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Power supply (PSU) concerns

By truffles
Mar 5, 2002
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  1. raybay

    raybay TS Evangelist Posts: 10,716   +6

    Varies widely and wildly. Get that information from the maker of the power supply. Much, much smarter to get one that doesn't require the fuse, as there are better, more protective methods.
    Anytime you can blow a fuse, you can cause a fire, and if you are not there to put it out, you lose everything.
    We just inspected the top 12 power supplies in our repair store room. None have user replaceable fuses.
    You are putting your system and ones you love in an unnecessarily risky spot over a 50 cent fuse, and a $55 power supply.
    There is a REASON why that fuse blew, and if that system is not restructured, you or someone could end up in a fire... or perhaps just a ruined computer and data.
     
  2. Tmagic650

    Tmagic650 TS Ambassador Posts: 20,934   +167

    Also something else in the power supply probably fried too, and if you replace the fuse it will just blow once more. Any power supply with a green LED visible in the back of the power supply is junk anyway
     
  3. kimsland

    kimsland Ex-TechSpotter Posts: 18,353

  4. AlbertLionheart

    AlbertLionheart TechSpot Chancellor Posts: 2,714

    Don't think he liked our collective (but consistant) advice!
     
  5. raybay

    raybay TS Evangelist Posts: 10,716   +6

    You can calculate the need, but you cannot detect the existing... usually, unless in the specs, you have no way to know... and if in the specs, they are usually not accurate... Most assembly lines have 7 choices. When they run out of one, they switch to the barrels with another.
    Best to plan on replacing the power supply when you get the computer... just mentally add $60 onto the price.
     
  6. xKrNMBoYx

    xKrNMBoYx TS Rookie Posts: 16

    Hi Guys I will be needing to buy a 700w PSU but I'm not sure which type to buy. Can someone help me. I need to know if my Computer will need a ATX or Micro ATX, or the size limit of the PSU.

    I have a:
    Compaq Presario SR5507F

    My computer is currently using a:
    OEM Lite On - Model # PS-5251-08

    The Dimension is about:
    5 1/2 Inch x 3 1/4 inch x 6 1/8 inch

    It would be nice if someone can tell me what exact type and PSU will be good/need.
     
  7. kimsland

    kimsland Ex-TechSpotter Posts: 18,353

  8. xKrNMBoYx

    xKrNMBoYx TS Rookie Posts: 16

    thank you for the link and help
     
  9. kimsland

    kimsland Ex-TechSpotter Posts: 18,353

    Thanks for the update :grinthumb
     
  10. xKrNMBoYx

    xKrNMBoYx TS Rookie Posts: 16

    well it didnt help much. I've checked compaq.com/hp.com's support and they dont tell me anything about power supplies.

    All it says is that my motherboard is a micro atx board. Does that mean I have to use a micro atx power supply?
     
  11. Tmagic650

    Tmagic650 TS Ambassador Posts: 20,934   +167

    Some of the older Compaq's used a "special" sized power supply. A standard ATX supply may interfere with the CPU cooler. You will just have to look and see if and ATX supply will fit
     
     
  12. AlbertLionheart

    AlbertLionheart TechSpot Chancellor Posts: 2,714

    Hi
    700 watt is going to handle just about anything your system will need.
    The dims you have given are for a stock PSU so any stock PSU will do so long as it is ATX.
    For brands I would always use Antec or Coolermaster for preference but you don't say where you are so I have no idea what you can buy.
     
  13. xKrNMBoYx

    xKrNMBoYx TS Rookie Posts: 16

    I live in the US. Ozark, Missouri to be exact.

    Nice to know I can buy a stock atx PSU..now I can go get one..thx
     
  14. kimsland

    kimsland Ex-TechSpotter Posts: 18,353

    That link I provided also had free instant online chat with an Online Support Technician
    They would have fully confirmed what you need, instead of waiting 5Hrs here
    By the way, for some reason, I've only just now got this reply
     
  15. xKrNMBoYx

    xKrNMBoYx TS Rookie Posts: 16

    i thought about that, but decided not to. I already know how much, which, PSU I'll be needing, but thanks for still coming and explaining
     
  16. kimsland

    kimsland Ex-TechSpotter Posts: 18,353

    Thanks for the update. Now resolved :)
    I just want to re-confirm to all others that reading the specs in the manual is the best starting point. Manufacturers such as Dell and Hp also have free online chat support
     
  17. raybay

    raybay TS Evangelist Posts: 10,716   +6

    You can use any ATA ver 2.00 or higher that has dimensions no larger than your current power supply, the power switch in the right location, and any fans blowing over the same area as hyour current power supply. Your Computer will not know the difference. A high quality power supply will usually have a more steadily reliable output. The output can be anything from 250 watts on up to 1000, if the dimensions remain the same, but 400 watts or greater in a quality product such as Seasonic, Corsair, Sparkle, FSP Group, OCZ, Antec, and about 40 others will do the best job. You do not need the most expensive. In fact you should be able to find what you need for under $70, and sometimes as low as $45 plus shipping.
     
