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A couple of power supply questions...

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  • Stone
    replied
    OK, problem solved. After not finding a suitable i.e., fully working, P4 power supply in my stash pile I decided to rig a non-P4 model with the P9 motherboard power cable it didn't come with that the P4 models do have. So I cut the plug off the dead one and made one of these:

    http://www.gttkc.com/shop/index.php?...roducts_id=638

    That was easy enough and now my P4 is back in full operation.

    Leave a comment:


  • luckybob
    replied
    in all honesty, I haven't found it worth the trouble to fix ATX power supplies. At least not "standard" ones. I've done it once, to a 350w unit, but it was special. It had extremely high 5/3.3V rails and I needed it for a special project. It was HELL to replace the secondary caps. Took all afternoon. These little supplies are high quality and just plain work for older systems. http://www.newegg.com/Product/Produc...82E16817151117

    The power efficiency and stability of the latest units is practically unbeatable. The power supply in my "gaming" computer is 1200W, the fan runs at MAYBE 1000rpm, 92% efficient, and has a < 1% regulation and <25mv ripple.

    Leave a comment:


  • Stone
    replied
    It's all the same system, a Gateway, and it came with the Newton. The Newton does nothing when tested as you described. It even has a test button with a green pilot light that does nothing either.

    I think the ESP-300 is just the regular Chinese junk, by any name. But, hey, it still partially works. Probably not much longer, though, without some caps.

    Leave a comment:


  • Old Thrashbarg
    replied
    Think of this as the poor man's test.
    It's also of limited use on this sort of equipment, since caps will often still show full capacitance but have a high ESR, and ESR is quite an important factor here.

    The Newton units are good quality, and shouldn't have any problems with capacitors... I've only ever come across one dead one, and it had been hit by a power surge. You said you tried a different PSU in the one system, but did you do the same for this one?

    I'd also try hooking up a couple old drives or something to put a bit of a load on it, then power it up outside the machine (jump the green wire in the ATX connector to one of the ground wires with a paperclip or something) and see what happens...

    The ESP-300 model number sounds like it might be a rebranded Channelwell unit, but I'm not sure on that. Can you get a picture of the inside of it? It definitely does sound like bad caps on this one.

    Leave a comment:


  • Stone
    replied
    One is from a Gateway. It's a Newton Power Ltd., Model: NPS-160CB-1 A REV:00 and it's the totally bad one. Nothing obvious upon visual inspection. No burns, scorching or bulging, disfigured or leaking caps.


    The other is a MAX Model: ESP:300 and it works except the machine reboots upon DVD insertion. It has a few caps that ‘may’ be bulging just a bit and are therefore suspicious.

    Leave a comment:


  • barythrin
    replied
    It's not a perfect test (ESR is today's method) but you can do a simpler test of caps with a digital multimeter it just won't be able to prove if the cap is able to hold the full potential load that it's meant to. Think of this as the poor man's test.

    Leave a comment:


  • Old Thrashbarg
    replied
    Not really. To be able to properly test 'em you'd need an ESR meter.

    But have you actually pulled the covers and looked inside the units yet? Usually the caps bulge when they go bad, and are thus pretty easy to spot.

    Also, what specific PSUs are they? Chances are pretty good that I've repaired at least one or two of the same models, so I may be able to offer specific pointers for your units...

    Leave a comment:


  • Stone
    replied
    I don't have a cap checker, only a VOM. Is there any way to check caps with that?

    Leave a comment:


  • Old Thrashbarg
    replied
    I'd say about 90% of the time it's just bad capacitors. Sometimes you'll get a shorted rectifier or switching transistor, but such issues are considerably less common.

    Leave a comment:


  • Stone
    started a topic A couple of power supply questions...

    A couple of power supply questions...

    I've got some repair questions regarding ATX P4 power supplies.

    One is weak. In a machine with a CD-RW drive and a DVD drive the CD works fine but whenever I put a DVD into its drive the machine reboots. I determined that it was the power supply. Everything works fine with a new power supply. Any suggestions what to look for in this weak power supply to try and repair it?

    The other power supply is a no-go. The power button goes amber when I try to start the machine. There is no fan action. The only life other than the power button is the green pilot light on the motherboard. Any suggestions for a repair on this one?

    Thanks in advance.
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