Dell charger problem - underclocked CPU

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kezs

Weaksauce
Joined
Nov 12, 2006
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Hi all,

I'll start with some context: I'm one of the many Dell customers disgruntled by the annoying charger problem. I've had a Dell XPS l502x for a couple of years and a few weeks ago I started getting the message below:

"Your system will operate slower and the battery will not charge. Please connect a Dell 130W AC adapter or higher for best system operation."

So basically with Dell laptops you get that after a while, and you're never sure whether it's the charger, the AC socket or the motherboard - and I don't know anyone else who has this charger to test it.

But that's not even my main problem. I'm fine (sort of) with only being able to use my computer plugged in. The real problem is that this issue underclocks my computer to 0.75ghz (down from 2.5ghz), which is incredibly annoying. It makes no sense at all. If I unplug the charger and let it run with what little juice my battery still has, the CPU clock goes back up, but it's always limited to 0.75ghz when it's plugged in. I can't believe how annoying that is.

So my real question is... is there a way around that? Like an overclock tool that'll let me "overclock" it back to its standard 2.5ghz? From what I've read the i5s are really hard to overclock, but I haven't seen anyone else trying to just "normalclock" it. I've tried uninstalling the Microsoft AC Adapter from Device Manager. Also tried disabling Intel SpeedStep Technology and Charger Behavior in BIOS with no luck.

Any help will be greatly appreciated.
 
Elaborate complaint if it's just a bad charger. ;) I used to buy Dell laptops for a long stretch and never had a problem with charger warnings, if the right charger was plugged in.

I imagine you've already turned off power management, because you can't stand the thought of a laptop running at less than 100% frequency. What is this I don't even

If you have disabled power management forever, and charged the battery a lot while on, I can totally see how that may have killed that portion of the motherboard if it turns out not to be the charger.
 
pxc said:
Elaborate complaint if it's just a bad charger. ;) I used to buy Dell laptops for a long stretch and never had a problem with charger warnings, if the right charger was plugged in.

I imagine you've already turned off power management, because you can't stand the thought of a laptop running at less than 100% frequency. What is this I don't even

If you have disabled power management forever, and charged the battery a lot while on, I can totally see how that may have killed that portion of the motherboard if it turns out not to be the charger.
Click to expand...

There's a big difference between running at 100% all the time and never letting it go beyond 30% (even though there's plenty of power available).

I tested it with my mom's laptop charger, which is 65w: apparently my laptop does recognize it's a Dell 65w charger, while my mom's laptop gives the same error when I connect my charger to it. So I guess it's safe to say it's a charger problem rather than a motherboard one and I've ordered a new one already.

But my complaint remains. Dell is the only laptop maker I know that has this fragile wire that often breaks and renders the charger and the computer useless unless you get a new one, even though the charger still works fine. There should at least be a way to disable that check for advanced users deep inside the BIOS somewhere. It's happened to my wife and to my coworker as well, so it's not a rare problem at all, and it's been happening for years, judging from complaints you find online. They should either make a more resistant charger (mine hasn't gotten any kind of beating at all), or give the option to override it, or at the very least allow the processor to run at full speed.
 
kezs said:
There's a big difference between running at 100% all the time and never letting it go beyond 30% (even though there's plenty of power available).

I tested it with my mom's laptop charger, which is 65w: apparently my laptop does recognize it's a Dell 65w charger, while my mom's laptop gives the same error when I connect my charger to it. So I guess it's safe to say it's a charger problem rather than a motherboard one and I've ordered a new one already.

But my complaint remains. Dell is the only laptop maker I know that has this fragile wire that often breaks and renders the charger and the computer useless unless you get a new one, even though the charger still works fine. There should at least be a way to disable that check for advanced users deep inside the BIOS somewhere. It's happened to my wife and to my coworker as well, so it's not a rare problem at all, and it's been happening for years, judging from complaints you find online. They should either make a more resistant charger (mine hasn't gotten any kind of beating at all), or give the option to override it, or at the very least allow the processor to run at full speed.
Click to expand...

I am not exactly sure how the Dell laptops sense what charger is plugged in. I am guessing it has to do with a resistance measurement of some kind, or possibly even a frequency test.

Unless the center lead(wire) is missing, I am pretty certain that it is not broken.

There is probably something wrong internally with the power supply.

IF the laptop did not have this detection capability, it could lead to an electrical fire and or fried hardware.

In addition to that, trying to run a laptop at full speed and charge the battery with an inadequate charger would most likely lead to hard shutdowns and restarts.
 
cyclone3d said:
I am not exactly sure how the Dell laptops sense what charger is plugged in. I am guessing it has to do with a resistance measurement of some kind, or possibly even a frequency test.

Unless the center lead(wire) is missing, I am pretty certain that it is not broken.

There is probably something wrong internally with the power supply.