  18. cubecompMTDX

    cubecompMTDX TS Rookie Posts: 88

    The power supply in my system is an @-POWER (Dynapower USA) 500w model with 28 amps on the 12v rail. On Newegg, it's $19.99. By looking at the reviews, and by my own experience with it so far, this thing seems to be really worth the price. It has 2 fans, it's cool/quiet running and actually has some weight to it compared to most PSUs in this price range.

    http://www.newegg.com/Product/Product.aspx?Item=N82E16817255010
     
  19. Rage_3K_Moiz

    Rage_3K_Moiz Sith Lord Posts: 7,286   +24

    Dynapower PSUs are trash. Some of their units even have bogus UL numbers. Not something I'd recommend even for a low-budget system.
     
  20. raybay

    raybay TS Evangelist Posts: 10,716   +6

    You always have to wonder what is in that box for $19.99. There is no way possible to build a decent ones with good components for that kind of money.
    In our experience, a Dynapower will always fail sooner or later. Check out their UL numbers and you know they have no problem committing fraud. So how does anybody know there are really 28 amps... just because they say so? There is no reason to trust a company that is known for publishing phoney numbers.
    The power output is uneven, leaping downward and upward all over the scale. They will work for a while on machines with limited graphics and connections. But to sell it for $19.99, NewEgg must make a profit... probably 25% to 33%. Shipping from China, and component parts take up the rest. So how does Dynapower make up the rest?
    How much does a new machine cost when that power supply misbehaves, and zaps your CPU fan or video graphics or DVD burner?
    Then there is always fire.
     
  21. cubecompMTDX

    cubecompMTDX TS Rookie Posts: 88

    In the reviews, people have run some high end video cards with this power supply... ones that require a lot of amps... such as this one. We know it can handle at least 22 amps...

    (5/5)
    "It just works. Resolved a low power issue I was having with a new graphics card(8600GT). The 8600GT wants 22 Amps on 12v rail. This PS solved that issue with head room amps to spare on the 12v rail. Tough to find a PS at this price range that does all that. NewEgg does it right... as always."

    (5/5)
    "Pros: Not one DOA, I have ordered tons of these for client builds and not one has quit on me yet! heavy and seems to be well built. Last a long time, Strong 12v rail.

    Cons: Don't care too much for the gold fan grills...

    Other Thoughts: I have powered 8600GT's, 9600GTs, with two drives, quad core CPU, many fans two HDDs and more! these babies can handle a lot of equipment. Really worth trying for the price!"


    I believe this PSU would last a lot longer than it's similar price range cousins. Throughout all of the reviews, there have been no reports of it catching fire, frying computers etc. If you want to see some cheapies that do the above check some PSU's from Coolmax, Logisys, Sunbeam/CaseGears.

    Coolmax CA-400
    http://www.newegg.com/Product/Product.aspx?Item=N82E16817159043&Tpk=coolmax ca-400

    Horrible reviews for a PSU... there are more bad reviews than good

    (2/5)
    "Pros: The only good thing about this power supply is the looks. Nice. shiney chrome. Also, Newegg is awesome when it comes to speedy delivery and rma's. I highly recommend them.
    Cons: After I installed this power supply, I smelt something burning. 5 minutes after that, the dang thing died on me. Glad it didn't ruin any other hardware on my system. Should have went with the worst reviews on this one. Don't try to be cheap and save a buck, not worth it! Also the power connectors are lame. They have some kind of sleeve on them that makes it hard to plug into anything."

    (1/5)
    "Pros: shiny

    Cons: Unexpected product change- From reliable to dead and worse!!! One was dead, two putting out killer overcurrent. Hope my new mb is ok. One got out in a customers box. darn it.

    Other Thoughts: Total 4 in a row bad! Have used dozens of these. Now I need to look for another cheep reliable PS. Not much of a selection, only 600+ to choose from. Not much of a refund after paying for all that shipping!!!!"

    Logisys 575w PSU
    http://www.newegg.com/Product/Product.aspx?Item=N82E16817170017

    (1/5)
    "
    Pros: Cheap.
    Cons: Very low quality, badly build, sloppy connectors are short, the dang thing blew up in a busrt of smoke and electric flame. It almost took out my whole new computer.
    Other Thoughts: I will never buy LOGISYS items again. Very cheaply made and dangerous."

    (1/5)
    "Pros: Cheap price

    Cons: System would not power on consistently. Had massive electric fire with smoke pouring out."

    (1/5)
    "Pros: Great price, good wattage, worked fine with no problems for 1.5 years, covered cables, lots of connectors, 2 fans

    Cons: I was sitting in my dorm room last night and all of the sudden smoke starts pouring out the rear fan of the power supply and fills the room, the smell of burning plastic ensues. I quickly run over and yank out the power cord (monitor went black but the fans were still running). I open it up and one of the red cables running to a hard drive was completely melted with the wire showing.

