I have a compaq s6500nx that will reboot itself intermittently. It will power itself on all by itself when shut down for 20 minutes or so. Sometimes it just loops, starting and shutting down. I think it is a motherboard or power supply issue, but am looking for some advice.

follow this steps and fix it. God bless you

Float Switch

The float switch may be hung up and this can cause the dishwasher to be stuck in a cycle. Check the tutorial and the video for checking this part.

Timer / Control

If your dishwasher gets stuck in a cycle first try shutting off the breaker for at least 5 minutes if this does not correct the problem you will need to replace timer/electronic control board.

DO NOT ATTEMPT ANY REPAIRS, CALL THE FACTORY PHONE NUMBER IN THE OWNERS MANUAL AND FIND OUT WHERE TO HAVE THE TV SERVICED, IF YOU ATTEMPT ANY REPAIRS THEY WILL VOID THE FACTORY WARRANTY. THIS IS CAUSED BY AN ELECTRICAL FAULT INSIDE THE TV, IT SHUTS DOWN AS A SAFETY FEATURE TO AVOID ANY FURTHER DAMAGE.

is the processor fan spinning and dose it get to full speed because it sound like its over heating and shutting down

If the Compaq doesn't power on with the Power On switch, bypass the Power On switch.
This test will also tell you whether the Power On switch is bad, or the Power Supply.

1) First I suggest you check THAT receptacle IN the surge protector, that the computer is plugged into.

I have had a few surge protectors where just THAT receptacle was bad.


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

Upon plugging a lamp into THAT receptacle in the surge protector, that the computer was plugged into, proved that receptacle to be bad.

2) To bypass the Power On switch:

A) If you bypass the Power On switch, and the computer turns on, (Power Supply turns on), you have a bad 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,

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

B) If you bypass the Power On switch, and the computer does not come on, the Power Supply is bad.
Replace.
This you can do yourself easily. More on this later.

You won't be touching the wires of the Power On switch.
You will be addressing the power wires in the 20-pin ATX main power cable, and it's connector.

This is a 20-pin ATX main power cable, and the connector on the end of the cable,

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

The Compaq Presario S6500NX uses a 20-pin ATX main power cable.

This is HP Support > Compaq Presario S6500NX desktop computer > Specifications > Motherboard Specifications,

http://h10025.www1.hp.com/ewfrf/wc/document?docname=c00063254&tmp_task=prodinfoCategory&lc=en&dlc=en&cc=us&lang=en&product=390429

I would like you to scroll down to the illustration of the motherboard, (Asus A7V8X-LA), and to the photo of the motherboard underneath the illustration.

{By the way. If you look at the photo of the Compaq Presario S6500NX at the top right of the page, you will see it isn't accurate. Shows the computer case to be almost square shaped. NOT}

Looking at the motherboard illustration view the Ram Memory slots.
They are marked as DDR DIMM 1 (64 bit, 184-pin module), and DDR DIMM 2 (64 bit, 184-pin module)

To the right is the 20-pin ATX main power cable connector, on the motherboard. It is marked as ATX Power Connector.

Matching it up on the photo, it is the white rectangular connector that has two columns of square socket holes.
10 socket holes per column. 20 total.

When you open your computer case, you will see the ATX main power cable plugged into this white connector.
It will look similar to the photo at the far right in the above Playtool link.

To bypass the Power On switch you will use a jumper wire, to briefly connect the Green wire, and ANY Black wire.

The Green wire is the Soft Power On wire. (PS_ON)
ANY Black wire you see is a Ground wire.

Use a paper clip straightened out, then bent into a U-shape.
The middle of the U-shape is wrapped with electrical tape.
This is where you hold the jumper wire.

The voltage is 5 Volts DC.
Two D cell flashlight batteries produce 3 Volts DC.
As you can see it isn't a large voltage at all.
You may wish to don a glove on the hand holding the jumper wire.