IF the laptop did not have this detection capability, it could lead to an electrical fire and or fried hardware.

In addition to that, trying to run a laptop at full speed and charge the battery with an inadequate charger would most likely lead to hard shutdowns and restarts.
Click to expand...

I won't argue with you on the technical details... but I've had laptops from Toshiba (2), Sony, Acer, Asus, LG and now Dell. The only one that has this sort of control is Dell's and the only one that's given me a headache is Dell's. Same thing with my wife's laptops. Seems to me like it's either too sensitive or just plain wrong.

I guess what frustrated me the most was the amount of time and effort I had to spend until I figured the whole thing out. They're like: "buy another charger; if that doesn't work, replace the AC socket on the laptop, and if that doesn't work, replace your motherboard". If my mother didn't own a Dell laptop I'd be left spending money to guess what the problem might be.

Anyway, I'm just venting my frustration :) Thanks for the input everyone.
 
Dell chargers (as well as HP/Compaq's) use a resister across the positive terminal and the center pin to drop the voltage seen by the computer on the center pin. The voltage seen tells the computer which charger is plugged in. If that wire or socket pin breaks, the charger can no longer be detected. It can also happen if the resistor burns out.

Seeing that the computer can detect a 65w charger, I'm going to bet that the charger itself is the culprit. Try taking the battery out and plugging it in to see if it restores the CPU speed in the mean time. I believe there's a setting in the Quickset utility to disable the monitoring of the AC adapter, but I don't have my XPS 17 anymore to check. You should also be able to disable adapter warnings in the BIOS settings, but I'm not sure that would restore the CPU speed.
 
kezs said:
But my complaint remains. Dell is the only laptop maker I know that has this fragile wire that often breaks and renders the charger and the computer useless unless you get a new one, even though the charger still works fine.
Click to expand...
I agree 100% with that complaint. It's a very poor design.

Glad to hear you narrowed down the problem.
 
They can also use a little ID chip which can burn out too,

I had to be extremely careful of that "feature" when modifying dell chargers for use with other brands.
 
Meaker said:
They can also use a little ID chip which can burn out too,

I had to be extremely careful of that "feature" when modifying dell chargers for use with other brands.
Click to expand...

All the Dell and HP chargers I've see were just resistor ID'd Cut the end off, solder the two actual charging wires onto the new connector and snip back the third wire.


I've used Dell and HP charger interchangeably in a pinch Of course the BIOS would complain, but they did the job I needed them to do.

The only ones I've seen that did have an ID chip were Apple's Magsafe chargers. With those the chip is in the connector itself and really has nothing to do with the charger itself other than telling the system what kind of charger is connected so it can enable charging.
 
Dell uses a 3-pin ID chip in the charger to determine wattage (having taken several of them apart). That could have burned out.
 
ryan_975 said:
I've used Dell and HP charger interchangeably in a pinch Of course the BIOS would complain, but they did the job I needed them to do.
Click to expand...
I have too and didn't think much about it supposedly "not working". :p
 
Dell does use a chip, i've seen it lol.

While the chip is annoying they do have the best 240W bricks on the market.
 
Meaker said:
Dell does use a chip, i've seen it lol.

While the chip is annoying they do have the best 240W bricks on the market.
Click to expand...

Wow, I suppose they do. The few Dell chargers I've actually taken apart were generic "Replacement Charger" types, I figured they'd at least get it close to how an actual Dell charger was built. I wonder why they worked at all if they didn't have the ID chip, or maybe I just couldn't find it. Sorry to have given incorrect information.
 
I just got my replacement charger (one of the cheaper ones you find at amazon). It works and is recognized as a 90w Dell charger.

The battery had been completely drained while using the last charger. Windows showed it at 0% for quite a few days. Right after I got the charger I connected it and the battery started charging... but as soon as it was full, the LED indicator started blinking 3 times orange and then a long blue. According to this it means "temporary battery failure". I took it out and it's pretty hot... but the pattern clearly wasn't "unsupported charger". So which would be more likely? Is my battery gone because it went over a month without charging (and maybe a couple of weeks with no charge)? Or is there any chance this is the charger's fault? Should I return it?

On a side note, is it worth it to try and open my old charger's brick and see if I can find the problem, just for the hell of it, or shouldn't I even bother?

Thanks again everyone.
 
It probably just overheated (they have temperature sensors in them). Let it cool down and put it back in and see if it does it again. If it does, then the battery is probably toast. Li-Ion batteries are particularly sensitive to be left in a discharged state. So it's possible that it may have been damaged.
 
Turns out you were right, ryan. Apparently the battery just got sort of uncalibrated. The first time I charged it after getting the new charger it overheated; then I was using it and it went from 45% to 7%. I charged it again and now it's got its calibration back and there are no more issues. Good. :)

Again, thanks everyone for the input.
 
Yeah they don't like being at 0%, glad it recovered.
 
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