Latitude C840 AC Adapter issue, CPU issue ... Replacing the AC Adapter would be the first thing I'd try. Yes, we know what the adapter is SUPPOSED to be. So t ...

kd5 · 11-20-2009, 01:55 PM

Working on a Dell Latitude C840, 1.8ghz Pentium M, 256mb PC2700 (upgrading to 512mb), 40gb hard drive, purchased at some kind of "emporium" or some such. The AC Adapter is model ADP-90FB, 90W, bios reads it as a 70W adapter, reports that the laptop should be using a 90W adapter (which it is) and that the computer won't run as it should, as such, and to press F1 to continue booting into battery saving mode (whatever). I've updated the bios which didn't change a thing.

Also, once up in Windows (XP Professional), System Properties reports the CPU correctly but claims it's running at 789mhz on AC. Adjusting the power options (Always On) makes no difference, disabling 'Smart CPU Mode' on AC, and setting 'CPU On AC' to Maximum Performance, in the bios, made no difference either.

Can these 2 issues be related? Other than this, the laptop runs just fine...

Thanks, -kd5-

dave-p · 11-20-2009, 07:30 PM

you most likely require a new adaptor

powerpack · 11-20-2009, 07:50 PM

As a desperate guess try without battery in? But yes if the adapter is 70w sure could be the issue.

kd5 · 11-21-2009, 05:49 AM

Even if the current adapter is actually (supposed to be) 90W, you think replacing it will cure the problem? -kd5-

dave-p · 11-21-2009, 05:51 PM

it should yes

MrEvil · 11-22-2009, 02:08 AM

Replacing the AC Adapter would be the first thing I'd try. Yes, we know what the adapter is SUPPOSED to be. So the next logical step in troubleshooting would be to determine if it's the computer's problem or the Adapter's.

kd5 · 11-22-2009, 06:04 AM

For everything there is a first time and this is a first for me. I always assumed when an AC Adapter went bad it was toast. Until now I didn't know there were shades of gray to consider. I am always proud to learn new things, the day I stop learning is the day I die.

Thanks guys, -kd5-

qhn · 11-22-2009, 10:23 AM

Ouch, you would not want to have a toasted AC Adapter ... when that happens, it might also toast some other stuffs in the notebook

cheers ...

11-20-2009, 01:55 PM	#1
kd5 Registered Lunatic Join Date: Jul 2005 Location: Ohio Posts: 6 Credits: -108	Latitude C840 AC Adapter issue, CPU issue Working on a Dell Latitude C840, 1.8ghz Pentium M, 256mb PC2700 (upgrading to 512mb), 40gb hard drive, purchased at some kind of "emporium" or some such. The AC Adapter is model ADP-90FB, 90W, bios reads it as a 70W adapter, reports that the laptop should be using a 90W adapter (which it is) and that the computer won't run as it should, as such, and to press F1 to continue booting into battery saving mode (whatever). I've updated the bios which didn't change a thing. Also, once up in Windows (XP Professional), System Properties reports the CPU correctly but claims it's running at 789mhz on AC. Adjusting the power options (Always On) makes no difference, disabling 'Smart CPU Mode' on AC, and setting 'CPU On AC' to Maximum Performance, in the bios, made no difference either. Can these 2 issues be related? Other than this, the laptop runs just fine... Thanks, -kd5- __________________ Time is the fire in which we burn. ~Soran~ Last edited by kd5; 11-20-2009 at 01:57 PM.

11-20-2009, 07:30 PM	#2
dave-p Loving my Alien :) Join Date: Feb 2006 Location: Ontario, Canada Posts: 14,181 Reviews: 2 Benchmarks: 8 Credits: 102,676	you most likely require a new adaptor __________________ M17x, FX Red, QX9300, Sli GTX-280, 256GB SSD, 4 GB DDR3 1333 Mhz 3yr CC M6400, Q9000, FX3700, 8GB DDR3, RGB LED Display, HD, Blu Ray, 1530 WiFi 370 BT, Desktop Water Cooled I7 975 Extreme, X58A-UD3R, RX1200 Watt PSU, 12 GB DDR3, 2 TB Raid 1, Dell 2707, Blu Ray, GTX 295 CO-OP Copper, Swiftech GTZ, My Dells Vostro 1500, Studio 15, M6300,M1710, E1705,3500,4000,4100,5100,5150,6000, 7000,7500,8000,8500,C410,C610,C810,Cpi,CPx. 6400,1501

