# Dell M1730 AC adapter unknown device installed, need help



## kenred2 (Sep 3, 2015)

I ran into this issue several weeks ago and when through every step in Google and found no real solution. When plugged in, it will not charge my battery and my battery was brand new recently purchased from ebay (because my old battery is dead).  I went to the bios only to have found out that the adapter was not recognized and stated unknown. I tried many ways to fix up the problem, such as:
- Turning it off, take out the adapter and battery and pressing and hold the power button for 30secs to discharge, put everything back, doesn't work.
- I went to device manager, uninstall the ACPI battery and rescan hardware changes and still the battery will not charge.

I replaced the adapters twice, I change the battery one.  The battery is aftermarket 3rd party, but as you can see from the photos, it has a charge however the adapter is not charging the new battery at all.  At this point, I have no idea how to fix this problem, if anyone has this system that can share with me a solution to this, please let me know.  

*I don't want to replace the motherboard, that's the last option.  If you have a adapter that works and charges successfully on your m1730, let me know what adapter by posting the information in this thread and I'll see if I can get the same one and try it for this laptop.


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## dorsetknob (Sep 3, 2015)

what is the power rating on your power brick
you need one that outputs at least 7A at 19.5V


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## kenred2 (Sep 3, 2015)

It's a genuine Dell adapter, it reads:
Output: 19.5V

This adapter is REV: A00


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## unclewebb (Sep 3, 2015)

What adapters have you tried?  Looks like the original one was a PA-19 which is rated at 230 Watts and 11.8 Amps and 19.5 volts.  Dell laptops are finicky about power adapters.  If it is not the correct model, the CPU will either slow down to a crawl or it won't charge your battery.  If your adapter is good then it might be your new made in China battery.  Many of these are garbage.  On EBay it can be very difficult to find a decent OEM battery.  Even ones that look like a Dell battery can be full of junk cells.


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## McSteel (Sep 3, 2015)

The pin in the middle of the barrel connector on the charger doesn't seem to be making proper contact with the hole on the laptop's connector. That pin is used for communication between the charger and the laptop, and when there's no connection the laptop concludes you're using a 3rd party (foreign) charger. There should be an option in the BIOS which allows for skipping the charger compatibility check and would allow your battery to charge once you confirm by pressing a button at startup (not sure which one, I think it was F6 or something...)

Alternatively, it could be that the control/communication IC in the charger is fried or that there's a glitch in the laptop's embedded controller... The former would sadly require a replacement charger, and the latter _could_ perhaps be solved by flashing the EC firmware and/or resetting it to factory defaults.

For now, try to wiggle the connector gently to see whether the charger will be recognized. You could also go through all the advanced settings in the BIOS and find the one that allows the system to ignore the charger type. The exact wording escapes me at the moment, but you'll recognize the option when you see it.

As a last resort you could try flashing the latest BIOS and EC firmware, but I don't think the system will even let you do that without the proper charger connected...


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## kenred2 (Sep 3, 2015)

unclewebb said:


> What adapters have you tried?  Looks like the original one was a PA-19 which is rated at 230 Watts and 11.8 Amps and 19.5 volts.  Dell laptops are finicky about power adapters.  If it is not the correct model, the CPU will either slow down to a crawl or it won't charge your battery.  If your adapter is good then it might be your new made in China battery.  Many of these are garbage.  On EBay it can be very difficult to find a decent OEM battery.  Even ones that look like a Dell battery can be full of junk cells.



I don't believe my new made China battery would be the problem, it came to me precharged, which in the pictures show has above 50% remaining.  It's something to do with the adapter or the motherboard of the DC jack (which I am not hoping).  In the desktop, it is showing that the battery has power, but when "plugging" into the adapter, it's not charging the china battery.  The battery reads successfully through the BIOS, but on the adapter side, it stated "unknown device"... I disconnected the adapter and reapply it, it reads "unknown device."  From there, that should give you a clue


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## dorsetknob (Sep 3, 2015)

right  power brick for laptop as  @unclewebb said 
so your problem is probably non standard  non OEM battery which the laptop will not reconise and therefore will not charge

Your going to have to bite the cost bullet and get a new battery
Oem or one that is guarentee that is recognised by the laptop or your money back


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## McSteel (Sep 3, 2015)

Does the laptop start with the charger connected, but no battery? What does it say about the charger in that case?


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## kenred2 (Sep 3, 2015)

McSteel said:


> Does the laptop start with the charger connected, but no battery? What does it say about the charger in that case?



The laptop starts without the battery installed.  On the bios, it would still read as an unknown device


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## McSteel (Sep 3, 2015)

Inserting the battery with the system already running is not the most advisable thing in the world, but _usually_ it won't break anything, and I've seen it "shock" the system into realizing it needs to charge the battery.

But first, how about trying to disable the improper charger warning in the BIOS? You could probably Google several solutions for it, see here and here for example.

I've had a very similar issue with a Latitude E7440 and an aftermarket battery *and* a 3rd party (sworn compatible) charger; inserting the battery while the machine was already running solved the problem. It really must be the embedded controller that's causing your headache.


