Dell Latitude 7390 Touch charger question?

Jon_01

I have an i5 model of the 7390 (13 inch) which I bought from Dell refurbs in April, it's only used for Word so it's fine.

It comes with a power Brick that far too big to carry in a 13 inch case.

It's supposed to be able to be charged through the usb c port, which something that will fit in the case, but that's where I have a problem.

I've tried a Tecknet 65w charger.  But all I get is 'use the recommended charger' error. And, yes, it's a cheap and nasty charger, so I guess no real surprise.

I've tried a Ugreen 65w, that charges it but give the error, that it's 'slow charging' in W10. When the unit is rebooted, it gives the bios message that a 'low wattage charger' is connected?

The supplied brick charger is 65w, so why would it think a usb c 65w is a slow charger? Would it help, do you think, to try it with a 100w charger.

Anyone suggest what to try next?

Thanks...

Neil_Jones

Dell laptops only charge if they know its a genuine charger.  This isn't a new thing, its been the case for literally the last 15 year or so.

You may have to find a specific charger that has a "signal" (for want of a better description) for your unit that will charge it.  This is nothing to do with the wattage or the amperage of the charger, there's something else the unit is looking for that isn't present in the chargers you have, but is present in the original charger, and it'll almost certainly be something invisible.

And that's what your problem is.  So either find a charger that has the required "signal", or take the original charger with you.

Jon_01

Neil_Jones said:

Dell laptops only charge if they know its a genuine charger.  This isn't a new thing, its been the case for literally the last 15 year or so.

You may have to find a specific charger that has a "signal" (for want of a better description) for your unit that will charge it.  This is nothing to do with the wattage or the amperage of the charger, there's something else the unit is looking for that isn't present in the chargers you have, but is present in the original charger, and it'll almost certainly be something invisible.

And that's what your problem is.  So either find a charger that has the required "signal", or take the original charger with you.

Thanks, Neil.

I understand your point on the original charger, but that's a standard 7.4mm barrel type. I know about the issues with those.

But I've spoken with Dell support ten minutes ago, they say that any usb c charger 'should' work!  

They've searched their system and can't find any info as to what charger it's looking for.  They say Dell doesn't make a usb c charger and have no idea what the 'recommended charger' it's asking for is!  So that's not helpful at all.

PHK

Just to check that the charger supports USB-PD (power delivery) or it won't be able to communicate with the laptop and so a lower power compatible mode.

Jon_01

PHK said:

Just to check that the charger supports USB-PD (power delivery) or it won't be able to communicate with the laptop and so a lower power compatible mode.

Thanks, but the Tecknet charger does have PD and that doesn't work at all!!!

https://www.amazon.co.uk/gp/product/B002UJ0STW/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

The Ugreen doesn't have have PD and that slow charges. Or, is their 'fast charge' what they call PD?

https://www.amazon.co.uk/gp/product/B08CDDSVN4/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1

wongataa

Jon_01 said:

It's supposed to be able to be charged through the usb c port

Are you sure about that?

Jon_01

wongataa said:

Jon_01 said:

It's supposed to be able to be charged through the usb c port

Are you sure about that?

Dell support confirm it should. And I've found one charger that will slow charge it.

wongataa

Jon_01 said:

wongataa said:

Jon_01 said:

It's supposed to be able to be charged through the usb c port

Are you sure about that?

Dell support confirm it should. And I've found one charger that will slow charge it.

You will need a suitable USB cable as well as a suitable charger.  The wires need to be thick enough to carry the necessary power.  If you have a suitable cable and your chargers still don't charge it properly then I would suspect the chargers aren't suitable.

cerebus

What's wrong with this charger ? It's pretty slim 

https://www.amazon.co.uk/Dell-Latitude-Rugged-Adapter-Charger/dp/B07SZNPLZ1/ref=asc_df_B07SZNPLZ1/?tag=googshopuk-21&linkCode=df0&hvadid=372163298573&hvpos=&hvnetw=g&hvrand=13899589365005995209&hvpone=&hvptwo=&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=9045509&hvtargid=pla-797495236213&psc=1&tag=&ref=&adgrpid=75990993029&hvpone=&hvptwo=&hvadid=372163298573&hvpos=&hvnetw=g&hvrand=13899589365005995209&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=9045509&hvtargid=pla-797495236213

What voltage out put does that ugreen charger have ? Does it go to 19.5v?

Jon_01

cerebus said:

What's wrong with this charger ? It's pretty slim 

https://www.amazon.co.uk/Dell-Latitude-Rugged-Adapter-Charger/dp/B07SZNPLZ1/ref=asc_df_B07SZNPLZ1/?tag=googshopuk-21&linkCode=df0&hvadid=372163298573&hvpos=&hvnetw=g&hvrand=13899589365005995209&hvpone=&hvptwo=&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=9045509&hvtargid=pla-797495236213&psc=1&tag=&ref=&adgrpid=75990993029&hvpone=&hvptwo=&hvadid=372163298573&hvpos=&hvnetw=g&hvrand=13899589365005995209&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=9045509&hvtargid=pla-797495236213

What voltage out put does that ugreen charger have ? Does it go to 19.5v?

Nothing wrong with the supplied charger. But the laptop is 13 inch and all the 13 inch cases don't have enough room for it.  Whereas a usb c charger has the mains plug and the charger integrated, so take up much less space and will fit into the case.

The Ugreen charger outputs up to 20v.

Jon_01

wongataa said:

Jon_01 said:

wongataa said:

Jon_01 said:

It's supposed to be able to be charged through the usb c port

Are you sure about that?

Dell support confirm it should. And I've found one charger that will slow charge it.

You will need a suitable USB cable as well as a suitable charger.  The wires need to be thick enough to carry the necessary power.  If you have a suitable cable and your chargers still don't charge it properly then I would suspect the chargers aren't suitable.

Yes, I thought about that yesterday.  I'm fairly sure the lead I'm using is rated 65w, but I'm not 100% certain so I've ordered a couple of different 100w leads to test.