# [SOLVED] Signal pin on power supply of Dell 9400



## Leo G (Mar 8, 2011)

I have an older Dell Inspiron 9400 laptop. When I plug the power supply in there is a signal pin that tells the computer that it's a real Dell power supply. 

If it doesn't see this signal it cuts the CPU speed to 1Ghz, the CPU is a 1.8Ghz.

I suspect this is to keep the battery power lower while on battery by keeping the CPU at half speed. This feature stinks.

If I wanted a 1Ghz computer I would have bought one.

So, is there any way to over ride this? I'm having a problem with the signal not getting through. I have multiple power supplies and sometimes I can get one to work and then a few days later it won't connect the signal to tell the computer to use full speed. I've played games with it, bend the pin, use a different power supply, blow the contacts out with air. And sometimes it works and other times it doesn't.

So...any way to over ride this "feature"?

Thanks


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## Done_Fishin (Oct 10, 2006)

*Re: Signal pin on power supply of Dell 9400*

I have come across power connectors that signal the laptop that the power jack is connected by use of a centre pin which is shorted through to one of the other power connections. On these connectors there are 2 connections apart from the centre pin and are the inside and outside circular rings of the power connector separated by a ring of plastic. I would suspect that you would have to modify the receptacle it fits so as to mimic the power plug connection. However that may also disable the battery by switching the circuit into charge mode, thus not allowing it to power on. 

Check the power jack on the charger to see where the centre pin connects and mimic the connection. If you leave the charger unplugged but connected to the laptop what does it do ?? Does it allow you to power on and if so does it still throttle back the CPU speed ?


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## Leo G (Mar 8, 2011)

*Re: Signal pin on power supply of Dell 9400*

I know I can pull the plug on the charger and the computer stays on. I don't know (yet) if I can power up with the charger plugged into the computer but not powered up. I'm 99% confident that it will start up.

With the power supply plugged into the computer but not plugged into the wall the computer will go to 1.8Ghz.

Unplugging the jack from the rear of the computer produces no change and it max's out at 1.8Ghz.

Also you can tell if the signal from the power supply is connecting because the change over of the battery icon to the charger icon is very fast. If the signal connection is not there the switch over of icons takes about 4 seconds.

I have a charger that has a broke signal pin, from me screwing around a little to much. The battery will charge, but it won't go above 1Ghz.

I just think this is a way to force you to have a Dell power supply. Pretty lame of Dell to do this.


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## spunk.funk (May 13, 2010)

*Re: Signal pin on power supply of Dell 9400*

There are many available Generic power adapters on Ebay that are "Dell Certified" (eg) they fool the Bios into believing it is a Dell Power Adapter. And they are around $12 American. Once the power adapter is plugged in boot into the Bios and go to the *Battery *section it will tell you that it recognizes the battery as a Dell, or not. 
For the adapters you have, If you just charge the computer battery, you should be able to boot it up with the power adapter removed and it should run at full GHz.


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## Leo G (Mar 8, 2011)

*Re: Signal pin on power supply of Dell 9400*

I'm using one of those cheap power supplies and usually it works fine. Sometimes it just won't kick in. It has a Dell battery, the power supply, not so much.


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## spunk.funk (May 13, 2010)

*Re: Signal pin on power supply of Dell 9400*

It doesn't matter what power supply you use, boot into Setup (Bios) go to the *Battery *section, if it doesn't recognize your Power Supply as a Dell, it will say so. That way you will know. You can get a cheap generic one that fools the Bios into believing it's a Dell on Ebay.


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## Leo G (Mar 8, 2011)

*Re: Signal pin on power supply of Dell 9400*

Would anyone be able to help me do this?


Bypassing the DELL unrecognized adapter issue



> Bypassing the DELL unrecognized adapter issue
> 
> Dell is notoriously infamous for selling adapters that tend to go bad after few years of heavy usage. In the last 3 years of my laptop use, I’ve already had to change my adapter thrice due to an unrecognized adapter bios warning. You can read about why this issue occurs here .
> 
> ...


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## spunk.funk (May 13, 2010)

*Re: Signal pin on power supply of Dell 9400*

Look, you can edit files in the CMOS/BIOS or Registry and possibly brick your computer, or you can just buy a "Dell" power adapter for as little as $9.00 Dell 9400 power adapter | eBay


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## Leo G (Mar 8, 2011)

*Re: Signal pin on power supply of Dell 9400*

Figured out this was a program. I tried it and it wouldn't allow me to access clocking.

I did a bunch of reading and a few sorta solutions were mentioned. All of them were "they might work"

One of them was to leave the power adapter plugged into the computer but disconnected from AC power. Power down the computer and remove the battery.

Press the power button for 20 seconds.