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## kenred2 (Sep 3, 2015)

I forgot to post this one as well


 


I've disabled the warning previously, and now I went to put it back to default mode.  While it is running on AC adapter, I attempted to put the battery into the laptop just to "shock" it, and same thing, it recognizes the battery, but still refuses to charge..... drives me crazy how I went to ebay back and forth several times to replace the adapter and battery..... I even went as far as doing this:



 


 


 

The one opened is my original Genuine adapter, bought the same one.  Both experience the same problem with unknown device.  The one opened and exposed is where I view where the red wire contacts and it's soldered fine, I didn't have to resolder at all.  So my original adapter has no red wire disconnect to make it an unknown device.... as you can see, I think I've tried about 90% of several methods looking on forums, youtube, google search... nothing


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## Pill Monster (Sep 3, 2015)

Did you check the laptop AC jack?  They sometimes work themselves loose after a few years and require a resolder.....


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## red_stapler (Sep 3, 2015)

What's the condition of the charging pins?  These tended to get bent and will cause your issue:






The internet seems to think the problem is with your DC port though.


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## kenred2 (Sep 3, 2015)

Pill Monster said:


> Did you check the laptop AC jack?  They sometimes work themselves loose after a few years and require a resolder.....



I don't think it has anything to do with the AC jack.  As McSteel suggested, it may have been the "control/communication IC."  But that problem results either if it's the adapter or motherboard in question.  The adapter I recently purchased is used and claiming that it works, so what I am going to do is buy a BRAND new adapter and see if it works, because used adapters may have these "controller" issues.  The Jack however may not be the problem if I can plug it in and start Windows WITHOUT the battery.


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## kenred2 (Sep 3, 2015)

red_stapler said:


> What's the condition of the charging pins?  These tended to get bent and will cause your issue:
> 
> 
> 
> ...



Both of the gold pins are solid, they are not bent or broken, I even used anti-static computer wipes to carefully wipe the inside of the connector... and even with the amount of time cleaning it, it's the same result.


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## kenred2 (Sep 3, 2015)

If worse comes to worse, I'll just get a motherboard off from ebay for the m1730 model.  Let me know which motherboard is the latest and poses best performance.  I couldn't tell the difference:

-Description: Dell XPS M1730 Intel Laptop Motherboard m478, FT342, YU242, 55.4Q601.010
P/N: F513C

-Description: Dell XPS M1730 Intel Laptop Motherboard m478, FT342, YU242, 55.4Q601.001
P/N: Y012C

-Description: Dell XPS M1730 Intel Laptop Motherboard m478, FT342, YU242, 55.4Q601.001
P/N: FT342

Please let me know which of these I should get, it would have been easier if the m1730 has 1 motherboard in particular, but they made multiples that confuses me.  So let me know.  Thanks


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## McSteel (Sep 3, 2015)

It could be that the receptacle for the communication pin is damaged on the motherboard end. Perhaps a bad solder joint, or a cracked one. Maybe it is one of the leads/traces from the connector to the EC... Either way, if you're comfortable with taking a look at it, it might save you some money to try to rescue the board you already have. You need to take out the current motherboard to swap in the new one anyway, so if it were me, I'd inspect the one I have in hand first, then buy another one if there's no other way...

As for the board, all three revisions are compatible, I think they differ by some minor changes in the IC layout on the board as well as using a couple different ASICs for power delivery and perhaps integrated card reader, USB hub, dock interoperability controller etc. Either way, take your MoBo out first, the specific part number should be silkscreened on it, if you're looking to do a 1:1 swap.


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## kenred2 (Sep 3, 2015)

McSteel said:


> It could be that the receptacle for the communication pin is damaged on the motherboard end. Perhaps a bad solder joint, or a cracked one. Maybe it is one of the leads/traces from the connector to the EC... Either way, if you're comfortable with taking a look at it, it might save you some money to try to rescue the board you already have. You need to take out the current motherboard to swap in the new one anyway, so if it were me, I'd inspect the one I have in hand first, then buy another one if there's no other way...
> 
> As for the board, all three revisions are compatible, I think they differ by some minor changes in the IC layout on the board as well as using a couple different ASICs for power delivery and perhaps integrated card reader, USB hub, dock interoperability controller etc. Either way, take your MoBo out first, the specific part number should be silkscreened on it, if you're looking to do a 1:1 swap.



Honestly, having to realize that it maybe the board defective, I was hoping to find a board better than the one I have, if I go for the same 1:1 swap, I may face the same problem again, so I am hoping for a board that doesn't have these problems in the future.  My CPU is an Intell X9000, so I am hoping that 1 of these 3 boards can support the cpu and also hoping that there's a revision board that prevented the problem for later releases/revisions before it got discontinued

Anyways, I'm going to purchase the "new" AC adapter first, if that doesn't work, I would need to get a new board that's compatible, newer than the board I have


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## red_stapler (Sep 3, 2015)

What's your service tag?  I might be able to figure out the original motherboard part number from the build sheet.  Unfortunately I don't work at Dell anymore, so I couldn't research the different motherboard part numbers for you.


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## kenred2 (Sep 4, 2015)

red_stapler said:


> What's your service tag?  I might be able to figure out the original motherboard part number from the build sheet.  Unfortunately I don't work at Dell anymore, so I couldn't research the different motherboard part numbers for you.



PM sent....
Unable to locate the board (didn't want to take the whole thing apart yet)


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