Hey,
my mate and i built my computer (mate is the techy) and i took it apart the other day to clear all the dust from the fans in the computer. before doing this i took photos and drew pics to make sure that id plug cables back in the right places. after i cleaned it and put it back together i started it up and it started, beeped as usual and then beeped twice and shut down. i spoke to my mate who is away for a week and he sed that i havent connected something. i went back over the comp several times referring to pics and drawings and i cant find what im missing.

i have 2 cables goin to the motherboard, 2 cables to the video card connected by a dual connector, power to the dvd ram drive, power to the HDD and then to all he case fans and lights etc.

any ideas?

btw i have an ASUS P5GD1 PRO motherboard, a 500w PSU, and an ati radeon X800 xt pro vid card.

regards Tom

ummm - you havent connected something.
Lets see the before and after photos.
Also did you make sure to ground yourself to the case as you were tinkering around as the cat was away?

It sounds like you don't know enough about computers to be doing what you did.

Your first resource is your mboard manual - it's on the CD that came with the mboard, probably a *.pdf document.

A search of the web for: beeps twice shuts down
yielded these bits of info:

With an AWARD BIOS, 2 short beeps signify any type of Non-Fatal Error.
(your mboard probably has an Award bios)
This can be caused by a number of things, it can be faulty RAM, or it can be that the processor is overheating. You may want to check and see if the Heatsink CPU fan is working. If it is working then it may be slowing down considerably at times which would cause the CPU to overheat and cause the computer to abnormally shut down.

Two beeps means that incompatible RAM types may be installed.

So.....
REMOVE the power to your case, and make sure all your cards, ram, and connectors are fully seated (all the way down in their slots, or on their pins). The latches at the ends of the ram slots should be latched, that is, against the ends of the modules.
Make certain the ram is in the right slots - if you took photos that should be apparent - or look at the mboard manual - on some mboards if the ram is not in the right slots it may be detected as incompatible.

Make sure the 3 wires from the cpu fan are connected to a three pin header on the mboard for the cpu fan, not some other fan header. Some mboards will shut down in a few seconds if no fan rpm is detected from the cpu fan header.

Plug in the power to the case, but don't touch anything inside the case while it's plugged in. Make sure the cpu fan is spinning at a reasonable speed and that it is not making screeching or rattling noises.

If that doesn't help you could try cleaning the contacts on your ram.
REMOVE the power to your case
Remove the ram and clean it's contacts with isopropyl or methyl alcohol, or if you don't have either of those a solution made with a tiny drop of dish detergent in water will do. Wipe off the contacts with a tissue to make sure they are dry. Don't touch the contacts with your fingers after that. Check the ram slots for mung - blow out or brush out (e.g. with a tiny artist's paintbrish)any you mung you see. Insert the ram making sure it is the right way and fully seated, latch the latches.
The notches in the contact edge on the ram modules MUST line up with the bumps in the ram slots - if you install the module backwards, the latches will be difficult or impossible to latch on one end or both ends, and if you try to boot the computer with the module backwards, the module that is backwards will FRY instantly, the ram slot it is in will FRY instantly and vaporize some of the contacts in the slot and that slot can never be used again, even if you clean up the melted plastic, carbon, and any bridged contacts in that slot.

If none of that helps, it could be any of many other things are wrong.
Consult the manual for the mboard to make sure everything is connected properly.

ok, so i did what tubesandwires suggested. now itll start up, sometimes on the bios screen itll say cpu overclocking failed then shutdown (which doesnt make sense cause i havent overclocked my cpu at all) then the other times itll load past the bios to another screen saying hardware or software changes occured and windows did not shutdown properly, then i have to choose a mode to start in. usually my comp cuts out b4 i get a chance to choose. there was the odd occasion when it stayed on and loaded XP all the way to the login screen and i logged in and then it cut out. but most of the time it just cuts out in the middle of loading XP

ideas???

regards tom

Well, at least it's doing something now.

Did you remove the mboard battery while cleaning then put it back in?
If you did, the polarity ( + and - ) must be correct - usually you can see a + on the top of the battery if it is correct. Also the contact fingers in the battery holder must be touching the battery.
If you did remove the battery, use some good light to look.

If you did remove the battery, the first time you boot after that you will get a "Cmos Checksum Error...." or similar message. You will either be prompted to enter the bios Setup or you will automatically go there. Enter the bios Setup, set the time and date, and Save settings, and the "Cmos Checksum Error...." message should not appear the next time you boot and thereafter.
If the message continues to appear, the battery polarity is backwards, or the contacts are not touching it properly.

Were you fiddling with any bios Setup settings?

Did you move any jumpers on the mboard, as in, tiny ones that have no wires on tiny pins?

If no to all of the above, what was the reason you felt you had to clean the inside of the computer?
Was it because it was randomly rebooting?

The two most common reasons for hardware caused unexplained rebooting are:
- a failing power supply
Failing power supplies are common and can cause your symptoms.
Check your PS.
See response 4 in this:
http://www.computing.net/hardware/w...

- or an overheating or damaged cpu.

A faulty power supply can cause problems at any time.

Normally overheating does not cause any problems until the computer has warmed up some. If the cpu fan is spinning fine and the fan and the heatsink are faily clean, the cpu should not overheat.
However, if the cpu fan was or is not spinning very well, or the cpu fan and the cpu sink were really dirty before you cleaned them and the cooling of the cpu was poor because of that, it is possible the cpu is damaged.

im having my mate come around tonight to have a look at my comp. no i didnt remove the battery. and i took it all apart because it was really badly dusty and yes the heat sink on the cpu was extremellly clogged with dust. in the process of cleaning i didnt remove my cpu at all, and my comp didnt reboot randomly before. so im really hoping my cpu isnt damaged and my comp will be up and running tonite. also no i didnt remove or change and jump pins. i went throught my motherboard manual and checked everything including this.

regards tom

Ok. Your mate should be able to help you.

If it is hardware causing the problem, it sounds like in your case it is most likely caused by a failing PS.