptops still good for something including filling in for my lazyness when the cable to the main workhorse doesn't reach far enough. I still don't get what part the fuses play in all of it, would love to get a schematic.

60v rated on a 55v rail.... hmm thats a bit close, might be why they died.

@JonnyFix

3 ай бұрын

Good point. I think POE max is usually 48V, maybe the PSU drops if all of the ports are supplying. Maybe regulation is off and is actually another fault I need to look at. I haven't yet worked out how they're dividing the main rail to get 24V either, I think there's another buck converter in there. Previously the main 400V filter cap failed and unusually the secondary caps are still fine.