No power

By vietdraz
Jan 8, 2004
  1. I'm new to the computer world, and need help. My HP Pavilion is only a few months old, 2.66 GHz Pentium 4. Last time that it was on, i was on stand by and I shut it down, now it won't turn on at all. There is no power to the computer, thus, it won't turn on. the light in the back of the computer that used to be on when it is off is no longer there. please help....
  2. Masque

    Masque TechSpot Chancellor Posts: 1,058

    Do you have it plugged into a power strip that might have tripped it's breaker?
  3. StormBringer

    StormBringer TS Rookie Posts: 2,244

    if there is a power switch on the back of the unit, make sure it is on, make sure the voltage selector is set to the proper line voltage for your region. Also check the Power Supply's fuse if it is accessible, if not, have a qualified technician check it(I say this because you say you are new to computers, so I wouldn't advise that you go tearing in to the PSU)

    While you're at it, check the power cable itself, disconnect it from the unit and the wall and reconnect it. If you have another computer or anything else that uses the samwe cable(fairly common these days) then swap it out, as it might be faulty.

    Oh, and just to cover all the bases, check the outlet itself if you haven't already.
  4. vietdraz

    vietdraz TS Rookie Topic Starter

    Thankx Masque & StormBringer for your replies

    I have went on-line and and did the basic steps such as check cables, power surge, etc., I have opened up the CPU and check if the Motherboard is connected, and everything seem fine. I suspect that the power supply of my computer (I don't know what it's called, it's the thing that the power cable is connected to) is down because when I attempt to turn the computer on, nothing happens, no sound, no light, nothing... Is there anyway to know if the power supply is still running? Could it be the Motherbaord that broke down instead?
  5. vietdraz

    vietdraz TS Rookie Topic Starter

    P.S. To StormBringer: Even though it is true that I am new to computers, but I am a fast learner, and willing to "tear" the computer down to find out what happens (well I've already opened the CPU up anyway.) Oh, yeah, the power switch was still on. If you suspect anything, please let me know...
  6. SubKamran

    SubKamran TS Rookie Posts: 166

    A little side note, CPU = Processor, you opened the case ;)

    I don't know how hard it would be for you to swap a power supply from a working computer? If not, BestBuy is the best :D
  7. vietdraz

    vietdraz TS Rookie Topic Starter

    I guess I'm not that good.
    Well, I can swap power supply (I've read an article on-line), but is it ok, are there different types power supply? If yes, what should I be looking for, how would I know if it is fit for my computer?

    Thanx SubKamran
  8. siggers

    siggers TS Rookie Posts: 30

    Well, make sure you get a power supply for a P4 motherboard if you're going to go buy a new one. I'm pretty sure the P4 PSU's have a extra square 4-holed connector that goes directly into the motherboard in addition to the standard power connector to the mobo. I think its additional power for the CPU or something, but dont quote me on it.

    Generally, don't go with the cheapest kind of power supply you can get...for it would be more likely to fail (as yours seems to have) in the future. Im saying this because brand-name computers like HP have a tendency to put weaker power supplies in their systems.
    A 300watt or 350watt or more brand name power supply would be great for your system.

    All in all, it's really not that hard to put in a new power supply.
    Usually, there are just four screws holding the power supply to the case. Although, you might run into a problem that i had. The screw holes on the new power supply i got didnt match up with the plate that they go through on the case. If you buy a retail power supply though, you should receive a new back plate for your case in the box.
    Take a look at the back of your computer & find those screw holes and, if need be, make a drawing of where they are & then compare that to what you are going to purchase.

    All you have to do is follow all the wires coming out of the current installed one, and make note of them.
    When you get the new power supply, take out the old one via the four (give or take) screws from the rear of the machine. Then, *carefully* unplug everything that's connected to the power supply after making note of what was plugged in where.
    Some of the connectors might be a little hard to unplug, but i find that a little wiggling back and forth *carefully* will eventually get them unplugged.

    Then, all you gotta do is put in the new PSU & make sure everything is plugged in that was plugged in before.