11-20-2009, 07:50 PM	#3
powerpack Registered User Join Date: Apr 2009 Location: Chicago Baby! Posts: 2,652 Credits: 5,332	As a desperate guess try without battery in? But yes if the adapter is 70w sure could be the issue. __________________ *Going To Order* G73JH-A2 i7 720QM 1.6Ghz/HD5870 1GB/8GB RAM/2x500GB HDD's

11-21-2009, 05:49 AM	#4
kd5 Registered Lunatic Join Date: Jul 2005 Location: Ohio Posts: 6 Credits: -108	Even if the current adapter is actually (supposed to be) 90W, you think replacing it will cure the problem? -kd5- __________________ Time is the fire in which we burn. ~Soran~ Last edited by kd5; 11-21-2009 at 06:20 AM.

11-21-2009, 05:51 PM	#5
dave-p Loving my Alien :) Join Date: Feb 2006 Location: Ontario, Canada Posts: 14,181 Reviews: 2 Benchmarks: 8 Credits: 102,676	it should yes __________________ M17x, FX Red, QX9300, Sli GTX-280, 256GB SSD, 4 GB DDR3 1333 Mhz 3yr CC M6400, Q9000, FX3700, 8GB DDR3, RGB LED Display, HD, Blu Ray, 1530 WiFi 370 BT, Desktop Water Cooled I7 975 Extreme, X58A-UD3R, RX1200 Watt PSU, 12 GB DDR3, 2 TB Raid 1, Dell 2707, Blu Ray, GTX 295 CO-OP Copper, Swiftech GTZ, My Dells Vostro 1500, Studio 15, M6300,M1710, E1705,3500,4000,4100,5100,5150,6000, 7000,7500,8000,8500,C410,C610,C810,Cpi,CPx. 6400,1501

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11-22-2009, 02:08 AM	#6
MrEvil The Dr House of PC repair Join Date: Feb 2006 Location: Amarillo TX Posts: 4,451 Credits: 148	Replacing the AC Adapter would be the first thing I'd try. Yes, we know what the adapter is SUPPOSED to be. So the next logical step in troubleshooting would be to determine if it's the computer's problem or the Adapter's. __________________ Notebook Forums' resident Dell/IBM/Sony field service technician. My Notebook: Dell Latitude D820 \| Intel Core Duo T2500 \| 2GB DDR2 \| 15" WSXGA screen \| nVidia Quadro 120m \| 250GB Hard Drive \| Samsung DVD-RW drive My Netbook: ASUS Eee(vil)PC 1000HE upgraded to 2GB of RAM running Windows 7 My Desktop: Intel Core 2 Quad QX9300 @ 3.5Ghz Liquid cooled \| 4GB Corsair Dominator DDR 1066 \| ATi Radeon 4870 \| Western Digital Velociraptor 300GB \| ASUS Maximus Formula motherboard \| Vista Ultimate x64

11-22-2009, 06:04 AM	#7
kd5 Registered Lunatic Join Date: Jul 2005 Location: Ohio Posts: 6 Credits: -108	For everything there is a first time and this is a first for me. I always assumed when an AC Adapter went bad it was toast. Until now I didn't know there were shades of gray to consider. I am always proud to learn new things, the day I stop learning is the day I die. Thanks guys, -kd5- __________________ Time is the fire in which we burn. ~Soran~

11-22-2009, 10:23 AM	#8
qhn ... am invisible Join Date: Mar 2006 Posts: 26,664 Reviews: 9 Benchmarks: 18 Credits: 74,627	Ouch, you would not want to have a toasted AC Adapter ... when that happens, it might also toast some other stuffs in the notebook cheers ... __________________ m6805@3700; SZ71WN/C ; Macbook 2ghz/4gig/250gb/superdrive; 7811FX are u Folding@Home? - Firefox Beta - MediaPortal "the" Media Centre/HTPC!

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