1) DO NOT unplug the AC adapter from the laptop, while the AC adapter is plugged into power.
Good way to get a voltage spike, and burn out the power correcting chipset.
Some have performed this for years, but one day.............
2) The plug from the AC adapter, plugs into the DC Power Jack on the laptop.
On the laptop it may have DC_IN marked next to it.
Let's look together at the DC Power Jack, for the HP Pavilion DV8T-1200 Notebook PC,
The actual DC Power Jack is on the left side. Apologies that the photo isn't clearer.
It connects to the cable shown, and the cable connects to a connector. (Right side)
With this model it is a DC Power Harness. All one has to do is partially disassemble the laptop, and replace it.
Disconnect the small white connector, shown on the right side. It plugs into the motherboard.
The actual DC Power Jack resides in a channel on the outside edge of the laptop.
This is a link to a free Service Manual, for the HP Pavilion DV8 series of Notebook PC's,
(Of which the Pavilion DV8T-1200 is one of),
Scroll down to the subheading - HP Pavilion dm1. (dm1 in blue)
Scroll across, and click on DV8.
[ Disregard the following if you are aware;
This is a PDF file. The computer you are using now has Adobe Reader on it, which uses PDF files.
After you click on the file name, (DV8), it may take up to 30 seconds, before the first page comes up ]
In the Bookmarks menu to the left, click (Left) on the + sign next to - Removal and replacement procedures
Scroll it down, click right on - Power connector cable
In the list under the number 5, you'll see the components that need to be removed, before you can replace the Power Connector Cable.
(DC Power Harness. HP? Power Connector Cable )
These components are listed in alphabetical order. You will also see they are highlighted in blue. This means you just click on each one, one at a time, and be taken directly to the page section that deals with it. Then go back to the original page. (Page 92)
BEFORE beginning; Observe Anti-Static Precautions.
Your body carries Static electricity. Static WILL fry out, (Short Circuit), the delicate hardware components inside a computer.
With a laptop I encourage you to wear an ESD wrist strap, and have it's alligator clip connected to a good ground source.
Price of an ESD wrist strap averages around $3 to $6. Much cheaper than laptop replacement.
A) Use a multi-compartment container for the various screws you will remove. Label each compartment for the area the screw/s come out of.
SOME screws look VERY similar to other screws. DO NOT mix them up.
(There is a screw list in the Service Manual also)
B) Make a record as you disassemble. It's nice to have a Service Manual, but even nicer to have your own personal record to refer back to, in case you are interrupted.
Make notes, and drawings. Also you may wish to use a digital camera, or video camera. (USE good lighting. Make legible notes)
C) Have a problem along the way? Post back here. You know where you can find me.
The only problem I have is being too detailed. I like to explain as if I'm sitting next to you.
NO question is stupid. If you ask it, I will answer it.
Do I think this is the problem? The only way to find out is to diagnose, and this is what we are doing.
Once the Power Connector Cable is removed, I suggest you purchase an inexpensive multimeter; if you do not own one, or have access to one.
An inexpensive multimeter that is good enough for the following tests, averages around $8 to $12.
A multitude of stores carry them. An auto parts store is but one example.
Analog or digital is fine.
The DC Power Jack in that harness has two connections. The center pin is the Positive connection. The inner cylindrical metal shell, is the Negative connection. (This is DC electricity we are dealing with)
You are going to perform a continuity test of the Power Connector Cable.
See if there is electricity going through it, or there is a break in the wire. Also see if there is damage to the DC Power Jack.
Use a non-metallic object, and see if you can move the center pin around, in the DC Power Jack.
ANY perceptible movement means replacement of the Power Connector Cable. (Damage)
Set the Function knob of the multimeter to Ohms. (Omega symbol)
Hold the Positive probe lead of the multimeter, (Red) to the center pin. Go to the connector at the end of the cable, and touch one of the small contacts with the Negative probe lead of the multimeter, (Black). No reading on multimeter? Go to the next contact, and so on.
IF, touching all contacts, one at a time, gets no results, you have a broken wire in the cable.
Multimeter shows there is continuity for the center pin to contact? You may also want to have an assistant gently wiggle the cable, and see if there is an intermittent reading on the multimeter. This indicates a broken wire.
(Same with the metal shell inside the DC Power Jack)
Power Connector Cable checks out?
Hardware components on the motherboard may have been shorted out from a voltage spike. Pulling the AC adapter's plug out of the laptop, while AC adapter was plugged into power.
If this is so, the power correcting chipset took a hit. (It's bad)
This is a type of Power MOSFET. In this case motherboard replacement is a more viable alternative, than trying to find that chipset on the motherboard, purchasing it, and Correctly replacing it.
[ Chip and Chipset are slang terms for I.C.
This is but one example of a chipset used for the above,
Best bet in this case is to replace the motherboard.
3) IF, you think the AC adapter is bad, suggest you test the AC adapter before rushing out to buy a new one.
The center hole is Positive. The outside cylindrical metal shell is Negative.
The voltage is 18.5 Volts. (DC)
Set the multimeter's Function knob to DC Voltage. If just a symbol, the symbol is a dotted line over a solid line.