My laptop isnt powering on. a friend replaced the power plug inside, and now there is no power. Also what does the jumper/connector j4402 near the cmos battery connect to?

From memory, there is no jumper. Look for bare solder pads near the bios battery... usually marked 'RST' or 'FRST' or similar. There will be a few pairs of pads grouped, you only need to short out the RST ones (a pair) Its a bit of a juggling act, but short them out during the process of applying power to the laptop. so... short out, maintain the short, plug in power, power up laptop, maintaining short for about 3 seconds..... remove power, restart.

shut down your computer remove the power plug and open the cover near the c mos battery you will see a three pin connector with two pin shorted with a jumper remove the jumper and replace the empty pin then the c mos then restart ur computer in some cases the computer may not work then switch off and replace the jumper back into the original position
it will reset the start up password

Dunno yet.
I suggest you perform the diagnostic test to see if the problem is the Power On switch, (Located inside the plastic Power On button assembly), or the Power Supply.

(Hopefully your power company wasn't doing any work on your line, or a brownout occurred. Also hope there were no lightning storms present, and the computer was plugged in. Surge protector? With lightning strikes you need a surge protector that costs around $300. The ones that are usually purchased will not provide adequate protection. No matter what they state. {$12 to $60)

The method is to use a jumper wire on the ATX main power cable connector.
The jumper wire connects to the green Soft Power On wire, and ANY black ground wire.

If the computer comes on, (Power Supply actually), you have a bad Power On switch.
A generic replacement Power On switch runs about $5,

http://www.directron.com/atxswitch.html

If the computer does NOT come on you have a bad Power Supply.
(Not hard to replace yourself at all)

I would like to start by showing you an illustration and photo of your motherboard,

http://h10025.www1.hp.com/ewfrf/wc/document?docname=bph07813&tmp_task=prodinfoCategory&lc=en&dlc=en&cc=us&site=null&lang=en&product=329403&key=null

Scroll the page down towards the bottom.
There is a square shape represented in the middle of the illustration, with the bold letter/numbers - Intel 845GL in it, and Memory Controller Hub (MCH) under that.

Below this is the ATX main power connector. (ATX Power Connector)
It is white in color (Photo), and has 20 socket holes.
Two rows of 10 socket holes.

This is a closer look at an average 20-pin ATX main power cable, and it's connector. (Plus the above mentioned connector on the motherboard),

http://www.playtool.com/pages/psuconnectors/connectors.html#atxmain20

The photo to the far Left shows the 20-pin ATX main power connector on the motherboard. (Female connector)

The photo in the Middle shows the Front of the connector, on the power supply's 20-pin ATX main power cable. (Male connector) Plugs into the connector on the motherboard.

The photo to the far right shows the 20-pin ATX main power cable plugged into the motherboard.
(into the 20-pin ATX main power connector on the motherboard)

The photo to the far Right shows the BACK of the connector that you will be using.
The jumper wire is placed down into two socket holes into the Back of the connector.

One end of the jumper wire goes down into the socket hole with the Green wire.
The green wire is the Soft Power On wire. (Abbreviated as PS_ON)

The other end of the jumper wire goes down into a socket hole with ANY Black wire.
ALL Black wires are ground wires.

The jumper wire goes down into the socket hole RIGHT NEXT TO THE EXISTING WIRE that is present.
Goes right beside the wire already in the socket hole.

Every wire going down into that connector ends in a metal terminal.
The metal terminal is pretty far down into the socket hole.

For this reason, you must ensure that the ends of the jumper wire are touching the metal terminals, down in the socket holes.

A paper clip is usually used for the jumper wire. It is nice and thin, conducts electricity, and is stiff.
The paper clip is straightened out, then bent into a U-shape.
The middle of the U is wrapped with a few wraps of black plastic electrical tape.
This area is for your fingers.

Computer laying on it's side on a table, computer case open, computer plugged into power:
The jumper wire is inserted into the two socket holes mentioned above.

