This laptop has a power problem. The battery stops charging when I move the power cord on the DC adapter. When I start moving the cord left to right, the power LED light on the front goes on and off and the battery charge LED goes on and off too.
I removed the battery and tested the laptop again. The laptop starts fine from the DC adapter when the battery is removed, but as soon as I start moving the power cord the laptop shuts off. It looks like the laptop looses power immediately.
If you have a problem like that, most likely it’s related either to the power adapter or the DC-IN power jack.
First of all, I tested the power adapter with a multimeter. The power didn’t cut off no matter how badly I moved the cord. The power adapter output voltage was 15.45VDC all the time. That means there is nothing wrong with the power adapter and most likely there is a problem with with the power socket inside the laptop.
By the way, I just purchased a brand new FLUKE 179 multimeter here for less then $160. The retail price at Sears for the same multimeter is $240. FLUKE is a really good brand. Just a side note.
Now I’m going to test the power socket inside the laptop.
In order to access the power socket I had to disassemble the laptop and remove the top cover assembly with the display.
You can find disassembly instructions for many HP, Dell, IBM, Lenovo, Sony and Toshiba laptops in these service manuals and guides.
In the laptop I was fixing (Tecra M2) the power jack is attached to a DC-IN harness and this harness can be unplugged from the motherboard.
As you see, I removed the DC-IN harness from the motherboard, plugged in the power adapter and tested continuity with my multimeter as it shown on the picture.
When the power cord is still, the voltage output is 15.45VDC, the same as on the plug.
But as soon as I start wiggling the plug inside the jack, the power cuts off and voltage goes to 0. It means, the power harness is bad.
The problem was fixed after I replaced the defective DC-IN harness with a new one.
In some laptops the power socket (DC jack) is soldered to the motherboard.
If the battery stops charging when you wiggle the power plug inside the jack, either you have a bad power adapter (test it with a voltmeter) or the power jack is broken or loose.
You cannot simply unplug the jack and replace it with another one. You’ll have to unsolder the old jack and solder a new one back on the motherboard as I described in this post.
If the power jack is not broken but loose (not making good contact with the motherboard) you can resolder the old jack without replacing it with a new one.
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January 26th, 2009 at 9:13 pm
CAMILO LOPEZ,
I don’t think that you can reprogram the BIOS at home. Sounds like your bios is screwed and it’s necessary to replace the motherboard.
January 25th, 2009 at 7:11 pm
I have a hp laptop ze5155 pavilon, weeks ago I did a BIOS uptate but I think than install the program wrong, now the laptop no have image, does not display the HP logo. Please I need your help to know how I can fix it and reinstall the original bios of the machine
thanks
January 15th, 2009 at 5:12 am
some of the circuitry of my motherboard has come off where the power connection goes, would it work if i connect my power supply through the battery terminals (with batterys removed) the laptop is a packard bell E2316
cheers
Maggyni
December 23rd, 2008 at 7:45 am
I came across a similar problem with an acer travelmate laptop. I tested the power cord first and found out that it wasn’t faulty, but it was damaged in the process (don’t ask how
)
I found a Toshiba cord with the same plug and it looked like it supplied power – although with interruptions, as before (and in your example). My question is, do you think I can keep using the Toshiba power cord if I replace the power jack (DC in harness). The voltage is the same, but I’m not sure about other specs.
Thanks
November 24th, 2008 at 4:27 am
Is it possible to connect the power adapter directly to the battery terminal as my laptop runs on battery but not on the mains.
October 4th, 2008 at 6:15 pm
Do you have any tips for using a multimeter with an ac adapter? As in, the correct placement for the red and black leads?
September 11th, 2008 at 12:26 pm
My computer would only work when I fiddled around with the adapter so that it was at a certain angle. After a while, that stopped working as well. I had this problem before and dell sent me a new adapter. Is it more likely that the problem is with the jack? Will a new adapter (much cheaper and easier to obtain) solve the problem a second time?
September 9th, 2008 at 6:11 pm
Renee,
That could be related to the power jack OR power adapter cord. It’s possible that one of the wires inside the power cord was damaged and you had to bent the power cord in order to make the connection.
Did you ask the repairman if he tested the power adapter? Maybe your adapter is dead?
September 9th, 2008 at 6:03 pm
Chris,
Will it run from the power adapter when the battery is removed? Maybe the battery is shorting something?
Also, I guess it still could be related to the power adapter. Maybe it’s not working properly under load. Can you test the laptop with another adapter?
If not the battery or adapter, then most likely it’s the motherboard problem.
September 7th, 2008 at 7:32 am
I took my HP laptop into a repair shop to have the DC/IN power jack replaced. The computer would turn on and function fine only if I had the power cord bent at a certain angle when I took the laptop in. I received a phone call from the repairman, “We replaced the jack and we still couldn’t get the computer to turn on. We think your motherboard is fried.” I think it’s fair that I pay the $30 part fee, but is it fair that I pay the $90 labor fee if the repairman “fried” my motherboard in his attempt to install a new jack?
Thanks,
Renee