    Other Thoughts: I'm lucky my dorms fire alarm didn't go off, I didn't see any flames. I hope none of the components in the rest of the case are damaged. I never had it under a very heavy load."

    When I buy my power supplies, I look at the reviews. I was needing something inexpensive, wthis Dynapower PSU fit the bill perfectly. Most people have had a really good experience with this thing, and I believe it has a 2 year warranty, unlike the 1-year one that the other cheap PSU's offer. Like I mentioned before, it's quiet/cool running, has a bit of weight to it... the heaviest 20 dollar PSU I have ever seen, even the casing on it is strong, not thin like the other guys. Look @ my review on it (cubecompmtdx) for more detail. I was trying to keep the bill under $200 for my new upgrade of parts. If I would have bought something like a FSP unit or something expensive, the bill probably would've been $250-260, when I only had $200 to spend.

    Sparkle/FSP are great PSU's but FYI, they don't always last forever either. The last FSP unit I had magically turned itself into an electric fireworks show throwing sparks everywhere and pouring toxic smoke into the whole house, luckly nothing was fried because I was testing the unit.
     
  22. raybay

    raybay TS Evangelist Posts: 10,716   +6

    Any power supply can fail. Any one. But the good ones have long warranties and detailed specifications.
    But at $19.99, you know you are buying a future failure. You cannot build one for that and make a profit unless you cheat somewhere.
    The reviews you are looking at on NewEgg are usually made at the time of purchase. You don't see many taking the time to write a new review reporting they were wrong.
    We have already seen enough of them in our repair shops to know they are trash.
    Why not spend twice the money for something that works, or three times the money and get something that supports whatever upgrade you install.
    Buying a cheap power supply is simply wrong headed, because you are buying a future waste of valuable time while you hunt down a replacement.
     
  23. cubecompMTDX

    cubecompMTDX TS Rookie Posts: 88

    Some of the reviews are from people that have owned the unit for 2 years or more. If i had the money, i would buy better quality units, but right now... I can't afford much, so I have to buy what I can afford, and anything is better than nothing. Me and my friend Tim are always looking for bargains because we aren't rich. Tim is currently living in a shack on his parent's land because his house burnt to the ground and he didn't have homeowners insurance, and now he has severe R. arthritis and osteo-arthritis. I'm 17 years old, just got my drivers license a few days ago. We have never had problems with cheap parts, and certain cheap power supplies because we research our stuff really well before we buy. Tim has worked on computers for decades, and he pushes his stuff to the max, not to mention aggressive overclocking. He liked the deal i got on this unit. And actually I see a lot of people writing 2nd reviews to update how their product is doing, and in this case... most of them are updating to tell that the thing is 2+ years old and still working strong. I agree with your opinions on cheap power supplies, and I have seen my fair share of problems from certain ones. It's just like the emachines, they are very cheap, but not all of them fail. My grandpa has one from 2006 and it hasn't failed yet, but i'm ready to build him something new if it does fail.

    lol this is also a 7-year-old thread. The beginning of it started in early 2002!
     
  24. Rage_3K_Moiz

    Rage_3K_Moiz Sith Lord Posts: 7,286   +24

    You are confusing video card power requirements with system power requirements. When you see something like "The 8800GT needs 27A on the +12V rail", this does not mean the card itself draws that much current. If the 8800GT drew that much alone, then it would need approximately 320W of power on its own! The figure refers to the maximum amount of current drawn from the +12V rail by a system containing the card in question.

    FYI, the 8600GT consumes only a meager 43W, which is a little less than 4A from the +12V rail. The large current rating is the maximum current that may be drawn from the +12V rail by a system containing the card. It's also wrong, since the actual figure is 18A, and this is based on a system with a high-end quad-core CPU. So a system with a 45nm dual-core CPU will draw much lesser.
     
  25. raybay

    raybay TS Evangelist Posts: 10,716   +6

    Since you are determined to give it a go, please let us know how it turns out after a couple of years.

    Keep in mind that a bad power supply can wipe out your board or your graphics card.

    However, the NewEgg reviews are 5 positive and 11 negative. Do not misinterpret the length of use of "One Month to One Year" to be a year. This power supply was not sold 10 months ago. I suspect most reviews are closer to one week to one month.

    Dynapower is a fairly good company. Their high-end power supplies are good ones, but there is a mistake someplace for the UL numbers that don't check out.. I suspect they are trying to unload this power supply at a bargain price because it does not work well SATA. You have to jerry rig the system by modifying cables with extensions... and that voids the warranty. It is Not good for for power hungry graphics cards, because that supposed 450 Watt unit does not produce the high power when needed.
    For a normal use home budget computer, it should be fine for a couple of years.
     


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