IF the computer comes on you have a bad Power On switch.
If it does NOT you have a bad Power Supply.

About the voltage you will be addressing.
1) One wrap of black plastic electrical tape will insulate you from 600 Volts DC.

2) The voltage you will be addressing is 5 Volts DC.
Two D cell flashlight batteries produce 3 Volts DC.

3) There may be a spark. Cautioning you in advance. You may wish to wear a rubber dishwashing glove on the hand with the jumper wire.
(Sometimes there is no spark. Just cautioning you in advance so you don't freak out)

[Your computer Power Supply converts AC electricity from your home, or business, into DC electricity. (100 Volts AC, 120 Volts AC, or 220 Volts AC. Depends on what country you live in )

DC electricity is what is used by the hardware components inside the computer.
There is 3.3 Volts present, 5 Volts present, and 12 Volts present.
Only if you stick your hands inside an open computer power supply, (and plugged in), would you get shocked ]

For additional questions please post in a Comment.
Regards,
joecoolvette

Suggest you see if the problem is the Power On switch, or the Power Supply.

(First check to see if the receptacle in the surge protector, that the computer is plugged into, has power.
Have had a few bad surge protectors, where just THAT receptacle was bad.

"Hmmm, surge protector power on LED light is lit. Monitor, printer, and router have power, that are plugged into the surge protector.

Plugged a lamp into THAT receptacle, and found it to be bad)

To test whether the Power On switch, or the Power Supply is bad, a jumper wire is used to bypass the Power On switch.

[ The Power On switch is located inside the plastic Power On button.
This is an example of a generic ATX Power On switch, that I have found fits many computers,

http://www.directron.com/atxswitch.html ]

The jumper wire is used on the 20, or 24-pin ATX main power cable's connector.
While still plugged into the motherboard.

The jumper wire connects to the Soft Power On wire, (Green), and to any Ground wire. (Black)

Example of a 20-pin ATX main power cable, and it's respective connector,

http://www.playtool.com/pages/psuconnectors/connectors.html#atxmain20

Example of a 24-pin ATX main power cable, and it's respective connector,

http://www.playtool.com/pages/psuconnectors/connectors.html#atxmain24

Using the jumper (Wire) to bypass the Power On switch, turns the Power Supply on?
The problem is a bad Power On switch.

Using the jumper to bypass the Power On switch, does Not turn the Power Supply on?
The problem is a bad Power Supply.

There is a correct procedure for performing this test.
Post back in a Comment if you wish to know.

Regards,
joecoolvette

hi
you might be right.try testing it with another hp pavillion power cord.if you are still experiencing this problem then your power pack is faulty.and you should have it changed

Goodluck!!

Dear friend not required any jumper setting. Just remove the battery from laptop then plug in adapter with your laptop. Power on and use. But remember when you use your laptop without battery a sudden power cut may cause of damage of your Operating System & you can not save running unsaved documents.
Thanks.

There are 2 ways to clear CMOS on any desktop PC.

1st There will be a set of 3 pins near the motherboatd battery with a jumper across them. Move the jumper over and wait 30 secs then move back. Remember to remove the power cable first.

If you can't find the CMOS pins and jumper then remove the power cable and also the 24 pin motherboard power connector and the motherboard battery and leave for 24 hrs.

Replace battery etc and away you go.

Why do you want to clear the CMOS?

If the power adapter is not charging your laptop but it chargers a friends, then that means the DC input jack inside your laptop has either broken off, gotten pushed in, or has otherwise been disconnected. Unfortunately you will need to have the machine serviced. Your best bet would be to call Compaq support.

check your IDE or sata connected properly inside your CPU...

had the same problem myself, the dc connector gets corroded, the metal strip down the side inside the dc connector. over time it needs bending back towards the center pin. clean off the connector inside with something. thats what i did ant the customer is happy as anything