There may, or may not, be a spark when you make contact with the jumper wire.
Want you to feel safe.
(1 wrap of electrical tape is good enough for 600 Volts DC. Just wanted you to know. Wrap the U-shape jumper wire thick enough so it is easily held by your finger, and thumb)

The jumper wire goes down into the socket hole with the power wire. Goes down right next to the plastic insulation of the wire, and down into the socket hole.

At the end of every power wire going down into the ATX main power cable's connector, is a metal terminal connector. (Female)
The insulation of the power wire goes down into the socket hole pretty deep.

You need to ensure that the jumper wire touches the metal terminal. The jumper wire has to go down in the socket hole until it touches the metal terminal connector.

On end of the jumper wire goes down in the Green wire's socket hole.
The other end of the wire goes down into ANY Black wire's socket hole.

The contact is brief. Works on the same principle as the Power On switch.
The Power On switch is a Momentary Contact Switch.
Touch for no more than two seconds, lift the jumper wire out of the socket holes.

Computer comes on?
Bad Power On switch.

Computer does not come on?
Bad Power Supply.

The Power Supply used in a Compaq Presario S6500NX is an ATX power supply.
(It's also a SMPS if you want to get technical.
Switched-Mode Power Supply)

Uses the ATX Form Factor.
The form factor used by MANY personal computers.
Very readily available.

[ATX Form Factor for a Power Supply's case, is the size, and shape of the case.
Approximately 6 inches Long, 6 inches Wide, and 3-1/2 inches Tall]

It's a 250 Watt power supply, and is a generic unit.
Probably made by Bestec, Delta, or the like.
Maximum rate Wattage is stated at 250 Watts.
Actual maximum wattage for a Power Supply made in this time period, is more like 60 to 70 percent of what is stated.
150 Watts to 175 Watts.

The power cables needed will be supplied with the new Power Supply's.
New power supply's have an ATX main power cable that can be used as a 20-pin ATX main power cable, or a 24-pin ATX main power cable.

They will also come with a 4-pin ATX +12 Volt power cable.
(Usually described by the seller as a P4 12V power cable, or P4 MB)

http://www.playtool.com/pages/psuconnectors/connectors.html#atx12v4

This is one example of a Power Supply that has enough Wattage, correct Form Factor, and correct power cables,

http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=1621514&CatId=1078

Information on how to replace a Power Supply,

1) http://www.fonerbooks.com/r_power.htm

2) http://support.gateway.com/support/manlib/cmponts/process/8508750/08750c01.htm

From me:
Power unplugged from computer, be SURE to follow Anti-Static Precautions BEFORE reaching inside a computer.

Anti-Static Precautions:
Your body carries Static electricity.
Static will fry out (Short Circuit) the hardware components inside a computer.

To relieve your body of Static:
Computer unplugged from power, computer case open, TOUCH the metal frame of the open computer case.

If you get up, and walk away from your computer in the middle of working on it, be SURE to touch the metal frame again upon your return.

For questions please post in a Comment.

Your harddrive is starting to go. You will need to replace your hard drive. When you computer starts running slow then it reboots itself is because it is trying to get itself to work properly, but the hard drive is not operating at full capacity. I would back up all of your files as soon as you can onto either a CD or a flash drive, to save yourself from very costly repairs if you need to have the data extracted from the hard drive

if you need your laptop always in ready use change the time your computer is on in control panel then log off your device will be on always until you shut it down it constantly drains battery
There is a way to fix this try reinstalling windows
or just take it to software mechanic

The other way is to remove the BIOS battery and let it stand for 20 plus minutes, then insert the BIOS battery back into the computer. The BIOS settings will then be returned to the factory default settings, you then need to go into the BIOS setting and change the Date and Time setting.

sounds like you have board problems.
unplug everything from it first and see if this helps could be something you have plugged up could be bad too.
you will have to open box and look for damage and then one by one unplug something and then reboot to see what it might be.

found cold connection on board at tuner