Put the battery back it and power up the power adapter.

At this point the little power lead flashed which told me that it was charging the battery. A good sign.

I powered up the computer and it went through the boot cycle and it showed the charging symbol in the tray. It also would go up to the 1.8Ghz max like it was suppose to.

So I don't know how permanent or temporary this fix is. But for now it seems to be working normally.


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## spunk.funk (May 13, 2010)

*Re: Signal pin on power supply of Dell 9400*

Good job! Looks good. If you continue to have problems, try a new power adapter from Ebay.


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## Leo G (Mar 8, 2011)

*Re: Signal pin on power supply of Dell 9400*

This is my 3rd power adapter. It's from Amazon, same diff.

They work for a while and then stop. I'd rather not keep buying them when I already have several that should work.

Starting to be time for a new computer anyway. Always tough to plunk down the bucks when you have a computer that works. I'm not one for upgrading for the sake of the upgrade.


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## spunk.funk (May 13, 2010)

*Re: Signal pin on power supply of Dell 9400*

Most sellers on Amazon have up to 90 day warranty periods. If the power adapter is a true Dell power adapter, and you have had it for less then a year, you can return it to Dell for a free replacement


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## Leo G (Mar 8, 2011)

*Re: Signal pin on power supply of Dell 9400*

The power adapters make it past the 90 day period. I only have one OEM power adapter and it still works after I did surgery on the DC plug. The center pin wire broke internally and I soldered it back together. But the cord is chewed up from getting caught in my recliner mechanism more then once. I'd like to replace it but at $100 it seems a little steep.

The fix I used only worked the once. It does work if I want to pull the battery and hold the button and go through the full boot each and every time I want to start up my computer, which I don't. I just want it to boot through the hibernate function and still be able to get the full speed from the computer.

I think this is a horrible tactic that Dell does. Limiting the computers speed just because of using a different power pack. :nonono:


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## spunk.funk (May 13, 2010)

*Re: Signal pin on power supply of Dell 9400*

You can get a Dell Power adapter for your model from Amazon for as little as *$5.00* and a max of *$32.* http://www.amazon.com/s/ref=nb_sb_n...ld-keywords=dell+inspiiron+9400+power+adapter they have worked for me, they should work for you. If you get one that doesn't work, send it back and get a refund.


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## Leo G (Mar 8, 2011)

*Re: Signal pin on power supply of Dell 9400*

I'm tired of the generic power adapters. Even if I can swap them out if they fail under warranty it's a pain. I went and looked at Dell.com today and the power adapter was $70, and then had a $7 off sale. I also found a 10% coupon and applied it. I got out of there for $60 including tax and shipping.

The original power adapter still works. It's just that the plug end is a mess because I needed to do surgery on it and solder everything in place. But it still works. The open wires on it make me worried it might short out and I have played the game to protect it. But I don't want to use it as my main power supply. So for now I bit the bullet and got the OEM. If it lasts as long as the original it'll be worth it. I've already bought 3 generics for about the same price and all 3 will power but won't charge the computer.

Thanks.


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## spunk.funk (May 13, 2010)

*Re: Signal pin on power supply of Dell 9400*

If you take a look at the links in post *#8 *and *#14*, the power adapters all have the Dell logo on them, most of them are priced under $20 they are not generics. but do what you like.


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## Leo G (Mar 8, 2011)

*Re: Signal pin on power supply of Dell 9400*



spunk.funk said:


> If you take a look at the links in post *#8 *and *#14*, the power adapters all have the Dell logo on them, most of them are priced under $20 they are not generics. but do what you like.


If you read the reviews on most of them that claim they are OEM Dell you'll find that the buyers discover they are clones.

My #8 and $14 must be different from yours.


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## Leo G (Mar 8, 2011)

*Re: Signal pin on power supply of Dell 9400*

Hopefully this is the end of this. I got the new power adapter and it works. It's the new style, smaller sleeker. I don't like that they eliminated the strap that would hold the power cord after you wrapped it around the adapter. They have a little clip that allows you to wrap the 19.5v output cord around the adapter and it clips to the last loop of the cord. But it gives no option for the AC cord. I suppose you are suppose to remove it every time you put it in your laptop case....come on Dell.

But it works, I get full speed while on AC power, the battery charges.


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## Done_Fishin (Oct 10, 2006)

Sounds good .. glad you got that problem fixed !!
Now for the rest of them :smile:


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## Leo G (Mar 8, 2011)

Ya, thee ole laptop is getting on in age. I've had this baby for quite some time now. But I like the screen size, it's not a 1080 shaped screen. I don't like the long narrow computer screen as much as I like the taller screen.

Wish I had the recovery disks, that might be a bit helpful.


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