    Hope i havent confused you too much with my ramblings :grinthumb
  9. SubKamran

    SubKamran TS Rookie Posts: 166

    You are correct Siggers, the P4 supplies have a 4-plug connector for extra power to the CPU.
  10. StormBringer

    StormBringer TS Rookie Posts: 2,244

    Well, vietdraz, you stated in one of your replies, or maybe the original statement, that there was a light that used to be on all the time and no longer is. To add to that, many newer motherboards have a light on them that stays on as long as there is power to the machine(even if the power is off, as long as the PSU is getting power and working correctly) If your board has such a light and it is off, then thats a good indication that the PSU is dead. Don't go buy a new one just yet, you say you are OK with tearing things apart, so, if you have not yet located a fuse or breaker on the PSU, disconnect the power cable from the PSU, remove it from the computer's case and open it up(be careful, as some are difficult to open and you don't want to damage anything, there are also a couple of capacitors in the PSU that can give you a good jolt if they still have power stored in them) Look around inside the PSU for a fuse. It should be a glass type fuse that may be in a standard type fuse holder, or it could be soldered in place in some PSUs. Look at the fuse, see if it is blown, also look around and see if you see any obvious signs of damage. If the fuse is blown, simply replace it(or have it replaced if it requires soldering and you aren't comfortable with doing that)
    Once you've checked the fuse and it looks ok, or if you notice something ungood inside the PSU, then it is likely that you need a new one.
  11. Shiney

    Shiney TS Booster Posts: 157

    If the computer is just a few months old, can't you take it back for a warranty repair, or is there no warranty on the machine ?

    If you open up the case i think you will invalidate your warranty anyway.
  12. vietdraz

    vietdraz TS Rookie Topic Starter

    Thankx everyone

    Shiney: Yes, very young computer and I bought it at Costco, so it is very easy to be replaced, however, the old harddrive have much information on it including credit card numbers, and different programs that I've gotten from diferent friends, very hard now to part with it.

    StormBringer: I have read an article on surge protector, and I think you called it a breaker (hopefully it is the same thing), it is very likely that I shall give it a try. Very helpful information - man, you guys are good...

    siggers & SubKamran: Very good tips, will try after failing StormBringer's procedure

    Over and out
  13. vassil3427

    vassil3427 TS Rookie Posts: 640

    Ok, the hard drive does not lose anything if you replace the Power Supply(Two completely different things inside the computer). So dont worry, you have not lost any information...

    Either get a new Power Supply by Warranty or just go buy one at a local store, atleast 350w to 400w non-generic.
  14. StormBringer

    StormBringer TS Rookie Posts: 2,244

    He will have to replace it with an HP PSU most likely, as most HP machines use proprietary PSUs and boards which means that just going and buying a PSU will not work.

    About the surge protector thing, I'd have to see the article to be sure. when I hear "surge protector" I generally think of a power strip with built in surge protection. Although, the term can be used to mean the same thing as "breaker". To try to clear it up, this would be some type of device(a switch, button or fuse) that would stop the flow of current into the PSU in the event of a power surge. Most PSUs have a fuse, though I have seen more and more of them lately with a reset button(breaker), it still isn't that common, but I thought it worth mentioning.
  15. siggers

    siggers TS Rookie Posts: 30

    how can PSU's be proprietary??
  16. SubKamran

    SubKamran TS Rookie Posts: 166

    Special cables to plug into special slots on the mobo.
  17. JimShady23

    JimShady23 TS Maniac Posts: 373

    Not propritary....atleast on older P3 Systems

    I have taken a few HP systems apart in my day and the basic componants stand true as with any other PC built or pre-made....Well maybe not Sony...they like to do everything reloved arournd them....However the way they put these things togeather is a royal PAIN IN THE KEISTER !!!!! Removable brackets.....screws in awkward places.....Remove this to remove that ect ect....Its like a big puzzle. Now the only thing that might be odd about the PSU is its size since HP likes to cram everything in a tight package they might use a micro ATX supply.....Basically what I would reccomend to you since you are new to the computer feild is

    A) Get a pen and paper and jot down were every connector from the Power supply goes.....

    B) Start the prossess of taking out your PSU....In return jot down every screw you take out and every bracket you take out.

    C) Once you get the PSU out and disconected take it to a PC shop and let the determine weather it is a standard ATX or micro ATX power supply. ( Dont go all out and buy a $100 PSU get somthing conciderable since HP slaps just a big enough PS in there to make the computer work.....Mainly a low cost 300 watt PS would be more than enough.....$30-40 range will be sufficint)

    Good luck, and with the proper precautions and research dont be affraid to do anything yourself....Its not as hard as you think....They only way to learn is to do it can do all the reading you want, but until you do it you have no experience....Reading about what to do however will give you a good idea on the proper methods.....Maybe just maybe going into your PC and seeing the crap they install on a system you pay a premium price for will give you a push to build a system yourself next time around at the same or lower cost...with 75% more functuality, 50% more speed....and 200% upgradability compaired HP or any other premade Wal-Mart and Off TV PC....With the said, again good luck and welcome to the world of computers.......
  18. vietdraz

    vietdraz TS Rookie Topic Starter

    One last post for this topic. Must express my sincere appreciation for everyone participated, and happily report job is done.
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